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L IMP4 JATA cr C .rREAT. CREEK 9;LOOD CONTROL CPROJECT, Milford, Connecticut July 1984 COASTAL ZONrE INFORMATION CENTER HD 1676 .U62 H @D 1676 .U62 C @Department of c8 1984 @Environvnental cProtection July 18,1984 RE: Environmental Impact Evaluation Great Creek Flood Control Project Milford, Connecticut Dear Reviewer: The Department of Environmental Protection proposes to construct the project herein described to alleviate the-chronic flooding conditions currently experienced in the lower Great Creek drainage basin in Milford, Connecticut. Pursuant to Section 22a-la-7 of the Regulations of Connecticut State Agencies, this Environmental Impact Evaluation has been prepared and is being made available for public review and comment. A detailed evaluation has been made of the proposed action, its probable impacts and alternative actions which might be employed to remedy the deficient conditions in the project area. The findings of that study along with a description of the project area are contained in this document. Your review and comment on this project are actively encouraged. Written comments as well as any questions or requests for further in- formation may be forwarded to Frederick Riese, Department of Environmental Protection, 71 Capitol Avenue, Hartford, Connecticut, 06106. The deadline for submission of comments is September 7, 1984. Sincerely, Property of CSC t1brary Stanley/J@ Pac co U S DEPARTMENT OF COMMERCE NOAA COASTAL SERVICES CENTER 22134 SOUTH HOBSON AVENUE CHARLESTON SC 29405-2413 CONTENTS Summary Distribution List Introduction .............................................. Page 1 Project Setting ............................................... 4 Proposed Great Creek Flood Control Plan ......... 00** 27 Analysis of Alternative Flood Control Strategies*.'.*.*.:::::: .... 33 Project Impacts ............. o........ ...... ...... o.. 41 Public Participation...... ........... ........ 50 Permits and Approvals ........................ ...... 51 Irreversible and Irretrievable Commitments ....... 52 Relationship to Land Use Plans and Policies ........ o .......... 53 Costs and Benefits.... oo ... o ....... o.oo .......- .....o ...... 54 Appendices: A - The Development and Function of the Self- regulating Tide Gate B - Marsh Restoration at Great Creek C - Results of Flora and Fauna Survey D - Coastal Management Consistency Determination E - April 1984 Revised Cost Figures F - Public Hearing Figures 1. - Location of Project... o.o ......... Page 3 2. - Meadows End Marsh, 1837... ... o..0 ... 5 3. - Great Creek Project Area ......... o... ....... 6 4. - Frequency of Flooding from Hurricanes and Storms ......... 12 5. - Locations of Leased Oyster Beds and Shellfish Concentration Areas ........ oo .......o... o........ o.. 22 6. - Diversions from Great Creek Watershed ........... - ...... 36 7. - Construction Equipment Noise Ranges...... .... 44 8. - Location of Proposed Disposal Area........ ... 46 Tables 1. - Elevations of 260 Homes ..... ooo.oo ........ oo ..... ....Page7 2o - Storm Discharges... o .... o-o- .... o.oo is 3o - Runoff, Storage, and Flood Stage for Various Storms.;,....: 16 4. - Demersal Finfish Species.... o_o ................ ... 24 so - Epifaunal Invertebrate Species. ................ o .......... 25 SUMMARY In response to continuing chronic flooding problems exper- ienced by the residents of the lower Great Creek drainage basin in Milford, the General Assembly authorized funds through Special Act 83-17, Section 2(e)g, for the construction of drainage im- provements in that watershed. These improvements will be fi- nanced in their entirety with State funds. Great Creek drains a watershed of 504 acres in south central Milford. Residential development at high densities has taken place in the southern portions of the basin near beaches on the Long Island Sound shorefront. These structures are located at very low elevations on artificial fill placed in a former tidal wetland. The combination of these low elevations and poor drain- age from the basin caused by undersized and frequently clogged outlet works produces frequent inundation of yards, streets and occasionally homes. Milford public works forces are also kept busy cleaning and maintaining the outlet channel which can become blocked by sand as often as thrice per week in the spring. The firm of Diversified Technologies Corporation was re- tained by the State to develop and evaluate options to correct these flooding problems. Numerous plans, both structural and non-structural, were considered. The selection of an individual flood control strategy involved coordination with town officials, a public hearing to gather the input of the residents in the project area, and the continuous evaluation by the Department of Environmental Protection as the proposal evolved. This selec- tion process yielded the proposal described in this report. Increased protection from flooding for local residents will be accomplished by relocating and enlarging the discharge outlet from the basin. The existing outlet works will be replaced by a culvert of considerably larger capacity located at the eastern edge of the Silver Sands State Park beachfront. Discharge capa- city will be increased from the existing 86 cubic feet per second (cfs) to 590 cfs. The new box culvert will run for 315 feet and will be 5' by 161 in cross-section. The existing outlet works, measuring only 48" in diameter at its outlet pipe, will be aban- doned and plugged. Regulation of incoming tidal flows will be maintained using two 72" x 54" self-regulating tide gates. Two manual sluice gates of the same dimensions will also be incorporated to serve as a back-up system and in the event of maintenance or repair of the tide gates. Both sets of gates will be located in a concrete vault built into the upstream end of thebox culvert. To direct the flows in Great Creek to this relocated outlet, 3,190 feet of new channel will be excavated. The main portion of this channel will intercept the East Branch of Great Creek, bypass the existing confluence of the two branches, And deliver this flow to the West Branch. Small segments of the lower por- tion of the West Branch will also be rechanndlized. The new confluence will be formed within the existing West Branch. From this point,, the total creek flow will be diverted westward and then southward to the box culvert. The channel will average 30 feet in width above the new confluence and be 40 feet wide from that point to the culvert. Upon outletting from the box culvert, the flow of Great Creek will cross Silver Beach and empty into Long Island Sound. Two timber-sheeted training walls will be erected on Silver Beach to confine the creek channel. These will be at a spacing of 18 feet and be,located adjacent to the park property boundary. Benefits from this project will accrue. from several ac- counts. Foremost, of course, is the extra flood protection. Whereas at present, storms as frequent as the semi-annual event can overwhelm the ability of the existing outlet to release the flows and thereby cause neighborhood flooding,. chronic flooding from such high-frequency, low-magnitude storms will be eliminated as a result of a sixfold increase in outlet discharge capacity with the new structure. For more significant stormso, of the magnitude of the 10-year event or larger, drainage of excess waters impounded within the marsh will be accomplished much more rapidly than is presently possible. Thus, for the largest stormst the duration of flooding can be reduced from a period of several days to within-one tidal cycle. In addition to relief from flooding, the second major . goal of the project is the restoration of the Great Creek marsh to a healthy, tidal salt marsh. This system has historically been characterized by regular tidal flushing and saltmarsh vegetation. Gradual degradation to its present state followed as a result of filling within the marsh and the near elimination of tidal flush- ing due to the existing undersized, frequently clogged culvert. The saltmarsh species died and were replaced by a monoculture of the reed Phragmites. Biologic diversity and productivity de- clined. Today the Great Creek marsh is a severely degraded ecological system. The opportunity to restore and upgrade the marsh to its previous saltmarsh nature appears promising. The factors which will allow this improvement to be realized are the greatly en- larged culvert capacity and the inclusion of self-regulating tide gates. The self-regulating gates, unlike standard tide gates, allow for a two-way exchange of water between the marsh and the Sound. Therefore, the large volumes of saltwater re- quired to sustain an active saltmarsh vegetative assemblage can be admitted upon each incoming tide. The resultant inundation of the marsh will lead to the gradual die-off of the invader species and their replacement by characteristic saline-dependent vegetation. Reversion to salt marsh carries other pluses for the Great Creek area. Chief among these are substantial reductions in the potential for and intensity of marsh fires, a less favorable habitat for the breeding of mosquitos, and the improved aes- thetics of a salt marsh. Town public works expenses should be reduced as a result of the abandonment of the existing creek outlet. No longer will frequent visits by the town maintenance forces be necessary to open the blocked channel or pipe. Finally, the reduced threat of flooding should provide an impetus for neighborhood improvements. The incentive for home- owners to upgrade their homes and properties will be enhanced. Both these improvements and the general reduction in the occur- rence of flooding will foster increased property values. The grand list of Milford and the tax revenues realized by the city will eventually also reflect these benefits. Short-term and long-term impacts will arise as a result of the implementation of this project. .The short-term impacts include the noise, traffic and dust experienced in the project area during portions of the six month construction interval, exhaust emissions from construction equipment, the closing or partial closing of East Broadway to traffic during placement of the box culvert, and sedimentation in and from the basin. Fol- lowing these construction impacts and the activition of the new channel and outlet, a gradual die-off of the reed growth in the marsh will produce floating debris which will be both unsightly and which may require extra maintenance to clean it from the gate structures. The only long-term adverse impact meriting consideration is the commitment of an eighteen foot wide strip of State beach to permanent use for drainage. Approximately 360 square yards of beach area will be involved. Conversely, the abandonment of the existing outelt channel across Fort Trumbull Beach will add a similar amount of usable space to that private beach. Revised cost figures for this project indicate a price tag of $717,000 (April 1984). EIE Distribution List Federal Agencies This document will be a part of the application to the U.S. Army Corps of Engineers for the required 404 permit and will be reviewed by that agency and other appropriate Federal agencies at that time. State Agencies - Office of Policy and Management Gary Kingr Comprehensive Planning Division - Council on Environmental Quality Domenic Forcella, Executive Director - Connecticut Historical Commission John Shannahan, State Historic Preservation Officer - Department of Agriculture John Volk, Aquaculture Division - Bureau of Public Works Morgan Elyr Design and Review - Department of Environmental Protection William Miller, Parks and Recreation- Paul Perlsweig, Solid Waste Management municipal Officials Mayor - Alberta Jagoe City Clerk - Margaret Egan Conservation Commission Chairman - Bartley Block Flood and Erosion Control Board Chairman - Edmund Colangelo Director of Public Works - John Donnelly City Engineer John Casey City Planner Wade Pierce Chief Environmental Officer William Howard Alderman - James Amann Alderman - William Engle Alderman - Nancy Murino State Legislators Thomas Scott - Senator, District 14 T.J. Casey - Representative, District 118 -iv- Organizations and Individuals Dr. Murali Atlurur Diversified Technologies Corp.j Inc. Thomas Steinke, Fairfield Conservation Commission William Ziebell, Silver Sands Association Public Notices Public notices announcing the availability fo this document have been published in the following media: New Haven Register (7/26, 8/2, 8/9) Milford Citizen (7/27, 8/3, 8/10) Connecticut Law Journal (7/24) -v- INTRODUCTION The Department of Environmental Protection has been directed to take corrective action to alleviate the chronic flooding conditions which occur in the lower reaches of the Great Creek watershed in Milford. Funding for this work has been provided by the Connecticut General Assembly through Special Act 83-17,. Section 2(e)9. This project will be financed totally with State funds. Great Creek drains a watershed of 504 acres in the south central part of Milford before emptying into Long,Island Sound 1,900 feet to the east of Silver Sands State Park. The maximum dimensions of the watershed are approximately 7,000 feet north- south And 5,000 feet east to west. The boundaries of the water- shed are shown in Figure. 6. Residential development is the predominant land use accounting for almost 60% of the watershed. Open space, consisting mostly of the 105 acre Great Creek marsh, and the municipal landfill are the other major land uses. Thirty-three percent of the watershed is undeveloped. Most of the Great Creek drainage basin lies at very low elevations. The highest point, 92 feet above mean sea level, is located at the northernmost point in the watershed near Tower Street. The lowest point occurs along the Long Island Sound shorefront. It is at the lower elevations that chronic flooding problems are experienced. Virtually all of the Great Creek marsh lies below elevation 5.0 feet with the majority of it being less than 3.0 feet above mean sea level. Around 1915 - 1930, fingers of fill were extended northward into the marsh from the barrier beach on which East Broadway is located. Although the barrier beach is at elevations which generally range from 81 to 91 above mean sea level,. the fill was placed to elevations only margin- ally higher than the marsh itself. Numerous dwellings on small lots were constructed on these fill extensions. Today there are 260 affected homes in the project area located along the north side of East Broadway, the west side of Surf Avenue and the 13 dead end streets extending northward into the marsh off East Broadway between the state park and Surf Avenue. . Because of their low.elevation and the poor existing drainage from the Great Creek marsh system, many of these homes experience flooding on a semiannual or more frequent basis. The flooding consists of property inundation, submerged roadways, porch and storage area flooding and, for the more severe storms, water in the actual living spaces of dwellings. The problem is compounded by the exceedingly slow drainage from the basin which can extend the period of inundation to as much as three to five days. The existing outlet structure for Great Creek consists of a 61 X 51 box culvert passing beneath East Broadway, a tide gate chamber, and a 48" diameter concrete pipe which outlets into an open channel across Fort Trumbull beach. Due to its deteriorated and non-functional condition, the wooden flapper-style tide gate has been permanently locked in an open position. Before this was done in 1977, the gate had locked itself into a semiclosed posi- tion due to sand and debris in the outlet. This had further reduced the poor drainage characteristics of the outlet and had totally eliminated any tidal flushing. Even with the flapper gate locked open, the 48" concrete pipe and the channel into which it discharges still remain as serious constrictions to free drainage. Shifting sand frequently blocks the open channel. This sand comes from two sources. Littorally transported sand can be drawn up the channel as the tide rises and waters from the Sound enter Great Creek. The channel is also surrounded by beach sands built up to higher elevations which can either slough off or be blown into the channel. Once in the channel, some of this sand is invariably carried into and deposited in the pipe. The discharge flow from Great Creek has insufficient velocity to cleanse the outlet of this debris. The result is partial or occasionally total block- age of the pipe or channel which inhibits drainage and tidal interchange producing elevated water levels and stagnant condi- tions in the marsh. Town of Milford public works crews are frequently summoned to the area to remove sand blockages in the channel, as often as two or three times per week in the spring. Alleviation of the flooding problems at Great Creek has.been the subject of several studies done since the early 1970's. In addition, many of the evaluation concerning the closure of the Milford 1andfill and the development of Silver Sands State Park have also considered the impacts of these plans upon the drainage of the Great Creek watershed. As presently proposedr closure of the landfill in a manner which will prepare it for park develop- ment will add 34 acres to the Great Creek drainage basin, enlarg- ing it to 538 acres. This will increase by approximately 6.7% the volume of incident precipitation and eventual runoff that must be stored in the marsh and discharged through the outlet. Park development will further increase runoff by adding to the area of impervious surfaces in the basin. For this reason, it is imperative that relief measures be undertaken before the landfill is closed and the park developed. This necessity is recognized by Special Act 83-17 which specifically links the flood control project to the landfill closure by providing a combined authori- zation of $6,500,000 for the two projects. -2- LOCATION OF PROJECT I 1 6 "if L 0 ...... I - - - - - - So It 106$00900___- _4___ a.-Sees see 9.0106; 1 L I log' 0 % II a @feet Go/ arts 0 Ii.soor -seat 0 w 11 F. 11, 0 _--i- 2_12 III I ISO L1 A 0.0 w6%0..fi,o 6.4'. r. evil& a _1L.- - - @ - % .0.0. 0 "a I ': go, Sol$ H A If "46 I doom.% GS849646040 .0 .9 I 417 .."o" 41-----T a V..44 I a 14 "'a aa 01so "06"e, 1446"d "S"Sog a 8164658 A L -0 000969 B."'. Goes. & -0 GBOODS, 0_4 0 L IE S C x ab IIf ter a &rat I'm 14 &No$ at& 0*4, so., Ia 0.0 $686,06 A j :.j C 'j.. _ D *..*$a ".go. I I % post Figure @--Great Creek ........ x Map of the State of Con Drainage Political Basin .a 04 Go' PROJECT SETTING The immediate project area consists of the 105 acre Great Creek marsh and the barrier beach which separates it from Long Island Sound. This marsh is the remaining portion of a previ- ously extensive tidal marsh system known as the Meadows End Marsh. As shown in Figure 2, an 1837 U.S. Geological Survey map, the Meadows End Marsh included all of the area between the pre- sent locations of Nettleton and Surf Avenues and was fronted by a barrier beach broken only by the outlets of Great Creek and Fletchers Creek. Under the then-existing natural conditions, sufficient tidal flushing was available to maintain the whole marsh as a healthy, functional tidal marsh ecosystem. Gradually the area was developed resulting in the loss of most of the marsh, the degradation of the remaining area and the evolution of the present hydrologic conditions. East Broadway was constructed atop the barrier beach. Following this, much filling of the marsh behind the beach was done over the entire length of this stretch. Homes were constructed both along the barrier beach and on the newly placed fill. The establishment and gradual expansion of the Milford Landfill consumed most of the remaining wetlands in the western half of the marsh and eliminated much of the length of Fletchers Creek. Substantial alterations subsequent to the establishment of the landfill in the late 1940's include the destruction of the summer homes and cottages south of the landfill by Hurricane Diane in 1955 and the construction of the East-West Service Road in the early 1970.1s. At various times between the early 1950's and 1972, the sewage treatment plant,, pump station, dog pound and refuse shredder were built on landfilled marsh. Following the destruction by Hurricane Diane, the State of Connecticut acquired those cottage sites along East Broadway west of the pump sta- tion, together with adjoining interior properties, to form Silver Sands State Park. Extent of Existing Flooding Conditions There are 260 affected homes in the project area. 1 These are located along the north side of East Broadway, the west side of Surf Avenue and on Pearl, Cooper, Hanover,, Chetwood, James, Gardner, Silver, Blair, Tremont, Maddox, Scottr Caroline and Pleasant Streets, all of which run north off of East Broadway (See figure 3). Although East Broadway and Surf Avenue run at elevations which generally exceed seven feet (MSL) , the thirteen side streets off East Broadway are mostly at elevations below 5_0 feet as is the extreme southern portion of Surf Avenue. 1Diversified Technologies Corporation, Pre-Design Report, Flood Control-Great Creek Silver Sands State Park, Milford, ET-, 1983, -4- 000" Now -Nov _zwlr- Z" IML Ul FT*3H FORT TRUM 3,L=- LZA - =dg Tmmd ftrn US C*W &n", WT GREAT CREEK PROJECT AREA (including pkww*d im ments) FIG. awl CA lu Table 1 shows the elevations of the 260 homes in the project area. Almost two-thirds of these homes are located within the 5 foot elevation contour. This means that these homes are sur- rounded with water even in a comparatively minor flooding epi- sode. Such minor, high frequency events also inundate the neigh- borhood streets listed above. Flooding of the actual living space of dwellings is not as common. -As shown in Table 1, only seven homes have sill eleva- tions below 5.0 feet (MSL). only nine are below 5.1'. Yet a considerable number of homes in the East Broadway neighborhood have experienced floodwaters in their first floor living areas in the more substantial storms. Table 1 2 ELEVATIONS OF 260 HOMES Sill Elevation Contour Elevation of homes of homes Below Elevation 4.0 0 41 Between 4.0 and 5.0 7 127 Above Elevation 5.0 253 92 Data on the f requency at which flooding of various magni- tudes occurs is presented in the following subsection. These flood elevations result from the combination of the given pre- cipitation event and the hydraulic or drainage characteristics of the basin. It is the latter factor which produces the chronic flooding problems peculiar to the lower Great Creek basin. More specifically, the outlet from the Great Creek marsh is deficient in capacity and constricts flow severely enough to produce the flood elevations which inflict hardship on area residents. In a diainage study of Great Creek done for DEP in 1974, C.E. Maguire listed the following two factors as contributing to the drainage problem in the lower reaches of Great Creek. "l. The outlet of Great Creek into Long Island Sound is vulnerable to sanding in by littoral currents of the Sound. This greatly reduces the discharge capacity of storm runoff from the watershed. The partial blockage of the outlet reduces flow velo- cities in the culverts and brook channel, which in turn leads to settling out of suspended particles (silting) carried by the storm runoff, reducing the discharge capacity of the drainage installa- tions even more. 2Ibid., p. 91. 3C.E. Maguire, Drainage Study, Great Creek, Silver Sands State Park, Milford, Connecticut, September 1974, p. 12. -7- 2. A conglomerate of box culverts, tide gates, junc- tion boxes and round concrete pipes presently in existence between the inlet to the 61 x 51 box culvert and the outlet pipe at the sound, causes very high friction losses (i.e., has poor hydrau- lic characteristics)." The problem of the maintenance of the channel was again discussed in a 1978 report by C.E. Maguire. "The level of the sand on the shore of the Long Island Sound adjacent to the outlet of the 48" pipe (Great Creek outlet) is several feet above the top of the pipe. An outlet channel from this pipe end toward the Long Island Sound is being maintained by Town forces by means of a f ront end loader which is brought there after those storms whose wind direction and accompany- ing high tide inundate the outlet. Wave action from those storms has a leveling effect on the sea shore and fills the manmade depression maintained in the shape of a channel and the depressed outle t pipe. The velocity head of the Great Creek flow is generally insufficient to force the sand away,from the outlet. Under these conditions, the outlet pipe is then closad and buried with several feet of the shifting sands." The following photosi, also from the 1978 C.E. Maguire re- port, show the existing channel as it outlets from the 48" cul- vert and a-s it crosses the beach. Thus, the existing problem can be, in very large part, attributed to an outlet works which is undersized and is designed in such a way as to produce high hydraulic friction losses and to the channel infilling problems which further reduce the hydrau- lic capacity of the outlet and which require frequent main- tenance. Flood Elevations and Frequency Having discussedthe manmade factors which contribute to the flooding at Great Creek, i.e. the deficiencies of the existing outlet structures, let us now look at the natural inputs upon which the drainage system is superimposed. These factors include the runoff characteristics of the basin, the tidal regime in Long Island Sound, and the storm events, either coastal, inland, or a combination thereof, which supply the basic ingredient of a flood, which is water. 4 C.E. Maguirer Drainage Study, Great Creek, Milford, Connecticut, March 1978, p. 4. -8- 14 5 Lop . es" t, ptpj L,17 ei Outlet of Great Creek into Sound at Low Tide .077 d i I, (C) 4K @7. x A &S.- Great Creek Tidal Flood 1-4 pr I A Low Tide and Zero Storn (H) Tributary To Great Creek A V@ 'A v\ (I) Tributary to Great Creek (J) Tributary to Great Cree The Great Creek basin can be divided into two subbasins each of which is drained by one of the two branches of the creek. The East Branch drains the greater fraction, 292 acres or 58% of the watershed including the northernmost portions extending to Tower Street and areas as far east as Seaside Avenue. The West Branch drains 209 acres or 41% of the watershed including the eastern portions of the landfill property. It is the West Branch that will receive runoff from an additional 34 acres of the landfill site following its closure. The final 4 acres or approximately 1% of the drainage basin lies below the corifluence of the two branches. Analysis of the runoff characteristics of both branches shows greater runoff and faster collection from the more heavily developed eastern sub-basin. Runoff coefficients for the two branches computed as per ASCE Manual 37 are 0.52 for the East Branch and 0.38 for the West Branch. The times of concentration for the East and West Branches are 46.4 minutes and 82.6 minutes, respectively. The East Broadway residential neighborhood is vulnerable to flooding from both coastal and inland events. These events are often coincidentr especially for the larger storms including hurricanes, although this is not necessarily so. In addition to the possible superimposition of coastal and inland events, the tidal cycle also exerts-an additive effect on water levels exper- ienced along East Broadway and within the Great Creek marsh. This is true both for storm surges imposed on high tides and for interior drainage from the marsh as it is impeded by elevated water levels in the Sound. From the coastal side, the elevation of the floodwaters produced by storms of various frequencies is given in Figure 4. As this figure also shows, for the Silver Sands area, mean high water is 3.51 MSL with the mean spring high tide at 4.21. Spring high tide is experienced twice daily for approximately three days out of each month. From this point, the level of high tide grades back to mean high tide in approximately a week and then falls to its lowest point about two weeks after the spring tide. Of course, the tidal levels actually experienced on any given day may deviate greatly from the normal values as they are influenced by wind or storm conditions or even by storms far out at sea. The shorefront along East Broadway is subjected to storm driven waters reaching elevation 6.751 above mean sea level approximately once per year. Following the curve plotted in Figure 4, the two year storm can be expected to produce waters to elevation 7.21. Once every ten years, on the average, flood- waters to 8.41 are generated by a coastal storm or hurricane. This particular frequency storm is very important because it is at this elevation that coastal waters will overtop East Broadway and flow overland into Great Creek. Figure 4 also shows that the storms which can be expected to recur at 50, 100 and 500 year intervals will generate floodwaters to 9.71, 10.41 and 13.81, respectively. lit lit ... .... .... . I F5 HE .... .... .. IUW, .. .... .... . cf. m: 11iEl T P. ill M! ..4 W., 1 1: :11 Ii6 pit :o.. I I T1 J-1 FREQt E it HURRI .. .... FLOOD il !j ji SILVER litI MILFOR At -VIAT AH li, rill i I -0 .-1. flit 11: 1 @!l FIGURE: 4j 71, dl DIVERSI u NQBJ 112 1 2 5 io 25 50 10 For storms which generate storm tides of less than approxi- mately 8 feet, the barrier beach along East Broadway acts as a protective dike for the homes north of it. The existing channel and constricted outlet prohibit elevated water levels in the Sound from being transmitted into the -Great Creek marsh and causing.flooding there. Thus, the same feature which has reduced tidal flushing and caused marsh degradation has also served a beneficial function in protecting the marsh-adjacent homes from the transmission of elevated Sound-side water levels into the marsh. As mentioned above, storms which produce tidal flooding elevations in excess of 8 feet will overtop the East Broadway barrier beach. Storms of this magnitude will occur at a fre- quency of once per decade over the long term. East Broadway itself is at elevations of between 7.0 feet and 8.0 feet through- out the project area except at the extreme eastern end where it drops to 6.5 feet at its junction with Surf Avenue.. North of East Broadway, the barrier beach drops off in elevation fairly quickly. It is to the south where the maximum elevations are attained. The homes along the south side of East Broadway are constructed on the highest strip of the beach. The crest of this. beach reaches its minimum elevation of just over 8 feet at Pearl Street on the west end and at Blair Street, the first street to the west of the existing outlet. Most of the beach tops out between 8 feet and 10 feet above MSL. The highest points occur toward the eastern end between Tremont and Pleasant Streets. Here the crest is above 10 feet, reaching 11.3 feet at Maddox Avenue. The height of the beach sets the effective maximum level of flood protection which can be provided from coastal storms. In order to increase the height of the beach, several very expensive and/or socially unacceptable steps would need to be taken. These would include either acquisition and removal of some structures along East Broadway or structural modifications and partial burial in order to strengthen and floodproof the homes and raise the berm elevation between the houses. In contrast to coastal flooding in which precipitation plays a very minor role, inland flooding is the result of individual or collective precipitation events. Inland flooding results when incident precipitation in the basin produces runoff at rates which exceed the discharge capacity of the existing outlet. With the existing outlet, overtopping of the Great Creek channel .begins with any flow exceeding 77 cubic feet per second (cfs). Diversified Technologies calculated that, with flooding in the basin to eleyation 5.0 feet, the discharge through the outlet is only 86 cfs. 5 Diversified Technologies Corporation, Pre-Design Re2ort, Flood ContrOl-Great Creek, Silver Sands State Park, Milford, CT, 1980, T. _48. -13- IDENTIFICATION OF WASHINGTON COASTAL NOV 25 1967 DUNE SYSTEMS AND ASS0CIATED WETLANDS By Louis W. Messmer and James B. Phipps Grays Harbor College Aberdeen, Washington September 1984 State of Washington Department of Ecology Olympia, Washington U.S. DEPARTMENT OF COMMERCE NOAA Department of Ecology COASTAL SERVICES CENTER 2234 SOUTH HOBSON AVENUE Contract No. C85-025 CHARLESTON, SC 29405-2413 QH 541.5 .S26 M4 1984 TABLE 2 STORK DISCHARGES--cubic feet per second Cast Branch Went Branch @_@ast & West Branch, LC 292.5 225.0 2 7 1 ;Q2. acres acres --acres acres acres acres Treq Without With Without Witn without With ance year;1 Diversion-Diversion Ditersionj DiversionlDiversion Diversion 50 2 213 172 79 224 249 163 199 20 5 289 235 103 135 61 106, 300 333 218 268 FJ 10 10 342 275 122 159 '72 224 353 393 256- 315 4 25 4.03 321 146 191 87 150 423 470 310 380 2 so 456 365 165 215 97 169 478 531 348 426 1 100 510 402 183 239 10 8 188 531 590 387 47S acfs values computed tr-eating the entire drainage area'asaningle uftit.@. b.Without Landfill Closdre and Park development south of Service Road. C6.With Landfill Closure and Park development south of Service Road, Source: Diversified Technologies Corporation, Pre-Design Re2ort, Flood Control Great Creek, Silver Sands State Park, Milforilr CT, November 1983', p. 37. ,76s@ac@re7 acres..,,., ame out witn I Fcha @Wj . A'.' 249 3373 RUNOFFr STORAGE, AND FLOOD STAGE FOR VARIOUS STORMS FLOOD CONTROL-GAEAT CREEK TABLE tj Stillwater Flood Elevation for Existing Conditions (502.0 acres) (Total Storage in Great Crook Basin) Volume Storage of with water .24 hour Runoff 8 elev 4.2 Total Flooding % Freq. precip. c - 0.46' (MSHW") Storage. Stage chance years Inches Ac-ft. Ac-4t. Ac-4t. (NGVD) 50 2 3.3 63.5 96 160 4.82 20 5 .4.3 82.B 96 179 5.00 10 10 5.0 96.2 96 192 5.10 4 25 5.7 109.7 96 206 5.24 2 50 6.3 121.2 96 217 5.33 1 100 7.2 138.6 96 235 5.47 MEAN SPRING HIGH WATER Note: Table assumes pre-storm water level in marsh at 4.2 feet. Thus, all internal storage Volume below this elevation is consumed before storm. Total storage (column 6) equals storm runoff contained in the marsh basin plus tidal storage at mean spring high water. Source: Diversified Technologies Corporation, Pre-Design Report, Flood Control - Great Creek, Silver Sands State Park, Milford, CT, November 1583, p. 50. composed of material eroded from both. The landward end consists mainly of medium sand. Toward the seaward or island end, the tombolo grades into a mixture of more gravelly materials and boulders eroded from the island. Low tide exposes the tombolo while at high tide it is submerged. This feature appears to be stable or at least in dynamic equilibrium since 1929.'_ Charles Island also operates to protect The Gulf and its beaches from westerly waves and storms. Charles Island appears to be an offshore expression of a till ridge whose mainland extension appears across Milford Gulf. The island is surrounded by a lag concentrate of gravel and boulders left behind as the fine material was eroded away. This lag concentraV acts as an impact absorber to protect and stabilize the island. West of the tombolo, longshore currents have heavily eroded the beaches removing much of the finer materials. Erosional rates of up to 3 feet per year were experienced until most of the beach material was removed. On the eastern side of The Gulf we f ind a wide beach and a depositional environment at the northern end of Gulf Beach grad- ually grading into an erosional area of thinning beach as -one heads south toward Welches Point. , Widths of 100 1 to 2001 are found at the northern end while to the south the beach has slim- med to 20-30 feet, becoming less sandy as one progresses. Ap- proaching Welches Point, the beach is nearly all stones. This natural stone armoring, assisted in some areas by some dumped boulders and old timber lagging and by we 11-establ i shed vegeta- tion, has kept the beach stable. Welches Point itself is pro- tected by granite and mortar slope paving, steel sheet piling, a dumped boulder revetment and three granite block spur groins of approximately 100 feet in length. These have been sufficient to hold the point against any losses. Along the northern perimeter of The Gulf, we f ind a gen- erally healthy beach. Traveling eastward from the tombolo across Silver Beach, the beach widens to approximately 130 feet at the eastern boundary of the State property and maintains a 75 to 100 foot width above mean high water across Silver Beach. Texture is slope dependent with very fine sands in the flat intertidal area, fine to coarse sand above M.H.W. and some gravel or even small stones in the steepest portions of the beach. Proceeding eastward, the present Great Creek outlet crosses the beach in a depressed channel slightly below the prevailing beach grade. Across Great Creek, Fort Trumbull Beach widens out 7C.E. Maguire, Silver Sands State Park, Proposed Dredge Project Environmental Assessment Statement (DRAFT).,, August 1973, p. 11-2. 8 Ibid., p. 11-2. -17- to 150 feet. This wide.-healthy beach extends eastward to Burns Point and the entrance to Milford Harbor and Gulf Pond. Waves are the major erosional force acting upon the beach in the project area. The size and power of the waves is determined by the strength, fetch and duration of the winds driving them. U.S. Weather Bureau records from New York City give the following data on wind direction in western Long Island Sound. originating Wind Percent of Total Direction Wind Activity North 14 Northeast 5 East 5 Southeast 5 South 13 Southwest 14 West 15 Northwest 29 100 of these wind directions, those f rom the W, NW,, N and NE blow of f shore and, therefore, do not generate waves affecting Connecticut beaches. Easterly and southwesterly winds have fetches of only 2.5 and 3 nautical miles, respectively, at the project area and thus do not produce waves as large.as the S and SE winds which can blow unrestricted for distances of 12 and 22 nautical miles, respectively. Although the southerly winds are the more frequent (13% of total wind activity), the greater fetch to the southeast has produced the most destructive storms affect- ing this area. Tidal currents in the study area are not strong enough to erode beach sediments but can transport sediment once it has been lifted into suspension by waves or other disturbances. Jacobsen found that The Gulf was an area of complex current patterns which are influenced by winds, especially those from a southerly direc- tion. Despite this complexity, a general clockwise circulation pattern was found to exist in the area. Maximum recorded current velocities during the Jacobsen study did not exceed 0.6 feet per second. The Gulf was noted as an area of relatively stable shoreline due to the protgction afforded by Charles Island, the tombolo and Welches Point. 9 Nathan L. Jacobsen and Associates, Study of Shoreline Erosion and Shore Protectiont Milfordt Connecticut, 1981, p. V-4. _18- Flora and Fauna The project environment for the Great Creek drainage im- provements occupies two distinct ecological settings. Most of the work will occur within the Great Creek marsh. The remainder of - the project, namely the open outlet channel and its timber training -walls, will cross a sandy beach. Beyond the point of the physical termination of the project at the end of the train- ing walls, the discharge flow from the creek will cross an area of sand flats and finally enter the waters of Long Island Sound. Each of these areas is discussed below in terms of the plant and animal species for which they provide habitat. --Great Creek Marsh-- The Great Creek marsh system consists of approximately 105 acres of formerly tidal wetlands. Due to restrictions on tidal interchange and on freshwater drainage out of the marsh, these wetlands have lost their salt marsh characteristics and been converted to freshwater wetlands. The constricted drainage has also operated to produce an elevated water table within the system which has retarded the growth and vigor of the freshwater vegetation. Today, the Great Creek system is dominated by fresh- water species and is mapped and regulated as designated inland wetalnds. one small zone of diminished saline influence yet remains,, however, at the confluence of the two branches of Great Creek. This area, being closest to the outlet, receives the maximum amount of saltwater influx and the lowest level of dilution. Yet even at this station, the salt marsh grass Spartina is confined to a narrow fringe along the creek and is generally overshadowed by Phragmites. Due to its inadequate capacity, clogging.problems and malfunctioning tide gate, the present culvert simply cannot transmit sufficient volumes of saltwater to support saline- dependent species in the marsh. An ecological study of the Great Creek marsh was performed in early 1983 prepL%ratory to the development of the selected flood control plan. . The major wetland units identified are an extensive Phragmites marsh occupying much of the Great Creek area and a series of freshwater wetlands (marsh, swamp, pond, and stream types) along the northern and western boundaries of the park. Phragmites, australis, is the dominant vegetative species throughout the marsh and defines the character of the area. 10 Dr. Karl Eric Tolonen, Final Environmental Report, Great Creek Flood Control Project, Silver Sands State Park, Milford, Connect- icut, Diversified Technologies Corporation, June 1983. Appendix C contains a listing of all the species of vascular vegetation, aquatic organisms and birds identified in the Tolonen study as well as maps of the sampling locations. _19- Though it is not as productive as Spartina in terms of biomass generated, nutrient recycling or habitat value,, it does provide some useful habitat functions. The freshwater wetlands along the northern and western boundaries of the park contain a diversity of wetland plants,, many of them of considerable value to wildlife. Such genera, noted at sampling stations M3-V, M5-V and M6-V (See figure 1 of Appendix C) include Acerr Alnus, Cornus, Elaeagnus, Lindera, Quercus, Rhus, Sambucus, Toxicodendron and Viburnum. Most of the birds usi7n-g-or -917-g-hted in the park (See Table 17 of Appendix C) have been seen in these freshwater areas. Among these is the Northern Harrier or marsh Hawk (Circus cyaneus) which is a rare and endangered species in Connecticut. Three other distinct environments are represented within the marsh. These are the pure Phragmites stands, the open water of Great Creek and a small area of mixosaline nature in the lowest reaches of the creek. The Phragmites stands are almost a complete monoculture with virtually all otfier species having been eliminated. The Phragmites growth is at such a density as to render it nearly impenetrable. The tidal range within the marsh is so small,, approximately 18 inches, that this area is not covered. Under the present conditions, the area will continue to be dominated by this species. Although Phragmites is of limited value to wild- life, during the 1983 ecological survey, a muskrat was seen eating the young stems and leaves of this reed. It also does provide cover for birds and small mammals. The channel of Great Creek serves as both open water envi- ronment and an extension of the saline conditions of Long Island Sound. Sightings of Kingfisher, Mallard, Green Heron and Greater Yellowlegs were made on the park's open bodies of water such as Great Creek. Estuarine species such as horseshoe crab (Limulus Polyphemus) and blue crab (Callinectes sapidus) enter the lower reaches of the creek, usuall7 on the incoming tide. The presence of Spartina alterniflora and other saline dependent species in the mixosaline environment in the lower reaches of Great Creek is an encouraging sign with regard to the restoration. potential of the system. The survival of these species despite the restricted saltwater interchange shows both the ability and the availability of these estuarine species to recolonize any new salt marsh habitat created by increased tidal flushing. In general, the diversity and productivity of the Great Creek marsh is low, especially when compared to local healthy salt marsh systems such as Nells Island which supports a wide range of avian and other species. It appears promising that the Great Creek system can be upgraded in quality and diversity, perhaps to the level it has previously experienced. -20- --Beach and Marine Environment-- Upon leaving the marsh, Great Creek passes beneath East Broadway and crosses a stretch of healthy beach and intertidal sand flats before entering The Gulf. The outlet is the dividing line between the shorefront areas known as Silver Beach and Fort Trumbull Beach, to the west and east, respectively. Silver Beach and Fort Trumbull Beach are wide sandy beaches, heavily used for recreation and generally devoid of any life. Beaches in this area have historically been known to support beach needle grass (Aristada tuberculosa), a state rare species which prefers dry sandy sites along the coast. This species does not currently exist on either of these two beaches and the heavy recreational use makes its future establishment there unlikely. The sand flats in the project area were not sampled specif- ically but can be assumed to contain species commonly associated with this habitat type. Due to substrate instability and to the lack of any large rocks or fixed surfaces, algae, epifaunal, and sessilebenthic species are absent. Species likely in residence here include hardshell, softshell and razor clams (Mercenaria mercenaria, Mya arenaria and Ensis directus,, respectir-yely) and various marine worms, notably polychaetes. The Gulf supports a wide range of finfish, shellfish and crustaceans. Shellfish are harvested both commercially and for. recreation. Quahogs (Mercenaria mercenaria), the most important recreational species, ate taken from both intertidal and subtidal areas in sizes ranging from cherrystone up to four inches. The area is presently closed to recreational shellfishing due to bacterial pollutiont nevertheless clamming does occur. Eastern oyster (Crassostrea virginica) is the important commercial species. Again, due to bacterial pollution, local oyster grounds. are closed to the harvesting of market sized oysters. Seed oysters, however, are removed from these beds for replanting in clean growing areas. Figure 5 shows both the com- mercially leased oyster beds and shellfish concentration areas. The latter, designated by the U.S. Department of Interior, Fed- eral Water Pollution Control Administration in the State of Connecticut Shellfish Atlas (1970) are areas believed to support and produce shellfish of commercial and sport fisheries value. A study of finfish and epifaunal invertebrates iiiThe Gulf was made by Pellegrino and Baker in September of 1979. Speci- men were collected with a 30 foot otter trawl at stations east of Charles Island. A total of 14 finfish species were identified IlPellegrinor P.E. and Baker, J.E. Environmental Monitoring Program of Shellfish Beds Off Charles Island (Milford): Demersal Finfish.Communities, September 1979. UnpuF111-shed. -21- FIGURE 5 LOCATIONS OF LEASED OYSTER BEDS AND SHELLFISH CONCENTRATION AREAS x" % ask ---------- V"t P014 . ................. .. ................ . ........ 4f tj > 41, !04 ol a INN, 0 -I.w ...... ....... 4* .. ...... > eo. At -po As 4h io@ .20 00 4,44 L -f J .10 01P Af .11 Al 00 -ps .10 J114 .10 SCALE IN FEET 0.1 LEGEND: 12,00o' 1.000, 0 2,DO eoukoAmEs OF LEASED OYSTE .R GROUNDS HELLFISH CONCENTRATION ASREA -22- with a like number of bottom dwelling invertebrates. These are listed in table's 4 and 5, respectively. of the finfish, winter flounder (Pseudopleuronectes americanus) accounted for 38.5% of the catch while porgies (Stenotomas chrysops) totalled 38.4%. Winter flounder is an important species for recreational fishing in the Charles Island area. Lady crab (Ovalipes oscellatus) was the most numerous of the epifaunal species collected. Most of the collection area was covered by a sand-shell bottom. Development of Silver Sands State Park Following the destruction of many of the shorefront homes along Silver and Myrtle Beaches by Hurricane Diane in 1955, the state of Connecticut began to buy up much of the coastal property for the eventual purpose of a coastal state park. By 1960t the first master plan for this park had already been formulated. Subsequent plans have been developed for the landfill closure, park roadway system, park drainage and the design of various buildings within the park. Silver Sands State Park will offer 3,000 feet of beach frontage _aric@ 223 acres of parkland with parking capacity for 3,000 cars. Facilities will include, in addition to the beach and parking areas, two concession stands with bathhouses, rest rooms, a boardwalk,, dunes, a park headquarters building, a main- tenance building, and a new access road. The Great Creek wetland will be, left in an undeveloped state to serve as a passive nature study and wildlife area. As the main element of the landfill closure plan, an esti- mated 930,000 cubic yards of fill will be either trucked.on-site, hydraulically placed or some combination of the two. This fill will be used to cap the landfill and to leave a final surface grade suitable for the ultimate development of the state park. Based on the final contours currently envisioned for the landfill closure, approximately 3 13 acres of the landfill will be removed from the Fletchers Creek and Nettleton Avenue channel drainage areas and added to the Great Creek watershed. This represents a 6.7% increase in the existing watershed and the peak discharge rates from the basin. Were it not for the drainage improvements provided by the Great Creek project, this additional runoff would exacerbate the existing flooding problems experienced by the East Broadway neighborhood homes. 12 Goodkind and O'Dea, .Silver Sands State Park, Capitol Project Coordination Study, June 1952, p. 8. 13 As a consequence of the closing of the landfill and the place ment of fill for park development, Fletchers Creek will be filled and eliminated as a separate drainage. -23- Table 4 DEMERSAL FINFISH SPECIES COLLECTED OFF CHARLES ISLAND SEPTEMBER 13, 1979 Average Number Scientific Name Common Name Per 15 Minute Tow Pseudopluronectes ;Kinter flounder 75.0 americanus Scopthalmus Sand Dab 3.0 aquosus Paralichtes dentatus Fluke 1.0 Stenotomus chrysopp Porgy, Scup 78.0 Prionotus evolans Striped Searobin 4.25 Anchoa mitchili Say Anchovy 8.0 Poronotus-tricanthus Butterfish 27.0 Cynoscion regalis Weakfish 2.0 Trinectes maculatua Hogchoker 0.25 Tautogalabrus adsperus Cunner 0.25 Tautoga onitis Blackfish 0.25 Syngnathus fuscus Pipefish 0.25 Mustelis canis Smooth Dogfish 0.25 Centropristes striatus Black Sea Bass 0.25, Average of 4 15 minute tows (from Pellegrino and Baker) -24- Table 5 EPIFAUNAL INVERTEBRATE SPECIES OFF CHARLES ISLAND SEPTEMBER 13,1979 Average Number Scientific Name Common Name Per 15 Minute Tow Ovalipes oscellatus Lady Crab 38.0 Cragnon septemspinosa Sand Shrimp 3.5 Homarus americanus Lobster 2.75 Cancer irroratus Rock Crab 2.0 Libinia emarginata Spider Crab 5.25 Pagurus pollicaris Hermit Crab 0.75 Pagurus longicarpus Hermit Crab 1.5 Limulus polyphemus: Horseshoe Crab 0.5 Neopanope texana Muderab 1.5 Asterias forbesii Starfish 2.5 Busycon canaliculatum Channel Welk 0.75 Loligo pelaei Squid 2.5 Mytilus edulis Blue Mussel 1.25 Astrangia danae Northern Coral 0.75 (from Pellegrino and Baker -25- The timeframe for construction of the Great Creek drainage improvements will precede the closure of the landfill or the commencement of the state park development work. Thus, the construction activities associated with the drainage improvements will have no effect on any development work in or use of the park. Following completion of the Great Creek projectr a width of slightly in excess of eighteen feet of beach at the eastern edge of the state park will be permanently dedicated to use for the creek outlet and, thereby,, lost to recreational use. This represents approximately 0.6% of the total beach length. Offset- ting this loss will be the anticipated improvement in the quality of the marsh which will afford increased opportunities for view- ing wildlife, interpretative uses and other forms of passive recreation. -26- PROPOSED GREAT CREEK FLOOD PROTECTION PLAN Several different strategies were considered and evaluated for their effectiveness in alleviating the drainage and flooding problems at Great Creek. These are discussed in detail in the following section, Analysis of Alternative Flood Control Strate- gies. The various approaches considered included, either indi- vidually or in combination, enlarging and improving the existing Great Creek outlet structure, relocating the outlet channel at one of various locations in or adjacent to Silver Sands State Park, construction of a dike. and pumphouse to protect the East Broadway neighborhood homes from elevated water levels in the marsh, diversion of portions of the upper watershed to neighbor- ing drainage basins and nonstructural solutions such as flood- proofing or acquisition. Following the evaluation of each of these alternatives, the proposed flood protection plan as illustrated in Figure 3 was chosen. The major feature of this plan is the relocation of the outlet from the Great Creek basin to an alignment along and within the eastern boundary of Silver Sands State Park. The outlet structure will consist of a 51 X 161 concrete box culvert capable -of passing a flow of 590 cubic feet per second (cfs). This may be compared to the capacity of the existing outlet which ,begins to produce flooding for any flow exceeding 77 cfs. Self- regulating tide gates and manually operated sluice gates will be set at the inboard end of the box culvert. The existing outlet will be closed and plugged. Each item of the plan is discussed below. Channel Relocation In place of the existing channel Soundward from the conf.lu- ence of the East and West Branches of Great Creek, a new channel will be excavated commencing approximately 1,500 feet up the West Branch from their juncture. This channel wil be 2,340 feet long with an invert elevation of 0.0., NGVD. The first 550 foot segment will be roughly parallel to the existing West Branch channel and will have a width of 30 feet with 2:1 side slopes. At the end of this segment, the West Branch flow is picked up via a 100 foot segment of 30 foot channel thus defining the location of the new confluence of the two branches. From this point, the channel widens out to 40 feet and proceeds generally southerly for most of this 1,790 foot segment, gradually dropping down to elevation -0.8. at the point where it intersects the tide gates and the northern end of the box cul- vert. This point is located approximately 160 feet north of the intersection of the Service Road and East Broadway (see figure 3). -27- one additional segment of new channel will be constructed to bypass the existing confluence and carry the East Branch flows toward the new outlet channel. Six hundred feet of 30 foot channel will be excavated, side slopes again being 2:1, with another 200 feet of 20 foot channel to tie in the drainageway that passes beneath and collects flows from portions of' the watershed east of Surf Avenue. The total length of channel relocated or improved will be 3j,190 linear feet. An estimated 10,000 cubic yards of material will need to be removed to construct the new channel. Borings indicate that this material will be mostly organic in nature, the remains of Phragmites and even Spartina which have accumulated in the marsh. Below this layer are sandy deposits, some of which will also be removed. This material, along with approximately 1,300 cubic yards of additional similar material excavated for the box cul- vert, will be disposed of in the landfill area just to the north of the service road. Box Culvert, Timber Training Walls Flows from the relocated Great Creek channel will leave the marsh and pass under East Broadway via a reinforced concrete box culvert. This box culvert will be 5' X 161 in cross section with an overall length of 315'. The culvert will be laid in a straight line. It will drop 0.2 feet. in elevation over its length with its inlet invert set at -0.8 NGVD and its outlet end at -1.00 NGVD. From the downstream end of the box culvert, two timber training walls will define the sides of an 18 foot wide open channel to Long Island Sound. The walls will be of timber pile and wood sheeting construction, will stand six feet tall, and will extend for 180 feet from the outlet of the box culvert. Both the box culvert and the open channel will be entirely on State property adjacent to the property boundary. Costs for these two components are estimated (1983) at $172,800 for the box culvert including excavation, installation, backfill and road restoration and $79,500 for the timber training walls. Control Structures The control structures will be located in a precast concrete vault, 5016" long by 321 wide, located at the upstream end of the box culvert. Two 4 1/2 ft. by 6 ft. tide gates and two sluice gates of the same size.will be mounted in series in this vault to regulate incoming tidal flows. In addition four 2 1/2 ft. by 2 1/2 ft. , flapper gates will be mounted parallel. with the tide gate, one on either side of each gate, to augment discharge capacity under peak flow conditions. -28- The tide gates will be the primary control on tidal flows. The function of a tide gate is normally to block or limit incom- ing tidal flows while allowing for the normal discharges from the coastal pond, marsh or embayment to occur at low tide as soon as the head behind (inboard of) the tide gate exceeds the water level outside. Standard tide gates eliminate the tidal flushing action necessary for the maintenance of salt marsh vegetation by preventing the interchange of saltwater and freshwater during incoming tides. For Great Creek, the tide gates being proposed for installa- tion are non-standard in that they may be adjusted (over a four foot range) to allow for a wide range of rates of tidal inflow and exchange. This design of tide gate, known as a self- regulating tide gate, is a recent innovation. Its chief advan- tage over conventional gates is to allow for the maintenance of salt marsh vegetation and characteristics or, in cases where restricted circulation has previously eliminated characteristic salt marsh vegetation, to allow for its restoration. An example of an apparently successful salt marsh restoration using self- regulating gates can be seen at Pine Creek in Fairfield where they were installed three years ago. For more information on self-regulating tide gates, see Appendix A. Although the self-regulating tide gates are very simple in design and have operated very reliably to date, they are a fairly new development.. Therefore, the manually-operated rectangular sluice gates will be installed as a redundancy in the event that any problems develop with the tide gates. Each sluice gate will be 72" wide by 5411 high. Under normal operating conditions, they will be set full open to allow tidal inflow to be regulated by the tide gates, I f the tide gates should need maintenance or repair work, the sluice gates can then be adjusted to limit incoming flows. The sluice gates will also yield an added benefit in channel maintenance should sediment build up in the culvert or open channel or should routine channel cleaning be desired on a regu- lar basis. This could be accomplished by closing the sluice gates at high tide just as outflow from the marsh begins. when the tide has fallen to its low point in Long island Sound, and therefore the available head is at its maximum, the sluice gates would be opened. The resulting surge of water released from the marsh . at maximum head would flush any accumulated downstream sediment from the culvert or the open channel. Closure of Existing Outlet Channel upon completion of this project, Great Creek will enter Long Island Sound via a new channel 1,800 feet west of the existing outlet. Consideration was given to retaining the existing outlet and allowing it to function in tandem with the proposed new outlet channel. This option was discarded for two reasons. -29- CONTENTS PAGE NO. RELATED DOCUMENTS iii LIST OF TABLES iv LIST OF FIGURES v INTRODUCTION 1 HABITATS EXAMINED 3 Marshes 4 Swamps 4 Submersed Grassbeds 5 METHODOLOGY 5 Photo Sources 5 Photo Interpretation and Field Verification 5 Map Preparation 6 Area Measurements 6 Limitations 6 FINDINGS 8 Forested Wetlands - Swamps 8 Bay Forest (Atlas Type VI) 8 Alluvial Swamp (Type X) 10 Moist Pine Forest (Type IV) 11 Moist Pine Savannah, Bog (Type V) 11 Geographic Distribution of Forested Wetlands 12 Emergent Wetlands - Marshes 13 Freshwater Marshes (Type III) 13 A. Low Marsh 13 B. High Marsh 14 Geographic Distribution of Freshwater Marshes. 15 Submersed Grassbeds 15 Geographic Distribution of Grassbed's 34 Advantages of Selected Flood Control Plan The selected option is the least costly of all the plans evaluated for protecting the homes in the lower Great Creek basin from flooding damage. As can be seen in the following section of this report, Analysis of Alternative Flood Control Strategies, the chosen scheme also possesses several other advantages com- pared to some or all of these alternatives. Construction will take place totally within the boundaries of State property. This will minimize the need for both con- struction and maintenance easements. It also avoids the taking of residential properties, a factor which boosted the cost of some of the other alternatives. Other advantages of the selected plan, discussed in more detail later, include no constraint on the width of the dis 'charge channel, thus allowing more efficient drainage from the marsh, and no automated components. The latter feature means lower maintenance costs since no testing, servicing or repairing of pumps or other equipment is required. One final benefit of the chosen alternative is the avoidance of the use of diking. Several of the alternatives considered Anvolved the construction of up to one mile of dike. By circum venting the need for such a structure, the construction and maintenance costs associated with the dike were eliminated. This non-dike alternative is also much less land consumptive and avoids the creation of an attractive nuisance. Construction of Improvements Construction of the drainage improvements herein described is anticipated to require six months. The preferred interval is late spring, beginning in late May or June after the heaviest rains, and extending through to autumn. Drier weather condi- tions will expedite the work process. The initial phase of work will involve excavation for the new outlet channel. During this phase, the inland portions of ,the channel will be excavated but not connected to Long Island Sound. Ten thousand cubic yards will be removed during this work. This material will probably be disposed of within the Milford Landfill in an area immediately northwest of the inter- section of the park service road and Samuel Smith Lane. Excavation of the trench for the box culvert will be the second phase. This would commence with the removal of 3,000 cubic yards of material to form the trench for the culvert. A gravel base would be laid, graded to proper elevations and com- pacted to provide a base which would not be subject to settling or shifting. The culvert comes in eight foot sections which are individually lowered into place by a small crane. The sections -31- have an interlocking lip design and a bituminous sealer is ap- plied at the joints. Following the placement of the culvert sections, 1,700 cubic yards of backfill will be used to close the trench back to grade. The remaining 1,300 cubic yards of spoils will be landfilled with the channel spoils. . During culvert installation, East Broadway will probably be closed to traffic at the eastern boundary of the state park. Another option may be to install one half of the culvert at a time while traffic is maintained on the opposite lane of East Broadway. The practicality of this will be assessed at the time of construction. Installation of the culvert and, therefore, the closing of East Broadway would take a maximum of one week. The vault which will house the tide gates and sluice gates will be installed at the same time as the box culvert. The same work elements are involved. The inboard end of the culvert trench will be deepened to f orm a pit. A gravel base is laid onto which the precast conc -rete vault is lowered by crane. The gates are then installed in the vault and a steel grate is placed over them and locked. The tide gates will be placed at the upstream end of the vault with the sluice gates to the Soundward end. Construction of the training walls is an independent element which may be undertaken at any time during the construction sequence. Closure of the existing outlet would be the final element of the project. The elements involved in this phase are contained in the previous discussion of closure. If the channel north of East Broadway toward the existing confluence is filled to grade, an estimated 1,000 cubic yards of fill would be required. The requirement for construction easements will not be determined until final design. Additional easementsy if neces- sary, will likely be minimal. The new outlet and relocated channel will be located totally within State property. Depending on the proximity of the culvert and open channel to the private property boundary, some minor width of construction easement may be sought to facilitate equipment operation. At the existing outlet, a 12 foot maintenance easement was previously established to allow for necessary cleaning and repair of the outlet pipe and channel. Use of this easement to remove pipe sections and fill the channel is planned. Additional easement width will be ac- quired if necessary. Maintenance of the completed project will consist of ser- vicing and adjusting the tide and sluice gates, maintenance of channel slopesr mowing grass that will be used to stabilize portions of the channel slopes, and clearing the gates, culvert and channel of any debris or sediment which may accumulate there- in. It is not anticipated that any permanent maintenance ease- ments will be needed to perform these tasks. -32- ANALYSIS OF ALTERNATIVE FLOOD CONTROL STRATEGIES Before arriving at the solution described in the preceding section, numerous alternative strategies and combinations of measures were considered to alleviate flooding in the Great Creek Basin. These involved improvements to the existing outlet, upstream channel improvements, construction of a new outlet and a relocated creek channel, diversion of a portion of the surface flow entering the Great Creek Basin, floodproofing of affected homes, acquisition of affected homes and properties and the extension of the existing outlet beyond the intertidal zone. Each of these possible solutions, together with the "no action" alternative, will be discussed in this section. Improvements to Existing Outlet Because the present flooding problems along East Broadway and adjoining streets are caused primarily by the inadequacies of the existing outlet structure, increasing the capacity of this outlet was the first remedial step to be evaluated. This was considered both as a freestanding action and as an element in a larger project. Enlargement of the existing outlet as a freestanding action was analyzed and found to be unable to remedy the drainage prob- lems at Great Creek. Because of the proximity-of residential structures abutting the existing outlet, channel width is limited to twelve feet unless some of these properties are acquired. This width of channel is insufficient to handle the design flows. In addition, if the opening of the channel is increased without providing some form of tidal flow control structures, the fre- quency and severity of tidal flooding in the basin could be increased. For these reasons, improvements to the existing outlet were dismissed as an alternative unless combined with other protective measures. Another plan which would use the existing outlet and which was considered in greater detail contained many of the elements of the proposed project. Under this plan, the flow of Great Creek would be intercepted just west of the existing confluence of the two branches and would be conveyed to and under East Broadway by 715 feet of 41 x 121 box culvert. Approximately 850 feet of new stream channel would need to be constructed to relo- cate the confluence to the head of the culvert alignment. By passing through several residential properties on a direct route to the sound, the new culvert alignment avoids the circuitous route the lower creek now uses. This, however, requires the acquisition of all or portions of several properties and the removal of three structures including two homes, increasing both neighborhood impact and project cost. -33- Control of tidal flows in this system is accomplished via a tide gate-sluice gate arrangement similar to that contained in the proposed project. A vault structure would be built into the northern end of the box culvert to house the gates. Extending from the soundward end of the box culvert, two timber pile and wood sheet training walls would confine the outlet channel until it reaches elevation -1.00. This section of open channel mea- sures 180 feet in length and 15 feet in width. The estimated cost of the above system is $754,300 (1983). This plan was judged to be less desirable than the proposed plan due to the necessary property acquisitions, the estimated cost being 50% above that of the proposed action and the lack of any offsetting advantage in efficiency as compared to the proposed project. A third scheme includes all the elements of the above, except the sluice gates, but incorporates a 5,,250 foot dike around the southern and eastern perimeter of the marsh. The dike would average four feet in height with 1:4 side slopes and a ten foot top width. The dike provides an extra measure of protection in larger flooding events by containing flood waters in the marsh rather than allowing them to spread onto the lower elevations of the roads and yards at the northern ends of the affected side streets. It also requires a mechanism to drain the water which will collect on its southern side resulting from the collection of drainage in the 47 1/2 acres between East Broadway and the dike. For this purpose, a pumping station capable of handling 73 cfs is proposed just south of the dike on Blair Street. The construction of the dike gives extra protection from inland flood flows but, as with the situation caused by runoff from the residential area collecting south of the dike, coastally produced runoff could also be impounded by the dike and prevented from draining into the marsh, producing a 'bathtub effect' on its south side. This could arise in storms, such as that of March 29, 1984, where storm-driven water from the Sound flows over East Broadway. To alleviate this problem, a drawdown facility con- sisting of a 121 x 41 box culvert through the dike and three 42" x 42" sluice gates is envisioned at the end of Silver Street to drain this water to the marsh. The addition of diking adds several major costs to the project. These include (1983 estimates) $135,500 for the dike, $374,800 for the pump station and $63r5OO for the drawdown facil- ity. With these costs, the total estimate for this alternative is $1,232,100. Although under certain conditionst the diking does provide an extra measure of protection,, this alternative and another diking alternative to be considered next possess a number of undesirable features. Cost is a major drawback. Another is reliability. The pumps must be, maintained, repaired and peri- odically tested. This involves extra labor and a consistent -34- maintenance effort. Even then, the possibility of malfunction always exists with any mechanical device. The non-dike alterna- tives rely exclusively on gravity, a much more dependable power source. The dike alternative just described again requires the acquisition and demolition of three structures. For reasons of cost effectiveness, reliability, ease of maintenance and acquisi- tion requirements, the diking alternative was deemed less Practi- cal than the selected option. Drainage Improvements Using Westerly Outlet With Diking A fourth strategy which was evaluated in some detail con- sists of a combination of the proposed project and the diking alternative just described. The channel relocation, box culvert, tide and sluice gates and timber-lined open outlet channel would be exactly as proposed in the project description section. In addition to these improvements, the same 5,250 foot dike and the pump station and drawdown facility just'described would function as outlined for the existing outlet option. Because relocating the marsh outlet to the park's eastern boundary (as proposed) is less expensive than retrofitting the existing outlet, the west- erly outlet dike alternative is also less expensive than the first diking proposal. Those cost savings for'the western out- let, either with or without the dike, arise due to a shorter length of box culvert (310 feet vs. 715 feet) necessary to the west and the avoidance of property acquisition costs since the westerly alignment is totally within state-owned land. Outlet- ting Great Creek at the westerly location in combination with the dike, pumphouse and drawdown facility is estimated (1983) at $979,100. Diversion Diversion of flow from some portions of the Great Creek basin to neighboring watersheds was analyzed in some detail to see whether the flows could be reduced sufficiently to allow cuts in the scale and cost of the Great Creek drainage improvements. Five sub-basins, shown in Figure 6, were identified from which such diversions could be accomplished. one sub-basin of 45.8 acres was delineated in the northern portion of the West Branch basin. Flow from this area could be intercepted at Pilgrim Lane and Carlson Drive and conveyed via 1,410 feet of 42" and 48" RCP to the landfill drainage system, from which it would ultimately be emptied into the Nettletown Avenue Creek. Under design storm conditions, 95 cfs could be diverted from Great Creek via this connection. Four areas totalling 67.5 acres were judged feasible for diversion from the East Branch watershed. Flow from these areas would be directed eastward and drain into Milford Harbor. -35- DIVERSIONS FROM GREAT CREEK WATERSHED FIGURE 6 AVE UE 2 ---------- P ME GULF LEGEND West Branch Watershed East Branch Watershed ftposed Watershed Diversons 45B Drainage Area in Acres o963) Drainage Area less Diversions Existing Pipe Proposed Pipe -36- The raw acreage removed from each watershed as well as the percentage of the watershed area, the percentage reduction of design flow and the cost of the proposed diversions are shown below. Flow Diversions from Great Creek Basin Acres of Watershed of Flow Removed Area Reduction Reduction Cost West Branch 45.8 19 22 $100tooo East Branch 67.5 23 20, 350,000 Total Watershed 113.3 21 19 450,000 Note that the aggregate percentage flow reduction is less than that for either branch individually because of the 36 minute gap in times of concentration between the two sub-basins. While the peak flows for each branch are reduced by 20-22%, these reduced peak flows do not coincide timewise. Therefore, the combined peak flow reduction is less than the reductions achieved in the individual basins. Despite the apparent significance of a near 20% reduction of total peak discharge, the effect on flooding levels experienced in the basin is minimal. A 20% reduction in the 100 year peak flow of 590 cfs yields 472 cfs, precisely the discharge associ- ated with the 25 year storm. Flood stages associated with the 25 year storm are 4.85 feet to 5.35 feet versus a tidal head of 3.5 feet or 4.2 feet respectively. For the 100 year event, the flood stage is 5.14 feet against mean high tide (3.5 feet) or 5.60 feet against mean spring high tide (4.2 feet). Thus, the reductions in flood stage experienced in the basin are .25 to .3 feet or 3-4 inches. As a freestanding solution, the $450,000 cost of the diversions can not be justified against these reductions. When considered as a component of the proposed plan, a much greater level of protection which includes the increment achievable via diversion can be realized for the estimated project cost of $501,300. The diversions, therefore, are not seen as the most cost effective available solution either as a freestanding pro- ject or in combination with the proposed plan. Floodproofing Floodproofing dwellings involves employing various practices to prevent the entry of waters into the structure. . The most common measures are sealing openings such as basement windows and doors, earthen berming around the structures to seal out stand- ing water, or jacking the structures up above the flood elevation. For the homes of the Great Creek neighborhood, berming is not practical due to the extreme density and small lot size of -37- the dwellings. Given the number of affected structures, jacking would be cost prohibitive. Sealing of basement and/or lower floor openings such as doors, windows and hatchways was consid- ered as a possible alternative and reviewed*as to cost. As shown in Table 1, 127 homes are within the five foot contour elevation. Another 41 homes lie partially within this boundary for a total of 168 homes completely or partially built on ground below elevation 5.0 feet. This elevation was selected as the cutoff point for installing floodproofing measures. Neither an actual count of the number of lower level build- ing openings nor an inventory of the number of affected struc- tures with partial basements was made. Floodproofing costs are based on an average gf six openings per house at a sealing cost of $300 per opening and a contingency, overhead and profit allow- ance of 30%. This produces a cost figure of $2,500 per house or $420,000 for the 168 lowermost dwellings. The cost of the floodproofing option is not unreasonable when considered as a solution to the conditions experienced at Great Creek. This alternative is' at a competitive disadvantage, however, when evaluated against the proposed plan in three re- gards. First, floodproofing yields protection only to the homes actually treated while the drainage improvements provide relief for all homes in the basin. Secondly, while the drainage im- provements will remedy inundation of homes, yards and streets, floodproofing protects only the former. Emergency access to homes on flooded roads as well as the level of general inconven- ience for homeowners is not improved by floodproofing. Lastly, floodproofing has a greater impact on the use and enjoyment of the dwellings, both during and after construction. No alteration of the homes is involved with the proposed plan. For these reasonsr the proposed plan is seen to offer superior protection compared to floodproofing these homes. Acquisition of Affected Properties The purchase of some of the more frequently flooded homes would eliminate the most severe impacts of the drainage problems at Great Creek. Properties acquired could be incorporated into the State holdings at Silver Sands State Park. Residents who are relocated would receive a very high degree of flooding protection unless, of course, they were to relocate into another floodprone area. Those residents who remain, presumably those less affected by flooding, would have to continue to deal with. the level of inconvenience experienced in the past.unless additional measures such as floodproofing remaining homes were added to the project. Acquisition as a solution would avoid construction in the wetlands as well as construction impacts on the beach and at the East Broadway crossing. However, the beneficial impacts associ- ated with marsh restoration would also be foregone because tidal -38- flushing would not be improved. Although the construction im- pacts associated with the proposed project would not occur, the neighborhood would experience other construction impacts in connection with the demolition ofthe acquired structures. Cost factors render the acquisition alternative infeasible. Acquisition of even 100 homes would cost several million dollars. In addition to buying the properties, demolition of the struc- tures and perhaps relocation services for residents would repre- sent other costs. It is likely that not all the homeowners involved would be willing sellers, so that additional legal expenses could also be involved. This alternative is not con- sidered a viable option as a flood control plan. Culvert Extension A previous effort to find a solution to the flooding prob- lems at Great Creek was made in 1974 when C.E. Maguire, Inc. was commissioned to, do a drainage study. Their study resulted in a recommendation to make several modifications to the exis@ing outlet in order to increase its hydraulic efficiency and to reduce maintenance problems. The major feature of the C.E. Maguire plan was a 600 foot extension of the outlet pipe into Long Island Sound. The.exten- sion would use 48" corrugated metal pipe encased in riprap armor. The outlet end of the pipe would be elevated 1 foot 6 inches off the Sound bottom to prevent sediment infiltration or blockage. To increase hydraulic efficiency, the existing tide gate, which has deteriorated to a non-functional condition, would be removed and a smoother transition would be constructed between the box culvert and the pipe to reduce friction losses. Control of incoming tidal flows would be provided by the high friction losses at the rough lip of the metal pipe which would restrict average tidal inflow to 1,300,000 cubic feet. No additional control mechanism would be provided. The estimated cost of this construction was $125,000 (1974). The C.E. Maguire recommendations were not implemented be- cause of several concerns and unanswered questions in connection with this plan. Among these were concerns that the impervious armor around the pipe would disrupt littoral transport and could alter surrounding private beaches. The pipe extension was thought to be a potential hazard to boaters because it would be partially submerged at high tide. Cleaning of such a long sec- tion of pipe if it did become clogged, potential safety hazards to swimmers, and the lack of tidal flooding protection for Great Creek if inflows were greater than anticipated were other ques- tions which led to the DTC study to find a new solution. -39- No Action Alternative One final course of action would be to allow the existing conditions at Great Creek to continue. This "no action" alterna- tive would avoid all construction impacts. In addition, it offers the lowest capital cost, saving $501,300 compared to the recommended plan. There are, however, other real costs- -connected to this option. They occur in the forms of continued social disruption caused by future flooding and of foregone benefits which would have arisen from an improvement of the existing conditions. The foregone benefits include not only protection from flooding but increased property values once this flood threat is reduced and the likely property improvements that homeowners would make in the safer environment. The savings as Town forces are relieved from the task of the periodic cleaning of the existing outlet would also be forfeited. Also, as increased tidal flushing restores the marsh to a healthy saltmarsh system, the Phragmites related fire hazards would be reduced, aesthetics improved and mosquito breeding curtailed. These benefits would also be lost. Further, non-implementation of the Great Creek drainage improvements would presumably not prevent the closure of the Milford landfill or the development of Silver Sands State Park from proceeding. Each of these actions will operate to increase the severity of localized flooding if no compensating improve- ments are made. The landfill closure will add 34 acres of water- shed and runoff to Great Creek while the park development, plans call for a new east-west service road along the northern perime- ter of the marsh. The service road will consume some of the runoff storage volume currently available in the marsh as well as creating additional impervious surface replacing existing natural ground. In light of these.upcoming developmentsg, the "no action" alternative actually represents a deterioration from the present conditions rather than a continuation at current flooding levels. -40- PROJECT IMPACTS As is the case with all construction activity, this project will result in temporary impacts during construction operations and permanent impacts associated with the structures erected. The short-term impacts, largely adverse, and measures employed to mitigate them are discussed below followed by a description of long-term impacts, largely beneficial. ConstructionImpacts The principal short-term impact, based upon potential effect on the natural environment, is increased erosion and sedimenta- tion resulting from disturbing soils to create the new channel for the relocated Great Creek. Impacts will be felt within the Great Creek marsh and adjacent nearshore areas of Long Island Sound. Because of the potential adverse impact to nearby shellfish resources (concentration areas shown in Figure 5), the sedimenta- tion resulting from the construction of the new outlet is con- sidered the most important impact to control. In order to mini- mize sedimentation from this source, all excavation work inland of the proposed culvert will be completed and the sediments allowed to more or less stabilize before the channel across the beach is begun. It is not feasible to attempt to further contain the materials disturbed during the construction of the relocated creek channel. Upon the connection of the new channel to the Sound, a short term pulse loading of disturbed sediments and organic debris will be flushed from the marsh as the reintroduced tidal exchange suspends some of the material disturbed by construction. The organic component of this cleansing will be quickly degraded, while the. mineral fraction will settle out in The Gulf. The latter is not of sufficient volume to cause the burial of resi- dent shellf ish. In any event, the DEP imposed prohibition on construction and dredging during the shellfish spawning season from June 1 to September 30 will be observed for the protection of oysters and other resident shellfish species. Final connec- tion of the new channel will be consummated after this date. Sedimentation from the channel work across the open beach area will be minimal given the small affected area and the coarse-grained material found there. Also, the marsh, in per- forming its natural function as a sediment sink, will trap sedi- ments transported into it by the incoming tidal flows. Although a major emphasis of this project is the restoration and upgrading of the Great Creek wetlands, it must be recognized that certain negative wetland impacts must necessarily be incur- red in accomplishing this goal. Some wetland area will be -41- incorporated into the new channel. In the short term, additional areas will be impacted during construction as temporary access roads are created using fill, beams, or corduroy mats for support of construction equipment. Any such materials will be removed upon the completion of the work. These temporary impacts will be offset by a substantial permanent upgrading of the marsh system. ..Storage of equipment or the stockpiling of construction materials will not be allowed within wetland areas. All exposed non-wetland areas will be seeded and vegetated to foster rapid stabilization. Disturbed wetland areas will be allowed to na- turally revegetate so as to induce the introduction of more favorable salt marsh vegetation. Progress will be monitored, so if exposed areas present a problem, some corrective action can be taken. Additional control measures deemed necessary by regula- tory agencies can be incorporated during the permitting process by the Army Corps of Engineers or the DEP Water Resources Unit. Impacts to air quality will result from the burning of fuels by construction equipment and the potential of releasing airborne particulates through construction activity. Gasoline powered engines emit carbon monoxide and hydrocarbons as their principal pollutantsp while diesel engines emit more nitrogen oxides and particulates. The scale and duration of equipment use will not result in a significant elevation above background levels for such pollutants in the highly urbanized corridor stretching from New York to New Haven. Many construction projects have a high potential to increase local levels of particulates through the entrainment of fugitive dust in the air column by the action of wind currents across disturbed areas. For this project, the preponderance of dis- turbed land will be wetland soils of the marsh with little re- sultant potential to generate fugitive dust. when appropriate in drier areas, as in thecrossing of East Broadway for exampler or during trucking of excavated material, necessary control measures will be employed by the contractor to minimize fugitive dust problems. These include application of dust control agents such as calcium chloride to disturbed areas and tarpaulin covering of loaded truck beds. Other construction impacts, namely the disruption of East Broadway traffic, increased noise levels and the general disturb- ance to the residential neighborhood, will temporarily affect only those people who will also receive the greatest benefit from the project, the residents of the Silver Beach area. The con- struction period is expected to last six months. The following measures will be employed to minimize these impacts. During installation of the box culvert under East Broadway, two-way traffic will be obstructed. However, one travel lane for alternating use by traffic in either direction will be kept open, if at all possible, so as to maintain the utility of this road- way. if, during final design, it is determined that installation -42- techniques require total closure of the road, traffic disruption will last about one week. Typical levels of noise generated by various kinds of con- struction equipment are graphically displayed in Figure 7. The greatest noise levels will result from impact equipment, such as pile drivers used during erection of the training walls and jack hammers used during construction under East Broadway. Residents at the western end of East Broadway will be most affected by these activities. Construction noise is specifically exempted by regulations promulgated by the Department of Environmental Protection to control noise (Section 22a-69-1.8(g) Regulations of Connecticut State Agencies) . In order to mitigate potential impacts, con- struction activity will be limited to daytime hours. Also, the contractor will be allowed to use only properly muffled internal combustion engines. Although virtually all of the construction activity is on State property, the accustomed day-to-day neighborhood atmosphere will be temporarily disrupted. Construction vehicles will trav- erse local roads and be operated immediately adjacent to private property in many areas. Any operation of construction equipment on private property will require a construction easement. The maintenance easement along the existing route of Great Creek south of East Broadway will be used during plugging of the old culvert. Additional easements may be needed to fill the old channel north of East Broadway and where the rerouted channel is closest to private property. Construction will not impact any rare or endangered species of flora or fauna. The Natural Diversity Data Base maintained by the DEP Natural Resources Center lists only one species in the general area of the project: historic records of a rare grass. Beach Needlegrass (Aristida tuberculosa) had been known to exist along sandy beaches in the. area,, but has not been observed re- cently. The two small segments of beach to be disturbed by con- struction activity are presently heavily trafficked and are not inhabited by this species. This document will be reviewed by the Connecticut Historical Commission to assess any potential impact to archaeological or historical resources. The recommendations of the State Historic Preservation Officer (e.g. conducting an archaeological survey) will be implemented as the project proceeds. Because the relocated channel is confined to the border area of the state park, the project will not adversely impact future plans to develop an intensive saltwater swimming facility. In fact, as it is sized to accept runoff from portions of the park, it is a prerequisite to future development. Excavation for the channel will not disturb any areas previously used for landfill. -43- tree (Liriodendron tulipifera) may also occur there. White cedar (Chamae- cyparis thyoides) becomes increasingly more common in swamps along upper reaches of streams. Few plants grow under the dense shade of those trees; among these are such shrubs as Virginia willow (Itea virginica), star anise (Illicium floridanum), and fetterbush (Leucothoe axillaris). Netted chain fern (Woodwardia areolata) and cinnamon fern (Osmunda cinnamomea) are among the few shade tolerant herbs growing there. The more open borders of these swampy woods may be covered by dense thickets of swamp cyrilla (Cyrilla racemiflora), black titi (Cliftonia. monophylla), and large gallberry (Ilex coriacea). Wax myrtle (Myrica cerifera) and yaupon (Ilex vomitoria) also grow in this habitat and are especially common along brackish waters. The transition zone between these forested wetlands and upland pine-oak forests may support growth of plants adapted to somewhat better drained condition such as water oak (Quercus nigra), laurel oak (Q. laurifolia), sweetgum (Liquidambar styraciflua), southern magnolia (Magnolia grandiflora), and devilwood (Osmanthus americana). Alluvial Swamps (Type X) Areas of low relief, subjected to only short periods of seasonal innundation may support amixture of relatively flood tolerant species including swamp tupelo (Nyssa sylvatica var. biflora), red maple (Acer rubrum var. rubrum and var. drummondii), green ash (Fraxinus pennsylvanica ), pumpkin ash (F. profunda), swamp cottonwood (Populus heterophylla) and overcup oak (Quercul lyrata) as well as the extremely flood tolerant bald cypress (Taxodium distichum) and water tupelo (Nyssa aquatica). 10 DiS20sal Impacts Because the amount of excavation greatly exceeds the amount of filling in this project, it is anticipated that approximately 11,000 cubic yards of excess material will remain and require disposal. This material can be characterized as being saturated sandy soils with a high proportion of organic content, much of it decomposing. A preliminary disposal site has been identified and is depicted in Figure 8. This area, northwest of the intersection of the Service Road and Samuel Smith Lane is totally within the state park and has been previously filled during landfill opera- tions. it is identified in the 1978 Landfill Closing Plan by Fuss and O'Neill as being underlain by burned dump residue. Preliminary plans for the development of the state park have included this section as an area of minimal development as it is slated for overflow parking and passive recreation. Being previously disturbed, this area supports vegetation typical of such sites including Phragmitesf staghorn sumac, grey birch and bayberry. The area outlined in Figure 8 is over 40fOOO square yards (or approximately nine acres) so that, if uniformly spread, the disposed material would be less than one foot in depth. Final grades will slope toward both roads and should be within the final grades recommended for development of the park. Long-Term Impacts The most important long-term impact,, the purpose of the project, will be to provide an increased measure of flood protec- tion to the existing residences. The project will result in increased drainage of the Great Creek system and thus some relief from flooding caused by precipitation. The tide gates will provide protection against coastal flooding during smaller storms but cannot prevent storm tides from overtopping East Broadway during major storm events. In all cases, the duration of flood- ing will be reduced to the length of one tidal cycle, whereas it now can last up to f ive days. Quantification of the degree of protection afforded by the project can be found in the discus- sion of Costs and Benefits. An extremely important side effect of the proposed drainage improvements will be the benefits to the environment that result as the increased tidal flushing promotes restoration of the Great Creek marsh. The following description of a characteristic salt marsh is taken from the Pre-Design Report by Diversified Technol- ogies Corporation. Restoration would be expected to produce a characterlis- tic estuarine community. Elevation is a good predictor of the specific organisms expected to be present. -45- LOCATiON OF PROPOSED DISPOSAL AREA M-WRE 8 0 2wft. ShredcW C&"PWK N SWOOP Pkint Milford 2t Landf ill 12-,- Alllli@ " -d n SIM* RINI Arl P- -46- Below 0. 0 feet MSL the environment would consist of either mudflats or tidal streams. The dominant plants would be various species of algae (seaweeds). Major benthic organisms would include oysters, several spe- cies of clams and mussels, crabs, and polychaete worms. A variety of fish, shrimp, and blue crabs would swim in the tidal waters. Ducks, geese, gulls, terns.. sand- pipers and other aquatic habitat birds would utilize both open water and mudflat areas. From 0.0 feet up to about mean high tide (ca. 3 1/2 feet) would occur an intertidal marsh dominated by Spartina alterniflora. Ribbed mussels, crabs, bar- nacles and other invertebrates would live among the roots and stems. Birds such as the Clapper Rail use the intertidal marsh. From mean high tide to mean s2ring high water would occur a high marsh community with a variety of species of plants, commonly including Spartina patens and Distichlis spicata. Birds and other animals are sim- Tl-arly diverse. Above mean spring water occurs a transition to fresh- water communities, which may contain Phragmites, or to upland communities. The high marsh is flooded only a few times each month by sea water, whereas the inter- tidal marsh is covered and uncovered twice each tidal day. The entire complex has high biological produc- tivity, supports a diverse community and produces several speciff of potential economic or recreational value to man. The benefits of combining salt marsh restoration and flood control are many. The successful restoration of the salt marsh, which will require several years to a decade, will re-establish a biologically productive marsh, restore the wildlife value of the area and provide for recreational opportunities such as fishing, crabbing, bird watching and nature study. The diversity of wildlife found in a healthy Spartina dominated marsh is not found in the existing Phragmites marsh. Marsh fires, started accidentally or deliberately, burn vigorously in dried Phragmites, presenting a significant hazard to adjacent property owners ana users of the area. Healthy salt marsh vegetation dominated by Spartina does not present such a .hazard. 14 Diversified Technologies Corp., Pre-Design Report, Flood Control-Great Creek? Silver Sands State Park, Milford, CT, 1983, 2 -8. _47- A well managed salt marsh would have a significantly lower potential for promoting the breeding of mosquitoes as stagnation is eliminated. Similarly, odor problems would be reduced. Restoration of a natural marsh will also provide pleasing new vistas to visitors at the state park and to local residents. One indirect effect of improving the marsh area will be a rise in property values in surrounding neighborhoods (in addition to that resulting from flood relief). An historic perspective on the degradation of the Great Creek marsh is'presented in Appendix B. There will be permanent impacts to the existing sandy beach as a result of construction of timber training walls to contain the open channel. The 1801 long, 181 wide walled channel will occupy 360 square yards of sandy beach at the eastern border of Silver Sands State Park. Although the relative scarcity of publicly-owned sandy beach in Connecticut makes this a valuable recreational resourcei, this loss.is considered negligible. Only 18 of 3,000 linear feet, or 0.6%, of the state-owned shorefront will be forfeited. Moreover, the entire 4.5 mile stretch from Milford Harbor to Milford Point is predominantly sandy. Also, the drainage improvement project is a prerequisite for eventual development of Silver Sands as an intensive saltwater swimming facility. The training walls will also impact littoral transport phenomena which redistribute sand along this stretch of coast. in general,, sand- transport in this area tends to result in net east-to-west movement. The training walls will obstruct this flow, resulting in a build-up of sand on their east side and a reduction of beach nourishment for areas immediately to the west. Because the tombolo connected to Charles Island, approximately 800 feet to the west, acts very effectively in a similar mannerr only the intervening stretch, of beach will be affected. This area is presently the widest, most sandy section of beach in the area and, with the tombolo and training walls acting as terminal groins at either end, should remain stable. Any additional artificial sand nourishment which may be needed to develop the state park for swimming will receive an added measure of protec- tion due to the presence of the walls. Littoral sand transport is not expected to block the channel entrance since the structure will extend seaward to -1.01 NGVD to attenuate potential impacts. The channel is also sized so that velocities for normal incoming tides will not be sufficient to carry sand up the channel (mean spring high tide velocity = 3.55 feet/second). Erecting this structure across open beach will have attend- ant aesthetic effects. The wall will rise 6 feet above the existing grade as a maximum at its seaward end tapering to one foot at its landward end as the beach slopes up along its length. It will be very similar in appearance to the training walls which protect the outlet at the end of Nettleton Avenue at the opposite -48- end of the state park. Although there will be some visual im- pact, it will be but one of several structures perpendicular to the shore in the area and will serve as a visual partition be- tween the private residences and beach to the east and the public beach to the west. However, the right to public access below mean high water will not be unreasonably impaired since the structure will extend only to elevation -1.01 while low tide elevation is at elevation -3.51 thus permitting passage around the seaward end. -49- PUBLIC PARTICIPATION The public has been involved in the development and selec- tion of the proposed flood protection project. Both municipal officials and local residents have been consulted during the planning stages. Additional input will be obtained through review of this document and during the permitting process. The major forum for public participation was an informa- tional -meeting held on September 21,, 1983 in Milford. (See Appendix F) Various alternate plans, as detailed in the section Analysis of Alternative Flood Control Strategies, were explained to local citizens. The general consensus of the meeting was to .proceed with the proposed plan of the relocated channel. Slight revisions to the plan suggested at this session were considered during subsequent design. Previously, town officials from the Engineering Department and the Flood and Erosion Control Board had reviewed preliminary designs. All comments received during review of this document, which will be distributed to municipal officials, the Silver Sands Association and any person requesting it, will be considered before project implementation. Another opportunity for comment will be during any public hearings and public notice periods required for the various permits. _50- PERMITS AND APPROVALS This project will require a number of permits from Federal and State regulatory agencies. The applicant in each case will be the Department of Environmental Protection,, Water Resources Unit, Flood Management Section. Required permits are: - Inland Wetlands Permit (pursuant to section 22a-42 Connecticut General Statutes) from DEP, Water Re- sources Unit, Wetlands Management Section. - Structures Permit (pursuant to section 22a-361 Con- necticut General Statutes) from DEP, Water Resources Unit, Wetlands Management Section. - Diversion Permit (pursuant to section 22a-368 Con- necticut General Statutes) from DEP, Water Resources Unit, Wetlands Management Section. - Permit for Discharge of Fill Material into U.S. Waters (pursuant to section 404 of the Clean Water Act and section 10 of the Rivers and Harbors Act) from the U.S. Army Corps of Engineers. - Water Quality Certification (pursuant to section 401 of the Clean Water Act) from the DEP, Water Resources Unit, Wetlands Management Section. in addition, because the project is within the 100-year flood zone on the community's Flood insurance Rate Map and in- volves State funding, it must comply with Executive Order 18 on floodplain management which is administered by the DEP Water Resources Unit. IRREVERSIBLE AND IRRETRIEVABLE COMMITMENTS As is the case with any construction projectr the materials utilized and the energy and capital expended to complete the project must be viewed as irreversible and irretrievable commit- ments of resources. Neither the nature nor quantity of these expenditures are considered to be sufficiently significant, when compared to benefits of the project, to warrant any reappraisal of the proposal. The principal construction materials are the concrete, timber and hardware for the culvert and vault, training walls and tide and sluice gates. The energy consumed will be the gasoline and diesel fuel powering the construction equipment. (A more energy intensive alternative involving pumping stations was rejected.) State capital for the project has already been allo- cated by the General Assembly through Special Act 83-17, Section 2(e)9. The land which the proposed diversion traverses will be *tted to this flood control use for the foreseeable future commi and can also be considered to be an irreversible commitment. The inland areas of open channel will have the natural character of a tidal creek. The open channel crossing the sandy beach will result in the loss of 300 square yards of this recreational resource. -52- TABLE 5 CHARACTERISTICS AND OCCURRENCE OF SUBMERSED AQUATICS IN THE LOWER MOBILE-TENSAW RIVER DELTA. SPECIES DESCRIPTION OCCURRENCE (common Name) Charophytes - CHR Macroscopic, sub- Bays, creeks, rivers, merged algae with bayous (Muskgrasses, stoneworts) upright green stems; main axis branched, divided into alter- nating long and short internodes from which arise whorls of branchlets. Generic distinctions may be made on the basis of the struc- ture of the branch- lets - simple (Chara), forked (Nitella) or monopodial (Tolypella). Eichhornia crassipes Ec Aquatic herb with Sluggish creeks, dead rosettes of leaves, end canals, log jams (Water-hyacinth) free-floating or and bayous. stranded in mud. Leaves ovate, petioles usually spongy-inflated. Inflorescence spicate, flowers few. Perianth blue with yellow streaks, 2-lipped, s howy. Fruit an ellipsoid capsule. Heteranthera dubia Hd Submersed aquatic Bays, creeks, rivers (Water star-grass) with sessile, linear bayous. leaves. F 1 owe rs solitary, exerted from a terminal spathe. Perianth lobes yellow, linear fruit a capsule. Hydrochole carolineinsis -Hc Submersed, weak- Slow moving streams, stemmed, freely bran- lakes and headwaters (Watergrass) ching herb; leaves of rivers. flat, up to 5 cm long and 4 mm wide. 19 TABLE 5 CHARACTERISTICS AND OCCUPPENCE OF SUBMERSED AQUATICS IN THE LOWER MOBILE-TENSAW RIVER DELTA. SPECIES DESCRIPTION OCCURENCE (common Name) Myriophyllum spicatum - Ms Rhizomatous, branching Creeks, bays, rivers perennial herb; leaves esp. Chacaloache Bay, (Eurasian Watermilfoil) whorled, pinnately Big Bateau Bay, Bay divided, 14-21 pairs Minette Basin & Bay, of leaflets; leaflets Delvan Bay, Bay Grass approximately 1.8 cm long; Flowers axillary. Najas guadalupensis - Ng Submersed aquatic herb Bays, creeks, rivers, with slender branching bayous. Appears (Common Water Nymph, stems; leaves opposite, most abundant in Bushy Pond Weed) linear, simple, up to shallow waters (.5m 2 cm long and 1.5 mm or less) esp. wide, leaf margins Chuckfee Bay, finely serrulate, Justin's Bay, Little bases sheathed; flowers Bay John axillary, sessile. Majas minor - Mi Bushy-branched, Gravine Island Bay submersed annual. was the only site (Yellow-lotus) Leaves opposite where this species stiff, with coarsely was encountered spinulose teeth, usually recurved. Flowers axillary; staminate and pistillate flowers. Fruit a greenish achene. Nelumbo lutea - Nel Rhizomatous perennial Creeks, bays, rivers. with emergent, Greatest abundance alternate leaves. along Tensaw River. Leaves orbicular, entire, peltate; some floating, some emergent; petioles to 1 meter or more long. Flowers solitary on long peduncles. Periantl parts numerous, yellow; sepals grading into petals. Fruit acorn-like; imbedded in an obconic, flat-topped receptacle. 20 TABLE 5. CHARACTERISTICS AND OCCURRENCE OF SUBMERSED AQUATICS IN THE LOWER MOBILE-TENSAW RIVER DELTA. SPECIES DESCRIPTION 0CCURENCE (common Name) Nuphar luteum - N1 Rhizomatous, aquatic Margins of fresh water perennial with sub- streams, lakes, ponds, (Spatter-Dock, mersed or emersed protected coves of Cow-Lily, Yellow leaves; leaves sub- rivers. Pond Lily) orbicular to lan- ceolate, up to 5 dm long and 3 dm wide; flowers axillary, yellow or sometimes with reddish tinge. Nymphaea mexicana - Nm Perennial aquatic Big Bay John. herb with floating (Yellow Water-Lily) leaves. Leaves ovate - oval to orbicular, entire, green above, purple below. Flowers floating, sepals 4, green; petals numerous, bright yellow. Fruit berry-like, many seeded. Nymphaea odorata - No Rhizomatous, perennial Creeks, bays, bayous aquatic with floating (White Water-Lily, leaves; leaves entire, Pond Lily) suborbicular, up to 3 dm wide, bases notched to petiole, leaf purple below; flowers floating. Nymphoids aquatica - Na Rhizomatous, aquatic Freshwater stream perennial with floating margins, ponds, leaves suborbicular with lakes. (Big Floating Heart) cordate bases, up to 20 cm long, upper leaf sur- face green, purple be- neath. 21 TABLE 5 CHARACTERISTICS AND OCCURRENCE OF SUBMERSED AQUATICS IN THE LOWER MOBILE-TENSAW RIVER DELTA. SPECIES DESCRIPTION OCCURENCE (common Name) Potamogeton crispu - Pc Rhizomatous, herbaceous Creeks, shallow bay aquatic with submersed margins, rivers (Curly Pondweed) leaves; leaves linear oblong, up to 10 cm long and 10 mm wide, undulate, sessile, with conspicuously toothed margins. Potamogeton illinoensis Pill Rhizomatous peren- Major river courses, nial with both especially Tensaw submersed and River. floating leaves. Submersed leaves thin, translucent, often arcuate, elliptic to linear. Floating leaves elliptic or ovate ending in a blunt mucro. Spike of 8-15 whorls of flowers. Fruits greenish, obovate, suborbidular or ovate. Potamogeton nodosus - Ph Perennial aquatic Rivers, creeks, bayous. herb with floating and submersed leaves. Submersed leaves linear or lan- ceolate. Floating leaves elliptic, long petioled. Spike of 10-17 whorls of flowers. Fruit brownish or reddish, obovate. TABLE 5 CHARACTERISTICS AND OCCURENCE OF SUBMERSED AQUATICS IN THE LOWER MOBILE-TENSAW RIVER DELTA. SPECIES DESCRIPTION OCCURRENCE (common Name) Potamogeton pectinatus Ppect Rhizomatous perennial Major river courses. herb. Leaves all submersed, linear - filiform, appearing to originate at the top of the sheath. Spikes conspicuously interrupted by 2-4 unequal, remote whorls of flowers. Fruits obliquely obovate. Potamogeton perfoliatus Submersed rhizomatous Major river courses. var. bupleuroides - Pperf herb. Leaves widely ovate, cordate at base and clasping, margins often undulating. Spikes short-cylindric, with 2-8 whorls of f1owers. Fruits light brown or tan; obovate. Potamogeton pusillus Pp Perennial aquatic Creeks, rivers, herb with freely bayous, bays (Slender Pondweed) branched stems; leaves submersed, linear, up to 7 cm long and 3 mm wide. Usually with two small, translucent glands at base, leaf free from stipule. Utricularia sp. - Utric. Aquatic or terres- Sluggish waters- trial herbs with heads of freshwater alternate or whorled streams protected leaves; leaves dissec- coves along rivers. ted or very fine, linear; insect trapping bladders borne on the leaves; Scapes elongate flowers; white, yellow or purple. 23 the reduction in flooding will make the Great Creek neighborhood a more desirable place to live and because of individual and col- lective property and neighborhood improvements. This will bene- fit residents selling their. homes and also benefit the City of Milford as the increased property values are reflected on the g-rand list and produce greater tax revenues. Though not as important of a consideration as flood control, a. second major benefit of this project will occur in the form of the restoration of the Great Creek marsh to an active salt marsh. The biologic gains from such 'a restoration are numerous but there are other areas which will yield bonus dividends. Such areas would include alleviation of a fire hazard, improved mosquito control, greater recreation potential and improved aesthetics. Implementation of the project described will allow enhanced tidal flushing within the marsh. With standard tide gates which permit only outflow, restoration of the marsh would not be ef- fected. However, the self-regulating tide gates incorporated into this project permit bidirectional flow. Twice each day incoming tides will have access to the marsh and can enter and cover the marsh. The amount of acreage covered each day will-, depend on the height of the high tide which varies with the lunar cycle. Nevertheless, the eventual result will be the loss of the dominant Phragmites cover and its replacement -by characteristic salt marsh species, principally Spartina alterniflora, Spartina patens and Distichlis spicata. The resultant salt marsh will offer habitat to a much wider range of avian species as well as reintroducing marine and estuarine species including mussels, clams, oysters, crabs and shrimp. Both the range of species and the absolute number of individuals will be much greater in the restored marsh system. By comparison, the Phragmites environment offers only restricted habitat opportunities and a much lower overall productivity. This has been demonstrated at Pine Creek in Fairfield, where a similar restoration effort has been suc- cessfully undertaken. Another value attached to the restoration of the Great Creek marsh to its original salt marsh state is the reduced danger of both nuisance and catastrophic fires. Again it is difficult to determine an average damage figure attributable to marsh fires. The costs attached to the small nuisance fires, either accidental or intentional, stem from the expenses of the Milford Fire Department in dousing these blazes. While there are no records kept by the Fire Department, DTC has estimated a cost of $6,000 per event. This figure is based on a U.S. Army Corps of Engineers standard of $3,000 to $5,000 per marsh fire. However, as this standard is based on an area having roughly half As many homes as the Great Creek neighborhood, DTC considered a figure of .$6,000 per event to be reasonable in this instance. They have also estimated a marsh fire frequency of 87 events in a 100 year period which equates to an annual cost figure of $5,220 in cur- rent dollars to combat such fires. This number is inclusive only -58- of the municipal expenses to mobilize fire fighting men and equipment., It does not include damage to the structures. Of greater consequence than the smaller more frequent fires is the ever present possibility of a catastrophic blaze which could cause the loss of many marshside homes. Phragmites is excellent fuel for a fire. In dry weather, especially with the current minimal inflow of tidal waters, the marsh can become a literal tinderbox capable of spreading a blaze with alarming speed. Even under less than ideal conditions, the dried canes of the previous year's growth represent a potent fuel supply for any flame which can take hold. Fires in this and other similar Phragmites beds are frequent enough that the possibility of a fire getting out of control is a very real threat. Given the extreme proximity of the homes at Great Creek to the marsh, it is a very fortunate thing that a seriously destructive fire has not yet had the chance to do its damage. After a successful conversion of the Great Creek marsh to salt marsh species, the fire danger will be greatly reduced. First of all, Spartina species do not constitute a fire hazard because they do not offer the same fuel value. Neither Spartina alterniflora nor Spartina patens develop any persistent woody cane structure. Both decompose much more quickly than Phragmites. Secondly,, the increased tidal inflow will saturate the marsh twice daily thus insuring perpetually moist conditions, even during periods of prolonged dry weather. This will make it much more difficult for a fire to start and for any fire, once started, to propagate itself. Thus, with a greatly reduced fuel supply and less favorable conditions for combustion, the existing threat of fires is defused. Similarly reduced will be the mosquito breeding potential of the-marsh. Fresh and/or brackish water mosquitos currently breed in the marsh at sufficient levels that they pose an annoyance to local residents. This is made possible by the numerous stagnant pools which form and eventually dissipate yielding ideal condi- tions for mosquito production. The lack of flushing -and the temporary nature of the stagnant pools have made past mosquito control efforts less than successful. Mosquito control efforts will be benefitted by the diurnal rinsing of the marsh by the incoming tidal flows. This flushing will operate to eliminate stagnant water conditions critical to egg laying and to avoid the later drying period so necessary for larvae development. The salinity increase will also work to the detriment of the existing freshwater or brackish water mosquitos in the marsh. Additionally, the reduction of the Phragmites cover will facilitate mosquito control efforts by providing easier access into the marsh for control operations and by expos- ing breeding pools,to aerial spraying. It is probable that salt marsh mosquitos will move into the created niche, probably occupying areas of high salt marsh around _59- the periphery of the system. Areas of likely concentration would be those-inundated only by the spring high tides. If, and to the extent that this problem may develop, control of salt marsh mosquitos is a much easier problem to deal with. 'Open marsh water management techniques have been highly successful at sig- nificantly reducing salt marsh mosquito population levels in other areas. Therefore, at best we can expect to substantially solve the existing mosquito problem while at worst, we will swap the current difficult mosquito management problem for a battle we are much more likely to win. One final benefit arising form the marsh restoration will be the aesthetic improvement. Fields of waving marshgrass represent a major visual improvement as compared to acres of dead, continu- ous, impenetrable Phragmites stalks. The additional bird life which will inhabit the salt marsh will also provide eye- and ear- appealing amenities which will afford birders and casual ob- servers extra viewing or recreational opportunities. Elimination of the existing clog-prone outlet works of the creek will result in a savings to the City of Milford as public works crews need not be regularly dispatched to clean out the pipe and channel. The Public Works Department estimates the annual expense for channel maintenance at $10,000. Of course, the new outlet works will require some reduced level of mainte- nance periodically. Therefore, the net savings realized will be somewhat less than $10,000. -60- APPENDIX A THE DEVELOPMENT AND FUNCTION OF THE SELF- REGULATING TIDE GATE The self-regulating tide gate is a structure, generally used in con3unction with a drainage structure such as a metal or concrete pipe, to manage the flow of tidal water into a small cove or tidal marsh system. Unlike conventional tide or flapper gates, which when functioning, only permit unidirectional flow through a culvert or other. drainage structure, the self- regulating tide gate permits bidirectional flow. That means that during an ebbing tide, water can flow from the marsh seaward into the Sound or adjacent tidal water body and during a flood tide, the water can move unimpeded back into the marsh. It therefore allows the marsh to be subject to a more or less natural regime of tidal flooding. Conventional gates on the other hand, usually permit drainage of excess waters from the marsh into the Sound during an ebbing tide but, on a rising or flood tide., will not permit tidal salt water to enter into the marsh. Conventional tide gates as noted above only permit unidirec- tional flow when properly functional. Along the Connecticut coast, most of these gates were installed during the 1920's to the 1940's for the purposes of controlling mosquitoes. In gen- eral, the environmental changes that occur to a salt marsh lo- cated landward of one of these structures is as follows: 1. There is a partial or complete elimination of all tidal inflows to the marsh. 2. Concurrently, the water table in the marsh can drop usually on the order of 2' to 31 and the salt water content of soil and creek water will diminish and at times become entirely fresh in nature. In some areas, the potential lowest elevation of the water table corresponds to the lowest elevation of the culvert to which the tide gate is attached. 3. The marsh peat often 'subsides' to a level which can be lower than neighboring healthy marsh systems by one to two feet. This phenomenon may simply be a function of greater aeration in the surface soil resultant to the lowering of the water table. This in turn accelerates the decomposition rates of the organic material in the soil. 4. These environmental conditions represent optimum habitat for an aggressive albeit indigenous grass called reed (Phragmites australis). This grass will displace native salt marsh grasses and ulti- mately form a monoculture that stands 51 to 81 tall. Reed also transpires large volumes of water and may be a contributing factor to the lowering of the water table. These changes also culminate in a number of social problems. First, wherever reed becomes established and abundant, it poses a potential and serious fire hazard. Since reed does not decompose readily, any marsh can quickly accumulate large volumes of com- bustible materials that can burn quickly and produce a very hot fire. In the town of Fairfield, the reed marshes, formerly healthy salt marshes, became a recurrent fire hazard that not only resulted in annual damage losses to homes, appurtenant structures and automobiles# to name but a few, but the town also incurred an annual cost of approximately $30,,000 to fight and contain these fires. Secondly, drainage creeks, ditches and structures accumulated sediment due to poor flushing rates, thereby necessitating periodic maintenance and cleaning. Inci- dental to this,, during inland storms, the presence of clogged structures would cause stormwater to back up and flood streets and property. Last, but not least, the capacity to harvest some of the natural resources such as fish and crabs was eliminated as the area degraded. The sea of reed also results in the loss of once majestic vistas and probably contributes to lower property values. In the town of Fairfield, structures in certain flood prone coastal areas were floodproofed by the construction of earthen dikes. Into the dikes were installed conventional tide gates which would allow stormwater to drain into the Sound, at'least when the tide gates were operative. In certain areas,, this protection against coastal flooding increaseed the level. of inland flooding. All of the degraded marshes became fire haz- ards. In an effort to resolve these problems and to restore the social and biological values of these marsh areas, the Conserva- tion Director,, Mr. Thomas Steinke, devised the self-regulating tide gate. The concept of the self-regulating tide gate is a fairly simple one. Installation of a self-regulating tide gate permits the reintroduction of tidal flows and' salt water. The elevation of the water table increases as does the salt content. These two factors alone contribute to arresting the spread of reed and actually inducing the re-establishment of salt marsh vegetation. This is a gradual process since reed is so tenacious in certain areas that restoration of tidal flows sometimes needs to be augmented by physical control of reed. Usually, the re-establishment of normal tidal flows does not threaten property or structures with tidal flooding. However, where elevated storm tides are a.major concern and problemy self- regulating tide gates can incorporate a feature which allows for control during storm events.. Attached to the gates are a set of floats that can be adjusted to a specified level to prohibit the introduction of flood waters. When the incoming tide reaches this elevation, the gate closes. In this manner, restoration of salt marsh can occur and flood protection can be provided to land surrounding the marsh. Through the yearsf the self-regulating tide gate has under- gone numerous modifications and improvements. The present de- sign, which has been functioning for 3 years, appears to be very reliable. Tidal flooding has been controlled and the marshes receive adequate volumes of tidal water to facilitate restoration of salt marsh. Where conventional gates can fail due to flotsam, boats or mattresses, to name a few, preventing the gate from closing, the self-regulating tide gate never becomes locked open with debris. Also, in the event of the coincidence of a major coastal storm and inland storm, the self-regulating tide gate can be manually locked closed at low tide to increase the flood storage area in the marsh. The marsh can accommodate more storm water without causing flooding due to the combination of these two storm events. .APPENDIX B MARSH RESTORATION AT GREAT CREEK Historical Persective Figure 2 depicts the nature and extent of the marshes in the vicinity of Myrtle and Silver Sands beaches in the 1800's. At that time, the system was complex and was comprised of approxi- mately 300 acres. There were two primary inlets located at either end of a barrier beach. The eastern one was Great Creek located between Fort Trumbull and Silver Beaches. The second was Fletchers Creek located at the southeastern end of Silver Beach. Both of these discharged across a wide sand flat located south- east of the beaches. At the eastern end of Myrtle Beach was a third small tidal creek which supplied tidal water to the west- ernmost area of this complex. The Great Creek system was separated from Long Island Sound by three barrier beaches, namely Fort Trumbull Beach, Silver Beach and Myrtle Beach. Between Myrtle Beach and Silver Beach, there was no barrier beach but simply a seri.es of discontinuous sandy ridges. This may have been a function of 1) the absence of an adequate sand supply at this location historically 2) the protection afforded to this area by Charles Island and the bar preventing the formation of a large barrier or 3) the wave re- fraction induced by the location of Charles Island concentrating wave action at this site and inducing erosion. Even today, this area supports little if any barrier and is prone to erosion. The width of Great Creek at the juncture of the two barrier beaches only measured approximately 201. Despite this small width and the even smaller widths of the other two creeks, ade- quate tidal flows were provided to the marsh for it to remain mostly salt marsh. Although the creeks crossed an expanse of active sandflat, the creeks were self-maintaining. Degradation of the Great Creek System Since the turn of the century, a number of activities have contributed to the degradation of the Great Creek system. These include filling to accommodate roads such as East Broadway and structures such as residential cottages and the use of the area for landfill operations. The latter evidently was the largest single filling operation with the greatest effect on the salt marsh. The culvert that presently provides the connection between the marsh and Long Island Sound reduced the original creek width by 80%. Further., the tide gate that is located in the manhole in this line along with sediment that has accumulated in the pipe has significantly reduced tidal flows to the Great Creek marsh. TABLE 8. RELATIVE ABUNDANCE OF DELTA SUBMERGED AQUATICS IN DESCENDING ORDER OF ABUNDANCE, 1956. (After Baldwin, 1957). COMMON NAME SCIENTIFIC NAME SYNONOMY LUETH Bushy Pondweed *Naias uadalupensis Southern Naiad Wild Celery *Vallisneria spiralis Narrow-leaved Pondweed *Potamogeton pusillus type P. foliosus *Water Stargrass Heteranthera dubia Muskgrasses *Nitella spp. Characeae Horned Pondweed *Zannichellia palustris *Ribbon-leaf pondweed Potamogeton robbinsii P. epihydrus Longleaf Pondweed Potamogeton nodosus (P. fluitans, Small?) Coontail Ceratophyllum demersum Watermilfoil Myriophyllum sp. Marestail *Fanwort Cabomba caroliniana *Desireable waterfowl food. jurisdiction. The structure of the State's mosquito control effort was to accept the responsibility for maintaining mosquito ditches and structures only after a town had secured its own funding to have mosquito control activities conducted in that town. If the marsh was in good condition following the mosquito control practices, usually ditching, then the State's mosquito control program accepted jurisdiction over the long term mainte- nance of those marshes. However, the State's mosquito control program never accepted maintenance of those areas where the mosquito control actions were initiated under the WPA program (almost all of these were conducted in' towns which had not by that date ditched their marshes). Today therefore, Milford is a town in which the Mosquito Control Division of the Connecticut Department of Health Services does not accept jurisdiction or responsibility for any mosquito control actions or related structures. I In the report referenced above, there is documentation of the replacement of existing tide gates, building of two tide gate manholes, installation of three culverts and replacement of one culvert. This report not only indicates that tide gates were present' prior to 1935, but also that the replacement was con- ducted under the WPA program. Subsequent to WPA projects like this one, the Mosquito Control Division applied multiple times to the Connecticut Legislature to manage and maintain these addi- tional areas. Funding was never appropriated and responsibility to maintain the ditches in this marsh and any associated struc- tures was never accepted by the Mosquito Control Division. Restoration of the Marsh Degraded wetlands such as this can be restored through the re-establishment of tidal flushing. Such restoration projects have been successfully undertaken at Pine Creek in Fairfield and Barn Island in Stonington. Another is being planned at Ash Creek in Fairfield. The elevated tidal levels and salt content of the soil reduce the vigor of reed and ultimately induce the replace- ment of reed by salt marsh vegetation. In this system, to re- store salt marsh will require the reintroduction of sufficient quantities of salt water which will periodically inundate most of the marsh surface at least twice a month. This will require a drainage structure such as a culvert or a series of culverts which provide a significantly greater cross-sectional area than the present culvert does. Also a larger cross sectional area will facilitate faster dewatering of the marsh during inland storms. Coastal flood control can be achieved through various means but perhaps the best in this case would be a series of self-regulating tidal gates. In this manner, the salt marsh can be restored, backflooding can be reduced or entirely eliminated and tidal flooding during extreme storm tides can be controlled. APPENDIX C RESULTS OF FLORA AND FAUNA SURVEY The following tables,, maps and text are excerpted from a report entitled Final Environmental Re2ort, Great Creek Flood Control Project, Silver Sands State Park, Milford, Connecticut (June 1983) prepared by Dr. Karl Eric Tolonen as a part of the research for Diversified Technologies Corporation's Pre-design Report. The species tables are reproduced in their entirety. Maps and text are included sufficient to locate the sampling sites and explain the rationale for their selection. FINAL REPORT SILVER SANDS STATE PARK INTRODUCTION The Great Crook area of Silver Sands State Park, Milford, Connecticut, has been subject to flooding problems for acme time* The author of this report has visited the site twelve times to gather various.environmental data, which are to be used in assistance of the engineering design of flood-alleviation measures. This is the final report of findings, all laboratory analyses having been completed. It should be noted that the project timetable required field work during the winter. The potential impact of this is discussed within each section dealing with the'findings of the field investigations below. This final report incorporates responses to all questions and comments received relating to the Revised Preliminary Report (ref. 1). In this report, "northern" refers to the area along Mayflower Place, wwasternw'refors to the area along NettletonAvenue, *southern* refers to the East Broadway area, and *eastern" refers to areas along Surf Avenue. ZY9 DR* KARL ZXXC TOLOUXU ENVIRONMENTAL ANALYSIS FINAL REPORT SILVER SANDS STATE PARK INVESTIGATIONS VASCULAR VEGETATION I h.eve taken six collections of vascular vegetation and havi made additional observations of vegetation at other sites representing primarily the wetland areas of the Park (Figure 1. Tables I - T). The scope of this study was limited to understanding potential impact of drainage alterations on the Park's watland habitats. Tables I through 6 contain lists of plants collected and identi- find at the sampling points marked'on Figure 1. Because of the condition of the vegetation at.@this time of year (January - March), most collections contained some unidentifiable specimens. Also, most herbaceous species had not yet appeared, so the plant list in much shorter that 'would be axpected were the work done during the summer. It should be noted that Phgagmitn AUltralip is present throughout the Park; I collected only one specimen for verification (Table 1). Although a variety of sources were used for identifying specimens, all terminology in Tables I - 6 follows Dowhan (ref. 2). The major wetland units identified are an extensive Pbracmites marsh occupying much of the Great Crook area, and a series of fresh- water wetlands (marsh, swamp, pond, and stream types) along the northern and western boundaries of the Park. Collection Ml-V (Table is typical of ths upland fringe of the marsh, with soms watland species and some drier habitat once M2-V (Table 2) was selected to represent maximal saltwater influence. Even at this station, true saltmersh species are overshadowed by Phracmitea, with Spgrtina limited to a narrow fringe along the Creek. The remaining 4 stations represent the freshwater watlands.along the northern and western boundaries. Stations M3-V, MS-V and M6-V support a high diversity of Bys 02. XAXL 2XIC TOLONZA -2- ENVIRONMENTAL ANALYSIS. FINAL REPORT SILVER SANDS STATE PARK INVESTIGATIONS .of watland plants, many of them of considerable value to wildlife (examples: Mer, Alnus, Cornust Elas�sin!g, Lindera, *Qu6:equs, Rhus, Sambucus, Toxicodendron, Viburnum) Songbirds were notably a6undant at these a5tes. Collection M4-V comes from the drainage channel along Nettleton Avenue. This channel is now dominated by PhragMij_e_9@ but was mapped-as Typha (cat-tail) by Geraghty L Miller, Inc. (ref. 31 Other than this change, the vegetation of the Park is essentially as shown an their map. No plant collactions were made at the following stations, but all were dominated by Phragmites: M12-A and M13-A an Surf Avenue; M22-C; M15-A, M20-C and M21-C near James Street; the large depression west of Cooper Avenue; and the a-ran of Fletcher's Creek. Plant species are used in Section 22a-29 an part of the legal definition of "Tidal Wetlands*, and several of these species occur within the Park (Table T). I would expect a more detailed vegetation study, during the summer, to find more than 20 of these species (from Section 22a-29) within the Park. Most of them are herbaceous, so would be unlikely to be found in March when most plant collecting was done. SUMMARY-VASCULAR-VEGETATIONs 1).Most of the site is dominated by Phragmijes. See following section "PRESENT CONDITION* for a detailed discussion of this plant. 2) Th a freshwater wetlands along the northern and western Park boundaries have considerable diversity and value for wildlife. 3) Although presently regulated as an Inland We'tland, the sit@ could @ t 4S fa be classified me, a Tidal Watlandg.based on the vegetation. Byt OR MAIL ZRIC TOLOURN -3- ENVIRONMENTAL ANALYSIS Figure 1. Sampling points for vegetation. IIA) Ow 000 M6-- 0 low 4- M2-V MI-V Mstv,r VIP % .03 a 4 % 41. 000 4 40@ 4b *% 0 i to Nei - '6h IIN 4f 4 or 10 5 M4-y ch *44;k i,06 Beach Figure 2. Sampling points for aquatic organisms. IIB) OW Al 2 0 -1411 -3 0 M 1..3mA 746 0 4b- -*law MIO-A 441 B@A d1b ;WI 4-A laze A' 0141 9-,A 64 A AP JO A AS Ak_ 'k Ok -6h JO(dr 4 49 101b Ali4 43 0.: 0. 6-bA -0 46 v J,1*MbO (a's 00 So r 'go A. 00. 0 ea ch 000... o 00', 0... 0*0 :0 O.:.@ &aCh F FINAL REPORT SILVER SANDS STATE PARK. TABLE I Collection MI-V VASCULAR VEGETATION 3 January 1983 FAMUX3 "gon ggllecte@ Anacardiacess JLbMj clobra Bigmoniaceas Catalpa op. Composites probably Contaurell Composite@ Genus ? Cucurbitaceas Echinggigtil lobato Fogaceas gungwo op. Gramineas j!Mnicum op. Gromineas *Ehracmites aus1rallp. Phytolaccaceas Ehytolacca americame Polygonaceas probably Raynoutr" sp. Scrophulariaceas probably Linaria op. *This species present throughout the Park; collected only at this station. Note: on Tables 1-17, a indicates uncertainty of idefitification. F I 7NAOLc i' Call SYs DR. KARL XRZC TOLONZ9 @27- ENVIRONMENrAL ANALYSIS Type III A. Low Marsh Trees and Shrubs (occasional) Cephalanthus occidentalis (Buttonbush) Cornus stricta (Swamp Dog-wood) Fraxinus caroliniana (Water Ash) Nyssa sylvatica, var. biflora (Swamp tupelo) Taxodium distichum (Bald Cypress) Herbs Acnida cuspidata (Water Hemp) (Alligator Weed) Alternanthera, philoxeroides Asclepias lanceolata (Milkweed) Aster tenuifolius Bacopa, monnieri Bidens laevis; B. mitis (Beggars tick) Boltonia asteroides Cicuta maculata (Water Hemlock) Crinum americanum (Swamp Lily) Galium tinctorium (Bedstraw) Hydrocotyle bonariensis; H. umbellata (Pennywort) Hymenocallis occidentalis (Spider Lily) Iris virginica Justicia americana (Water Willow) Lilaeopsis chinensis Ludwigia glandulosa; L. leptocarpa ... Lythrum lineare (Loose Strife Orontium aquaticum (Golden Club) Peltandra virginica (Arrow Arum) Pluchea odorata (Marsh Fleabane) Polygonum hydropiperoides; P. punctatum (Smartweed) Pontederia cordata (Pickerel Weed) Ptilimnium capillaceum (Bishop Weed) Sagittaria falcata Sagittaria latifolia (Arrowhead) Saururus cernuus (Lizard's Tail) Sium suave (Water Parsnip) Sphenoclea zeylanica (Chicken Spike) Typha domingensis; T. latifolia (Cat Tail) 41 Grasses and Sedges Carex alata, C. glaucescens Carex hyalinolepis Cladium jamaicense (Saw Grass) Cyperus filicinus; C. haspan (Umbrella Sedge) Cyperus odoratus; C. virens Distichlis spicata Echinochloa crus-galli, E. walteri (Water Grass) Eleocharis elongata; E. equisetoides (Spikerush) Eleocharis quadrangulata; E. obtusa Juncus effusus (Soft Rush) Juncus roemerianus (Needle Rush) Leesia hexandra; L. oryzoides (Cut Grass) Panicum dichotomif1orum (Fall Panic Grass) Panicum hemitomon (Maidencane) Rhynchospora corniculata (Beak Rush) Sacciolepis striata Scirpus americanus (Three- square-Bul rush) Scirpus californicus (Giant Bulrush) Scirpus robustus (Salt Marsh Bulrush) Scirpus validus (Soft-stem Bulrush) Zizania aquatica (Wild Rice) Zizaniopsis miliacea (Southern Wild Rice) 42 Type III B. High Marsh Trees, Shrubs and Woody Vines (scattered) Amorpha fruticosa (Bastard Indigo) Baccharis halimifolia (Sea Myrtle) Hibiscus militaris (Marsh Mallow) Hibiscus moscheutos Ilex vomitoria (Yaupon) Kosteletzkya virginica (Seashore Marsh Mallow) Myric cerifera (Wax Myrtle) Salix nigra (Black willow) Sambucus canadensis (Elderberry) Sesbania macrocarpa Sesbania vesicaria (Bladder Pod) Wisteria frutescens Herbs (Including Grasses and Sedges) Andropogon virginicus (Broomsedge) Bidens mitis; B. frondosa (Beggars Tick) Calystegia sepium (Hedge Bindweed) Carex hyalinolepis Eupatorium serotinum (Fall Boneset) Euthamia minor (Flat Top Goldenrod) Helenium autumnale (Sneeze Weed) Ipomoea sagittata (Morning Glory) Mikania scandens (Climbing Hempweed) Osmunda regalis (Royal Fern) Panicum repens (Torpedo Grass) Panicum virgatum (Switch Grass) Phragmites australis (Common Reed) Pluchea camphorata; P. odorata (Marsh Fleabane) Solidago sempervirens (Seaside Goldenrod) Spartina cynosuroides (Big Cordgrass) Spartina patens (Saltmeadow Cordgrass Teucrium canadense (Germander) Thelyptersis palustris (Marsh Fern) Vigna luteola 43 Type VI. Bay Forest Trees Acer rubrum (Red maple) Chamaecyparis thyoides (White Cedar) Gordonia lasianthus (Loblolly Bay) Liriodendron tulipifera (Tulip Tree) Maqnolia grandiflora (Southern Magnolia) Magnolia virginiana (Sweet Bay Magnolia) Nyssa sylvatica var. biflora (Swamp Tupelo) Osmanthus americana Persea palustris (Swamp Bay) Pinus elliottii (Slash Pine) Quercus laurifolia (Laurel Oak) Q. nigra (Water Oak) Salix nigra (Black Willow) Taxodium distichum var. nutans (Pond Cypress) Shrubs and Vines Alnus serrulata (Hazel Alder) Arundinaria gigantea (Cane) Clethra alnifolia(Peper Bush) Cliftonia monophylla (Black Titi) Cyrilla racemiflora (Titi) Decumaria barbara (Climbing Hydrangea) Ilex coriacea Large Gallberry) Ilex vomitoria (Yaupon) Illicium Floridanum (Star Anise) Itea virginica (Virginia Willow) Leucothoe axillaris (Fetterbush) Lyonia lucida (Fetterbush) Myrica cerifera (Wax Myrtle) Smilax glauca (Green Briar) S. Laurifolia (Green Briar) Viburnum nudum (Possum-Haw Viburnum) Vitis rotundifolia (Muscadine) Herbaceous Plants Carex glaucescens (Sedge) Eleocharis flavescens...(Spike Rush) Gratiola virginiana (Hedge Hyssop) Hypericum mutilum (St. John's Wort) H. virginicum Juncus debilis; J. diffusissimus...(Rush) Leersia virginica (Rice cutgrass) Lindernia dubia (False pimpernel) Lycopus rubellus (Water Horehound) Orentium aquaticum (Golden Club) Osmunda cinnamomea (Cinnamon Fern) O. regalis (Royal Fern) 44 Bay Forest (Continued) Peltandra virginica (Arrow-Arum) Polygonum punctatum (Smartweed) Rhynchospora millacea (Beak Rush) Thelypteris normalis (Widespread Maiden Fern) Woodwardia areolata (Net Vein Chain Fern) Xyris iridifolia (Yellow- Eyed Grass) 45 Type X. Alluvial Swamp Trees Acer rubrum var. drummondii - (Red Maple) Carya aquatica (Water Hickory) Diospyros virginiana (Persimmon) Fraxinus caroliniana (Water Ash) Fraxinus pennsylvanica (Green Ash) Fraxinus profunda (Pumpkin Ash) Ilex opaca (American Holly) Liquidambar styraciflua (Sweetgum) Magnolia virginiana (Sweet Bay) Nyssa aquatica (Water Tupelo) Nyssa sylvatica var. biflora (Swamp Tupelo) Persea palustris (Swamp Bay) Platanus occidentalis (Sycamore) Populus deltoides (Cottonwood) Populus heterophylla ( Swamp Cottonwood) Quercus laurifolia (Laurel Oak) Q. nigra (WaterOak) Salix nigra (Black Willow) Taxodium distichum (Bald Cypress) Ulmus americana (American elm) Shrubs Cephalanthus occidentalis (Buttonbush) Cornus stricta (Swamp Dogwood) Ilex verticillata (Winterberry) Ilex vomitoria (Yaupon) Itea virginica (Virginia willow) Myrica cerifera (Wax myrtle) Sabal minor (Dwarf Palmetto) Styrax americana (Snow Bell) Woody Vines Ampelopsis arborea (Pepervine) Anisostichus capreolata (Cross Vine) Berchemia scandens (Rattan Vine) Brunnichia cirrhosa (Ladies' eardrops) Campsis radicans (Trumpet creeper) Smilax laurifolia (Greenbriar) Toxicodendron radicans (Posion Ivy) Vitis cinerea; V. vulpina (Grape) V. rotundifolia (Muscadine) Wisteria frutescens (Wisteria) 46 Herbs Asclepias perennis (Swamp Milkweed) Boehmeria cylindrica (False nettle) Cicuta maculata Commelina virginica (Dayflower) Cynoctonum mitreola (Miterwort) Dracocephalum virginianum (Dragonhead) Eupatorium coelestinum (Mist Flower) Gratiola virginiana Hibiscus militaris Hypericum walteri (St. John's Wort) Justicia ovata Lobelia cardinalis (Cardinal Flower) Ludwigia alternifolia, L. glandulosa Lycopus rubellus Mikania scandens (Climbing Hempweed) Onoclea sensibilis (Sensitive Fern) Osmunda regalis (Royal Fern) Polygonum hydropiperoides; P. punctatum (Smartweed) Sabatia calycina Samolus parviflorus Saururus cernuus (Lizard's Tail) Senecio glabellus (Butterweed) Spilanthes americana var. repens Spiranthes cernua var. odorata (Fragrant Ladies' Tresses) Vernonia altissima (Giant ironweed) Grasses and Sedges Arundinaria gigantea (Cane) Carex alata; C. gigantea Carex intumescens; C. louisianica .... Chasmanthium latifolium Leersia lenticularis, L. virginica (Cut Grass) Leersia oryzoides (Rice Cut Grass) Panicum gymnocarpon (Panic Grass) P. rigidulum Rhynchospora corniculata, R. miliacea ...(Beak Rush) 47 Types IV & V. Pine Savannah (Pocosin, Low Pineland, Bog) Woody Plants (Trees, Shrubs and Vines) Aronia arbutifolia (Red Chokeberry) Arundinaria gigantea (Cane) Clethra alnifolia (Pepperbush) Cliftonia monophylla (Black Titi) Cyrilla racemiflora (Swamp Cyrilla) Hypericum cistifolium; H. brachyphyllum (St. John's Wort) H. fasciculatum; H. myrtifolia Ilex coriacea (Large Gallberry) Ilex glaabra (Gallberry) Ilex cassine (Dahoon) Lyonia lucida (Fetterbush) Magnolia vlrqiniana (Sweet Bay) Myrica cerifera (Wax myrtle) Nyssa sylvatica var. Biflora (Swamp Tupelo) Persea palustris (Swamp Bay) Pinus elliottii (Slash Pine) Pinus palustris (Longleaf Pine) Rhododendron viscosum var. Serrulatum (Swamp Azalea) Rhus vernix (Poison Sumac) Smilax laurifolia (Greenbriar) Serenoa repen (Saw Palmetto) Taxodium distichum var. Nutans (Pond Cypress) Vaccinium elliottii; V. fuscatum (Blueberry) Herbaceous Plants (Except Grasses and Grass-Like Plants) Aletris aurea; A. farinosa (Colic Roof) Asclepias lanceola , A. longifolia (Milkweed) Balduina uniflora Calopogon pulchellus (Grass Pink Orchid) Chondrophora nudata (Rayless Goldenrod) Cleistes divaricata (Rosebud Orchid) Drosera brevifolia; D. filiformis (Sundew) Eriocaulon decangulare (Pipewort) Habenaria blephariglottis (White Fringe Orchid) Lachnanthes caroliniana (Red-Root) Lobelia glandulosa; L. puberula (Lobelia) Lophiola americana (Golden Crest) Pinguicula lutea; P. planifolia (Butterwort) Pogonia ophioglossoides (Rose-Crested Orchid) Polygala brevifolia; P. cruciata ( Milkwort) Polygala cymosa; P. ramosa (Yellow Milkwort) Phexia alifans; R. lutea (Meadow Beauty) Sabatia brevifolia; S. macrophylla (Rose Gentian) Sarracenia alata; S. flava (Yellow Pitcher Plant) S. leucophylla (Purple Pitcher Plant) S. psittacina (Parrot Pitcher Plant) S. purpurea; S. rubra (Red Pitcher Plant) Scutellaria integrifolia (Rough Skullcap) 48 Spiranthes praecox; S. vernalis (Ladies Tresses Orchid) Tofieldia, racemosa (False Asphodel) Utricularia cornuta; U. juncea (Bladder-wort) Xyris caroliniana; X. difformis (Yellow Eyed Grass) Grasses and Grass-Like Plants Andropogon virginicus (Broom Sedge) Anthaenantia rufa Aristida affinis; A. virgata (Three-Awn Grass) Ctenium aromaticum (Toothache Grass) Dichromena. latifolia (White-Top Sedge) Eleocharis microcarpa; E. tuberculosa. (Spike Rush) Erianthus giganteus (Plume Grass) Fuirena squarrosa; F. scirpoidea (Umbrella Grass) Muhlenbergia, expansa. (Muhly Grass) Panicum consanguineum; P. ensifolium (Panic Grass) P. spretum; P. scabriusculum Rhynchospora chapmanii; R. ciliaris (Beak Rush) R. glomerata; R. plumosa; R. pusilla Scleria ciliata; S. reticularis (Nut Rush) 49 Type VII. Upland Pine-Oak Forest Woody Plants (Trees, Shrubs and Vines) Carya tomentosa (Mockernut Hickory) Castanea pumila (Chinkapin) Ceratiola ericoides (Rosemary) Conradina canescens (Searide Balm) Cornus florida (Flowering Dogwood) Diospyros virginiana (Persimmon) Gaylussacia dumosa (Dwarf Huckleberry) Gelsemium sempervirens (Yellow Jessamine) Ilex vomitoria (Yaupon) Magnolia grandiflora (Southern Magnolia) Pinus clausa (Sand Pine) Pinus palustris (Longleaf Pine) P. elliottii (Slash Pine) Quercus falcata (SouthernRed Oak). Q. hemisphaerica (Laurel Oak) Q. incana (Blue-Jack Oak) Q. laevis (Turkey Oak) Q. margaretta (Sand Post Oak) Q. myrtifolia (Myrtle Oak) Q. virginiana (Live Oak) Q. virginiana var. maritima (Dwarf Live Oak) Rhus copallina (Winged Sumac) Sassafras albidum (Sassafras) Sereno repens (Saw Palmetto) Smilax auriculata (Greenbriar) Vaccinium arboreum (Sparkleberry) V. elliottii, V. myrsinites (Blueberry) Herbaceous Plants (Except Grasses and Grass-Like Plants) Agalinis purpurea; A. setacea (Purple foxglove) Asclepias humistrata (Sand Milkweed) A. tuberosa (Butterfly Weed) Aster adnatus; A. linariifolius (Aster) Calamintha coccinea (Red Basil) Centrosema virginianum (Butterfly Pea) Clitoria mariana (Butterfly Pea) Cnidoscqolus stimulosus (Spurge Nettle) Coreopsis major Crotalaria angulata; C. purshii (Rattlebox) Desmodium laevigtum; D. viridiflorum (Beggar's Ticks) Euphorbia corollata (Flowering spurge) Gaillardia aestivalis (Gaillardia) Galactia erecta; G. yolubilis (Milk Pea) Lespedeza stuevei; L. virginica (Lespedeza) Liatris elegans; L. graminifolia (Blazing Star) Lucinus diffusus (Sandhill Lupine) Pepsteron austrlis (Beard tongue) Phlox pilosa (Phlox) 50 Pycnanthemum incanum (Whitish Basil) Salvia azurea (Blue Sage) Schrankia microphylla (Sensitive Brier) Solidaqo odora (Goldenrod) Stillingia sylvatica (Queen's Delight) Tephrosia florida; T. chrysophylla (Hoary Pea) Tetragonotheca helianthoides (False Sunflower) Trilissa odoratissima (Deer Tongue) Vernonia angustifolia (Narrow-Leaf Ironweed) Grass and Grass-Like Plants Andropogon tener Aristida lanosa; A. purpurascens (Three-Awn Grass) Cyperus globulosus; C. retrorsus (Umbrella Sedge) Danthonia sericea (Oat Grass) Eragrostis refracta; E. spectabilis (Love Grass) Gymnopogon ambiguus (Windmill Grass) Panicum aciculare; P an ustifolium (Panic Grass) Rhynchospora megalocarpa ( Beak Rush) Scleria triglomerata (Nut Rush) Sorghastrum elliottii (Indian Grass) Sporobolus junceus (Dropseed Grass) 51 FINAL REPORT SILVER SANDS STATE PARK TABLE 13 Collection M15-A AQUATIC ORGANISMS 13 March 1983 Count: Tpxon collected: I Polychaetas Capitellidae? 1 Polychaeta: Nereidae: Nergis7 6 Crustacea: Amphipoda: Colophium? 9 Crustacea: Amphipoda: Gammaridee 28 Crustacea: Palaemonidae: Palsemonetes Puga.0 2 Osteichthyes: Anguillidaet Anguilla rostrate 2 Ostaichthyes: Cyprinodontidae: fundulus sp. 49 TOTAL NUMBER OF SPECIMENS ,Y: DR. XARL ZRIC TOLOWZH -39- ENVIRONMENTAL ANALYSIS T FINAL REPORT SILVER SANDS STATE PARK TABLE 14 Collection M16-A AQUATIC ORGANISMS 13 March 1983 Count-. Tgxon collectedi 20 Annelida: Oligochaeta I Insecta: Odonate: Coenagrionidae 1 Insecta: Odonata: Libellulidee I Insecta: Hafniptera: Corixidae 4 Insecta: Coleopters: Dytiscidae (larvae) 7 Insectai Coleoptera: Dytiscidae (adults) 2 Insecta: Coleoptera: Haliplidae (adults) I Insecta: Trichoptera I Insecta: Diptera: Ceratopogonidae 25 Mollusca: Gastropoda: Physidae? 63 TOTAL.NUMBER OF SPECIMENS ;FINAL r 11, BY: DR. XARL ERIC TOLOVEN -40- - ENVIRONMENTAL ANALYSIS FINAL REPORT SILVER SANDS STATE PARK TABLE 15 Collection M17-A AQUATIC ORGANISMS 13 March 1983 Count: Taxon collected.: 11 Insecta: Hemiptera: Corixidae 133 Insecta: Diptera: Chironomidee 144 = TOTAL NUMBER OF SPECIMENS* *NOTE: Picked through several subsamples of a large collection and counted. Remaining specimens were discarded. The entire collection was scanned and only these two taxa were seen. DR. KARL ZRIC TOLOVEN -41- WNEWNEW ENVIRONMENTAL ANALYSIS INVESTIGATION OF A WEIR DESIGN ALTERNATIVE FOR COASTAL FISHERIES BENEFITS BARTON D. ROGERS, M.S. WILLIAM H. HERKE, PH.D. E. ERIC KNUDSEN, M.S, FUNDED BY UNITED STATES ARMY CORPS OF ENGINEERS LOUISIANA DEPARTMENT OF NATURAL RESOURCES LOUISIANA STATE UNIVERSITY AGRICULTURAL CENTER LOUISIANA STATE UNIVERSITY COASTAL FISHERIES INSTITUTE UNITED STATES FISH AND WILDLIFE SERVICE LOUISIANA COOPERATIVE FISH AND WILDLIFE RESEARCH UNIT SCHOOL OF FORESTRY, WILDLIFE, AND FISHERIES SH LOUISIANA STATE UNIVERSITY AGRICULTURAL CENTER 365 BATON ROUGE, LOUISIANA 70803-6202 .L8 R64 FEBRUARY 1987 1987 FINAL REPORT SILVER SANDS STATE PARK TABLE 17 BIRD LIST Family:. Specil_s (or _Qen@L21.: Common naMt: Accipitridae Circus cyaneug Northern Harrier Alcedinidee MegactLyle alcyon Belted Kingfisher Anatidae Anas 2latyEhynchos Mallard @Ardeidae Butorides striatus Green Heron Charadriidae Charadrius vociferul Killdeer tolumbidee Zenakda MASZoura Mourning Dove Corvidae Corv brachvrhynchos American Crow .6.-US Corvidee Cya nocitta cristata Blue Jay Falconidae Falco sperveri;us American Kestrel Fringillidee Cgrdinalis cardinalis' Northern Cardinal Fringillidee Carpodecus mexicanps House Finch Fringillidae Melospiza melodia Song Sparrow Fringillidne Spizella_aEborea American Tres Sparrow Hirundinidae Hirundo rustica Barn Swallow Icteridae Agel iphoeniceus Red-winged Blackbird Ictaridae Eu2hLo_us sp. blackbird sp. Icteridae guiscalus auificMla Common Grackle Laridee Lgrus argentatus Herring Gull Laridae Lgrus delawarensis Ring-billed Gull Laridae Lerus Marinus Greater Black-backed Gull Mimidae Mimus Rolyglottos Northern Mockingbird Picidae Cglantes auratus Common Flicker .Scolopacidee Tringa melangleU.Q& Greater.Yellowlegs .5t.urnidae Sturnus vulaaris 'European Starling MAMMAL LIST ,.Cricetidae Ondatrg zibethicWs Muskrat Sciuridae Sciuruj caralinansis Eastern Gray Squirrel *Add: Paridae Porus stricapillus Black-capped Chickadee ,Ys DR. KARL ZRIC TOLOWEN -43- - ENVIRONMENTAL ANALYSIS .J APPENDIX D CONNECTICUT DEPARTMENT OF ENVIRONMENTAL PROTECTION Coastal Management Consistency Review Worksheet 'Supplemental Evaluation for Projects Located Within the Coastal Boundary Refer to coastal management consistency review instructions (attached) for sources of information and instructions for filling out this review worksheet. 1. Descrfption of the Proposed Project A. Briefly describe the-entire project including its location, setting, purpose and component activities (i.e., site alterations and improvements, proposed buildings, type of use, etc.). Drainage improvement project to provide flood protection to residences along and north of East Broadway, west of Surf Ave. and south of Great Creek Marsh consisting of diversion of Great Creek westerly from the existing confluence of the east and west branches to outlet into Long Island Sound near the intersection of East Broadway and the Silver Sands Road. The diversion will be routed through man-made open channel and box culvert with an open channel outlet. The existing Great Creek outlet will be filled. (See Proposed Great Lreek Flood Protection Plan-page27 II. Project Location A. Location Description: as applicable coastal boundary map quad (U.S.G.@_ map quad) Milford location of activity site (including street address, names of roads in vicinity of.site, etc.) Great Creek Marsh, its existing outlet, eastern end of Silver Sands State Park, East Broadway (See Project Setting - page 4 name(s) of waterway(s) on or adjacent to the site Great Creek,.Long Island Sound -2- III. Determination of Coastal Management Policies' Applicability and Consistency. A. Identify any and all coastal use policy categories (as reprinted in CAM Planning Report No. 30, Sections 11-A to II-P) corresponding to all activities and uses associated with the proposed project. COASTAL USE POLICY CATEGORIES COASTAL USE POLICY CATEGORIES X II-A. General Development II-I. Sewer-and Water Lines II-B. Water Dependent Uses II-J. Energy Facilities II-C. Ports and Harbors I'I-K. Fuel, Chemicals & Hazardous Mat X II-D. Coastal Structures and Filling II-L. Transportation X II-E. Dredging and Navigation II-M. Solid Waste II-F. Boating II-N. Dams, Dikes and Reservoirs II-G. Fisheries 11-0. Cultural Resources X II-H. Coastal Recreation & Access II-P. Open Space & Agricultural Lands B. Identify any and all coastal resource policy cat (as reprinted in CAM Planning Report No. 30, Sections I-A to I-N) resources on and adjacent to the proposed site And affected by the proposed activity. RESOURCE POLICY CATEGORIES Adjacent -Affected Not On Site To Site by Activity Applica I-A. General Resources Y Y I-B. Bluffs or Escarpments x I-C. Rocky Shorefronts I-D. Beaches or Dunes x I-E. Intertidal Flats x I-F. Tidal Wetlands x I-G. Freshwater Wetlands/Watercourse x x I-H. Coastal Hazard Areas Flood Hazard x x Erosion Hazard .1 x I-I. Developed Shorefront A x I-J. Islands x T--KShorelands x I-L. Shellfish Concentration Areas x x I-M. Coastal Waters Nearshore Waters Offshore Waters X. Estuarine Embayments T N. Air Resources and Air Qua 71 ty -3- C. Identify any and all government process policies as reprinted in CAM Planning Report No. 30, Sections III-A to III-F for all government pro- cesses associated with the proposed project. GOVERNMENT PROCESS CATEGORIES X III-A. Intergovernmental Coordination of Planning and Regulatory Activities. X III-B. Coordination and Consistency of State Programs,.Projects, Expenditures and Acquisitions. _Z_ III-C. Flooding and Erosion Planning III-D. Dredging and Dredged Material Disposal Planning III-E. Coastal. Related Research III-F. National Interest Facilities and Resources D. Determine if the proposed project is consi-stent with all of the coastal policies within the categories identified in III(A), (8) and (C) above. (List each policy under the appropriate column heading.) Note: If a' pro- ject conflicts with any policy, the project should be modified to reduce or eliminate the conflict. Refer to specific policies as lettered in Planning Report No. 30 within each applicable category (e.g., III-A.A, B, C, etc.)., Not Applicable Consistent Inconsistent to This Project II-A.A II-A.8,C II-D.A,C,E,F II-D.B,D Use Policies II-E.E II-E.A,B,CiD,F I-A.A,B,C,D I-D.B,C I-D.A,D I-E.A,B,C,D I-E.E I-F.Z,E Resource Policies I-F.A,B,D I-H.D,H I-G.A,B I-I.A I-H.A,B,C,E,F,G9-I I-L.A,B,C,D i:N:A:I,C, D III-A.A III-B.E III-B.A,B,C,D Government Process III-C.A Policies -4- IV. Evaluation of the Potential Adverse Impacts of the Project and Description Ff Proposed Methods to Mitigate Adverse Effects. A. Identification of Potential Adverse Impacts. NONE/MINOR MODERATE SIGNIFICANT Tidal Wetlands Beaches X -nes Rocky--Shorefront Tluffs and Escarpments Wildlife X Tinfish X Shellfish X Finclude impacts on habitat, breeding, feeding, nursery areas and migratory rout( Coastal Flooding X Surface Water Drainage X Coastal Water Circulation X Groundwater Quality X Surface Water Quality X Coastal Water Quality X Visual Quality X Other B. Briefly describe and evaluate the potential adverse impacts identified above as moderate or significant and the proposed measures to mitigate any ad- verse impacts. Explain why any remaining adverse impacts were not mitigated The visual impact of erecting timber training walls crossing the existing sandy beach could be considered to 5e moderately signillcant. Mere are,. however, existing structures crossing nearby stretches of beach such as th groins in the State Park and the timber training walls, very similar to those proposed, at the end of Nettleton Ave. A lower profile strucE-ure suc as a twin stone groin would result in significantly greater construction, costs. V Determination Policies: x Consistent Inconsistent Adverse Impacts: X Acceptable Unacceptable Comments: APPENDIX E REVISED COST FIGURES OF APRIL 1984 The following pages provide -a detailed, item by item break- .down of the cost of the Great Creek project as described in this report. The project cost, assuming a bid date of December 1984,, is estimated at $716 995. A description of the work or materials involved in each lin; item is also shown. RECF,jVED JUN22iO Dept. of Environmental Protection Nnning & Coordjroastal Mn&mL FLOOD CONTROL GREAT CREEK SILVER SANDS STATE PARK MILFORD, CONNECTICUT PROJECT BI-T-238C COST ESTIMATE BASIC STAGE APRIL 1984 DIVERSIFIED TECHNOLOGIES CORP. April 18, 1984 COST ESTIMATE Item No. DesctiRtion Unit Estimated Unit Extended Qag@@i t Price Total 1 Mobilization and Demobil- ization LS LS LS $ 7,800. 2 Construction Staking LS LS $6500.00. 6,500. 3 Maintenance and Protection of Traffic LS LS LS 2,000. 4 Uniformed Police HR 160 17.00 HR 2,720. 5 Test Pits EA 7 210.00 EA 1,470. 6 Erosion Control LF 250 2*20 LeF* 550. 7 Dewatering and Trench Protection LS LS LS 191500. 8 Clearing and Grubbing Acre 7.6 100.00 760. 9 Cut Bituminous Pavement LF 60 1.00 L.F. 60. 10 Saw Cut Side Walk LF 10 1.00 L.F. 10. 11 Removal of Bitum- inous Pavement Sp 660 050 SOP* 330. 12 Excavation CY 23567 4.25 C.Y. 100,160. 13 Utility Relocation LS LS 45,000. 14 Concrete Encase- ment CY 3.5 250 875. 15 Concrete for Structures CY 178 213.31 37,970. FLOOD CONTROL-GREAT CREEK SILVER SANDS STATE PARK MILFORD, CONNECTICUT PROJECT BI-T-238C item No. Description Unit Estimated Unit gxtende QuantiEy Frice Total 16 Crushed Stone Bedding CY 879 13.00 CY 11,42 17 16' x 5' Box Culvert LF 260 550. LF 143,00 18 Rip Rap SY 270 25.00 SY 6,75( 19 Chain Link Fence LF 210 15. L.F. 3,15 20 Special Gravel Fill CY 270 7.50 C.Y. 2,025 21 Reset Valve Box EA 2 30.00 EA 60 22 Gravel Subbase SY 200 .75 S.Y. 15C 23 Calcium Chloride -:Ton 0.5 300. Ton 15C 24 Bituminous Con- crete Ton 70 40.00 2,80C 25 Bitimunous Con- crete Lip Curb LF 110 1.50'L.F. 16! 26 Concrete Walk SF 300 3.00 S.F. 90( 27 Topsoil, Fertilize, Seed, Mulch and Lime SY 804 2.00 S.Y. 1,60 28 Bitimunous Con- crete Driveway SF 45@ 15.00 S.F. 67! 29 Reset Manhole or Catch Basin EA 2 250.00 EA 50C 30 Filling in Exist- ing Channel CY 5603 3.00 CY 16,80 31 Planting EA 43 40.00 EA 1,72 32 Metal Manhole Steps Rungs 57 15.00 855 33 Aluminum. Railing FT 254 26.00 6,60 34 Safety Chains EA@ 5 50.00 2SC 35 Aluminum Grating LS LS LS 5,7S 36 Grab Bar EA 2 100. 20C FLOOD CONTROL-GREAT Cr SILVER SANDS STATE PAT MILFORD, CONNECTICUT -2- PROJECT BI-T-238C Item No. Description Unit Estimated tinit Extended Quantity Price Total 37 Sluice Gates EA 2 19500. __39LO00- 38 Flap Gate EA 4 5625. -.22,500. 39 Steinke Tide Gat EA 2 27000. 54,000. 40 Site Lighting LS LS LS 2,645. 41 Timber outlet Channel LS LS LS 99,090. 42 Reconstruct Catch Basins EA 4 250. EA 12000. 43 24" R.C.P. LF 270 26.00 LF 7,020. 44 Removal of Head-. 1 250.00 EA 250. wall EA - - 45 Remove Existina Drainage LF 32 26.00 LF 832. 46 Plug Pipe EA 4 50.00 EA 200. TOTAL 657r793. 5% Contingency 32,890. 4% Escalation for December Bidding 26,312. 716,,995. *12 This item does not include the disposal of excess excavated material, the disposition of which will be decided upon by the State of Connecticut. Attached to this cost estimate-are the outline specifications which correspond to the items in the cost estimate. FLOOD CONTROL-GREAT CREE SILVER SANDS STATE PARK MILFORD, CONNECTICUT PROJECT BI-T-238C GREAT CREEK OUTLINE SPECIFICATIONS 1. Mobilization and Demobilization All work necessary for the movement of personnel and equipment to and from the.project site, and for establishment and removal of all contractor's-field offices, buildings and other facili- ties necessary to the performance of work. 2. Construction Staking The Contractor shall provide and maintain for the periods needed, reference stakes at one hundred (100') foot intervals outside of the slope limits. "Stakes shall be properly marked. Additional stakes to be placed for construction of culverts, gate vault and timber open channel as required. 3. Maintenance and Protection of Traffic The Contractor shall keep all existing highways and sidewalks opened to vehicular and pedestrian traffic according to the standards for control and protection of traffic on construction and maintenance projects within the public right-of-way. The Contractor shall furnisht erect, light and maintain such signs, barricades and warning lights as needed or directed. 4. Uniformed Police The Contractor shall furnish uniformed police to act as traf- ficmen at all locations that proper officials may deem neces- sary. S. Test Pits It may be necessary for the Engineer or Contractor to locate or examine soils, ground water, drains, pipes, rocks, public or private utilities or other obstacles. This work shall consist of the satisfactory removal of all materials, including water within the limits of the test pit. This work shall be done as shown on the drawings or where directed by the Engineer. 6. Erosion Control Special care shall be taken to prevent contamination or mud- dying up or interfering in any way of the stream flow along the line of work. Mo waste matter of any kind will be allowed to discharge into the stream flow or impounded wastes of any ponds or other bodies of water. Staked, baled hay.shall be installed per the standards of the Erosion and Sediment Control Handbook- Connecticut by the United States Department of Agriculture. FLOOD CONTROL-GREAT CRa SILVER SANDS STATE PARK MILFORD, CONNECTICUT PROJECT BI-T-238C 7. Dewatering and Trench Protection The Contractor'shall provide all necessary pumps, dams, drains. ditches, flumes, well points and other means of excluding and removing water from trenches, or other parts of work and for preventing slopes from sliding or caving. 8. Clearing and Grubbing This work shall consist of clearing the land within the limits of construction and appurtenant designated areas which are part of the contract, of treest bushes, iron railings, iron posts, stone walls, rubbish and objectional materials as indicated or directed. This work shall also include the cleaning of the site upon completion of all work. 9. Cut Bituminous Pavemtnt This item shall consist of cutting all bituminous pavement in- cluding streets, drivewaysl sidewalks and curbs to be removed as specified on the plans or as directed by the Engineer, 10. Saw Cut Sidewalks This item shall consist of cutting all concrete as specified on the plans or as directed by the Engineer. 11. Removal of Butuminous Pavement,-Concrete, As2halt Curbs This item shall consist of removing all bituminous pavement, driveways, curbs and sidewalks as specified on the plans or as directed by the Engineer. 12. Excavation for Structures and New Channel This work shall consist of the removal and disposal of all ma- terials necessary for the construction of structures and chan- nel including dredging, backfillingj compacting the backfill and cleaning up the site. This work shall include all neces- sary clearing, grubbing and removing old structures or parts thereof as required, except where the contract includes a se- parate item or items for such work. 13. Utility-Relocation The Contractor's attention is called to the fact that he is ob- ligated to inform all utility companies of his startig date on each ofthe phases of work. Any delays caused due to conflicts with the utility lines shall not be considered as a basis of FLOOD CONTROL-GREAT CREEK SILVER SANDS STATE PARK -2- MILFORD, CONNECTICUT PROJECT BI-T-238C extending the time for completion. All utilities shall be lo- cated and precautions taken to avoid said utilities before com- mencing excavation. The Contractor assumes all' responsibility for damage to the various utility services and all liabilities arising therefrom. 14. Concrete'Encasement Concrete encasement shall be constructed as indicated in the contract plans or as directed by the Engineer of Class "A" con- crete. 15. Concrete for Structures Cement concrete masonry for culverts, headwalls and wingwalls, encasement, gate vault and other work shall be constructed to the designs and dimensions.indicated on the plans and to the lines and grades established by the Engineer with or without reinforcement as required. a) 40000 ready mix b). 60000 rebars 16. Crushed Stone Bedding The Contractor shall furnish and place crushed stone for bed- ding as specified on the plans. 17. Install New 16' x 5' Precast, Reinforced, Concrete Box Culvert This item includes the furnishing and installation of a precast reinforced concrete box culvert as indicated on the drawings. Included in this item is damproofing the exterior surfaces of the culvert walls, the furnishing and installing of headwall sections and openings in the box culvert of the type and size shown on the contract drawings. Membrane waterproofing to the top exterior surface of the culvert shall also be included in this item. 18. Rip Ran Rip rap shall consist of heavy stones used to protect founda- tions and to prevent erosion of embankments placed two (@) feet thick. 19. Chain Link.Fence Furnishing and installing chain link fence at the locations and to the heights shown on the contract drawings. FLOOD CONTROL-GREAT CREE SILVER SANDS STATE PARK MILFORD., CONNECTICUT -3- PROJECT BI-T-238C 20. S2ecial Gravel Fill This material shall be used to replace unsuitable foundation material and elsewhere as indicated on the plans or as ordered by the Engineer. 21. Resetting Valve Box to Grade This item shall consist of the resetting to'grade of-all valve boxes as specified on the plans or as directed by the Engineer. 22. Ten (10) Inch Thick Gravel Subbase for Roadway Work under this item shall be the construction of a subbase for highways, roadsp streets, etc., consisting of gravel on the prepared subgrade conforming to the lines and grades, compacted thickness and types of cross-sections as shown on the contract drawings. This item will: also include all work necessary for the preparation of subgrade prior to the installation of the subgrade. 23. Calcium Chloride for Dust Control This work shall consist of furnishing calcium chloride and spreading it on the subgrade or in other areas of the project under construction for the purpose of allaying dust conditions. 24. Bituminous Concrete Six (6) inch coarse bituminous concrete laid in four (4) .courses of equal depth on ten (10) inch calcium chloride com- pacted, stabilized base of gravel. 25. Bituminous Concrete Lip Curbina Lip curbing shall consist of machine laid bituminous concrete, constructed on pavement to the dimensions and details shown on the plans or as ordered by the Engineer. 26. Concrete Walk This item shall consist of concrete sidewalks either replace- ment or new constructed on a gravel base in the locations and to the dimensions and. details shown, including handicapped ramps. FLOOD CONTROL-GREAT CREEK SILVER SANDS STATE PARK MILFORD, CONNECTICUT -4- PROJECT BI-T-238C 27. Furnish, Place Topsoil, Fertilize, Seed, Milch and Liming and Washout Re2air Furnish all necessary plantst materials, equipment, supplies in connection with filling, loaming, fertilizing and seeding in order to repair washouts as shown in the contract' drawings or as directed by the Engineer. 28. Bituminous Concrete Driveway This item shall consist of construction of an eight (8) inch subbase below three (3) inches of bituminous concrete construc- tion in two (2) equal courses to the details, lines, grades and compacted thickness of the typical driveway cross-section. 29. Reset Manhole or Catch Basins to Grade This item shall consist of the resetting to grade of all man- holes or catch basins specified on the plans or as directed by the Engineer. 30. Filling in of Existing Channel This item shall consist of the scraping, stockpiling and place- ment of previously excavated material to the locationst grades and lines shown on the.contract drawings or as specified by the Engineer. This work will also include the creating of a swale to accept the road drainage from East Broadway and direct it into the new proposed channel. 31. Planting This work shall consist of furnishing and planting trees, shrubs and ground cover of the types and in the locations indi- cated on the landscape or site plans of the contract drawings. 32. Metal Manhole Steps Extended Aluminum with step portion at least sixteen (16) in- ches wide (Neenah Foundry R-1982-W). 33. Aluminum Railing To be 6063 aluminum 1 1/2" rails# 1 1/4" posts with RI-204 ano- dized finish. 34. Safety Chain Use Campbell #4/0 straight link-steel, Use anchor shackle on fixed and closed eye swivel on operating end. FLOOD CONTROL-GREAT CREE, SILVER SANDS STATE PARK MILFORD, CONNECTICUT PROJECT BI-T-238C 35. Aluminum Grating Grating to be aluminum with abrasive surface to carry a minimum uniform load of 875 psf. Without deflecting more than 1/4" in a four (4) foot span. 36. Side Rail Grab Bar Same as aluminum hand railing (a special). 37. Sluice Gates Two (2) gates, each to be 72" wide by 54" high, capable of flush bottom closure. Gates to be cast iron, bronze trimmed, side wedges, stainless steel stem# floor mounted gear operator. Maximum seating head of elevin (11) feet, maximum unseating head of six (6) feet. Gates to be in a tidal environment. Eighteen (18) inch wall thimbles. 38. Flap Gates Four (4) gates, each to be thirty (30) inches wide by thirty (30) inches high. Gates to be wall mounted, utilizing twelve (12) inch wall thimbles. Gates to be cast iron and trimmed for a tidal environment. Provide fifteen (15) feet of operation chain for each gate. 39. Steinke,Tide Gates Two (2) gates, each to cover an operating 72" wide by 54" high. Gates to be mounted at end of 6' by 4 1/2' by 10" long precast box culvert. 40. Side Lighting One (1) twenty (20) foot aluminum pole, one (1) 400 watt mer- cury vapor light. Mount on 18" thick concrete wall between the sluice gates. Power to come from East Broadway. 41. TIMBER OUTLET CHANNEL The Contractor shall construct the timber outlet channel in conformance with the lines, gradest dimensions, materials and details as shown on the Contract drawings and in compliance with these Specifications. Included in the work is grading, excavation and removal of material to the proposed grades. Material for timber piles shall comply with the requirements of Section M.09.02-2 of "D.O.T. For 812,, 1980, except for minimum diameter dimensions which shall be 12 inches butt and 8 inches tip. Material for timber sheet piling shall comply with Section FLOOD CONTROL-GREAT CREEK SILVER SANDS STATE PARK MILFORD, CONNECTICUT PROJECT BI-T-238C M-09.01-1 of "D'.O.T. Form 812, 1980". Time sheet piling shall be treated with wood preservatives in the same manner as re- cuired for timber piles. Splicing of sheet piling will not be allowed. Wales shall conform to the requirements for timber sheet piling and shall be treated with wood preservatives as required for timber piles. , Timber piles and timber sheet piling shall be driven in compli- ance with the applicable parts of Section 7.02 of "D.O.T. Form 812, 1980" and to the requirements of the Contract Documents. Water jets may be allowed to obtain satisfactory penetration when specifically authorized by the Engineer. All jetted piles shall be seated by final driving as directed by the Engineer. Suitable excavated material shall be stockpiled on the east side of the construction area as directed by the Owner. Unsuit- able excavated material will' be deposited in the fill area, 42. Reconstruct Catch Basins or Manholes Reconstruction of catch basins and manholes as specified on the plans or by the Engineer. 43. 24 inch R.C.P. Storm Drain Provide and install 24" R.C.P. Class IV to the lines and grades shown on the plans or as specified. 44. Remove Headwall This item shall include the excavation and removal of an exist- ing headwall shown on the plans and the removal of the debris to an area outside the construction limits suitable for dispo- sal of this material. 45. Remove Existing Drainage This item shall consist of the removasl and propert disposal of all drainage pipes as specified on the plans or as directed. 46. Plug Pipe This item shall include the use of brick and mortar to seal the drainage pipes designated on the plans or as directed. FLOOD CONTROL-GREAT Cr SILVER SANDS STATE PAI MILFORD, CONNECTICUT -7- PROJECT BI-T-238C APPENDIX F NEW NAVIN IMSTER, THUMAY, AUGUST 18, 1983 Redirection of creek urged In report on flood control By PAUL JACKSON . City Engineer John Casey, though discussed in the report. One package Milford Bureau Chief familiar with the blueprints provided had a price tag of $1,232,100, though MEYORD - Redirecting Great by the consulting firm, Said Wednes- estimates are not provided for every Creek westerly is one recommenda- day that be had not yet read the final alternative. Half of them would re- tion of a $501,300 flood control plan draft report. quire ringing part of the am with a advised in a final draft report just On the negative side, the report dike. received by the city's Engineering concedes that "on a short-term basis, Besides flooding, the Diversified Department. the major concern (to the recom- Technology report makes five envi- The report, which Public Works mended plan) would be sedimentation ronmental points based on an investi- Director John Donnelly emphasized and turbidity entering Long bland gation of the creek and state park. is in preliminary discussion stages, Sound during the construction phase." 0 The area previously supported was researched by the Diversified The weighty draft continues: a salt marsh but has been "de- Technology Corp. of North Haven "Creeks and channels will be altered graded" by "human alteration of beginning last March when the state under this alternative, with the exist- normal drainage patterns." The cur- Bureau of Public Works authorized ing channel to the outlet abandoned rent condition poses a "Significant" the $37,000-plus contract. and filled and a new channel cOn- fire hazard and the area could be. The recommended predesign plan str-ucted. come a mosquito breeding ground. also includes making an outlet for "Property improvements can be * 'Even though the salt marsh the creek into Long Island Sound expected in this area when the threat has deteriorated, the proposed flood immediately east of the service road of flooding is minimized. With the work presents an opportunity "for there; channeling; pre-cast concrete improvements, a rise in Property combining flood alleviation with box culverts-, tide gates; manually values can also be expected," accord- environmental Improvements." operated sluice gates; and an exit ing to the draft. channel to the Sound, constructed of The proposed plan might also The marsh, then, could be return- timber piles and wood sheeting. 11greatl enhance" the chance of re- ed to its former condition. y Great Creek, situated in the Silver storing near] y 105 acres of.the drain- 0 If the goal of the drainage Sands neighborhood, routinely floods age basin to a productive salt marsh. project is to restore the saltmarsh during even minor rainstorms. Neigh- The material removed from -the basin vegetation, the removal of sediment hors have complained for years that could be used to cover the landfill, is a key. the flooding destroys their property ,resulting in savings of significant and poses a threat to their lives. amount of dollars," the.report said. Plans to redirect the flow of Currently, the watershed area During the past legislative ses- water entering Great Creek Dear eDcompa 505 acres but will ex- sion, the city received a commitment Wayland Road might consider "the pand to 538 acres when the Silver that the state would overlay and seed apparent toxicity" of that w 'ater. Sands landfill is closed. the landfill and finance construction * The freshwater wetlands sup- The final draft said the recom- of any flood c1mtrols that are ulti- port a "high plant species diversity, merded solution "would provide ade- mately approved. Thus, any savings including many species of value to quate drainage, thus alleviating the would be to the state, Dot Milford. wildlife, and harbor many birds. ftisting flooding problem thus re- The recommended improvements The represent habitat diversity that -ulting in numeynus associated beDe- reprelent only one of 10 packages sb2d be maintained." Fits.- ST ATE OF CONNECTICUT DEPARTMENT OF ENVIRONMENTAL PROTECTION -------------------------------------- NOTICE OF 14EETING GREAT CREEK FLOOD CONTROL PROJECT MILFORD, CONNECTICUT Great Creek, in Milford, is in need of remedial work to reduce damage in the area from flooding during storms. The Dept. of Environmental Protection has been requested to stx@dy causes of flood flows and to provide alternatives for reducing damage from such flows. Accordingly, an informational meeting will be held on Wednesday, September 21, 1983, in Old Central Grammar School, 1 Polizzi Plaza, Milford, starting at 7:30 p.m.. At this meeting, Department staff will present the problem and discuss possible solutions. All interested persons are invited to participate in this meeting. Prior to the meeting, any inquiries should be directed to Mr. Arba A. Roberts, Assistant Director, Water Resources Unit, at 203-566-7244. Dated: September 6, 1983* Stanley J. Commissioner PhOM 165 Caotol Avema Hudord. Conneedw 06106 A. VWuni fWwknrjuwjtw Pmudavor BRIDGEPORT POST, nursday, September 22,1983 .DEP official to push. rechannel plan By CATHERINE CLABBY spr". Post staff writer Various state and federal permits MILFORD - The state official over- DEP: flood control plan must be seci for the work, which is ex- seeing design research of Great Creek pocted to mtore 100 acres of salt marsh flood control proposals -will recommend In the area. that the Department of Environmental The project will be funded with part of Protection pursue a SWI,300 plan that will speed landfill cap the $6.5 million the state Legislature has would rechannel the creek to the west. earmarked for a flood-control project in Benjamin Warner. director of DEP's the area as well as the closing and cap. Water Resources Division. said Wednes- MILFORD - Progress toward work, which could be completed by the of a landfill, on Silver Sands State day he will ask DEP Commissioner Stan- implementing a flood control project in state Department of Public Works or a Val Property. ley Pac to accept the rechanneling plan the Great Creek area will accelerate private contractor. would begin after The plan calls for ffie use of dredge and pursue funding for final design work action on capping a landfill at Silver final design work on the flood-control material from the rechanneling effort to from the state Department of Public Sands State Park, according to a De- project is completed. be used to cap the landfill. -In addition, an Works. Construction may not begin until partment of Environmental Protection Final design work on the proposed improved flow of water is expected to next fall. official. $501,300 Great Creek project is ex- eliminate the stagnant pools in the resi- Warner made his comments following "As tow as this one (the flo"n- pected to take three months, according dential area that last summer turned into a public hearing on the issue attended by trol project) is squared away we can to engineers from the North Haven- an extensive breeding ground for mosqui- more than 35 Silver Sands area residents. based Diversified Technology Corp. toes. city and state officials and representa- proceed with the landfill closure," said who completed the intial design work. The plan, estimated to cost $501,300, Richard Clifford. assistant director of tives from Diversified Technology Corps., state parks and recreation. The only thing that could slow the would connect the east and west branches a North Haven-based engineering firm. project, according to Clifford. are of the creek and rechannel It to the west, "I consider the response of the people the landfill, used by the city at insufficient funds for both the Great east of a service road on Silver Sands to be an affirmative one," said Warner, present to dump treated sludge from Creek proposal and the landfill clo- State Park property. Included would be who told residents early in his presenta- Its sewage treatment plant, is slated to sure. the installation of two tide gates. three tion that his department favored the re- be closed and capped after a flood-con- The state Legislature has appropri- sluice gates. a 310-tool-long enclosed con- channeling plan over other proposals pre- trol project is underway, Clifford said ated $6.5 million for both projects. Clif- crete culvert and a I&Ioot raised lumber pared by Diversified Technology Corp. today. ford said further funding would be channel, 15 to 25 feet wide. "it seems to us to offer the best He said final design work for the sought from existing bonds The state would abandon a culvert al- solution under the circumstances," said landfill closure, completed two years 'authoriyAtions it the projects exceed ready exising off of Blair Street. Warner, who added that the plan will not ago. will require some updating. That that amount. - CATHERINE CLABBY Silver Sands Homeowners' Association eliminate all flooding in the area, which President William Ziebell told state offi- has an extremely low elevation, but will cials he would have preferred an open provide quick drainage where there now audience members on their opinions. 'Me Public Works. who also attend the channel rather than an enlosed culvert at is nearly none. advantages of the plan. he said, are that it meeting. Ely said he does not expec con- the base of the rechanneled creek, as it Other alternatives included a plan to is compatible with pending state projects struction will begin on the project until would serve as a boundry between his repair and expand an existing outlet near at Silver Sands State Park. its cost is next fall. neighborhood and the state park. But Don Blair Street and the taking of some pri- relatively low and all construction could , Ballou, a 'Diversified engineer. said an vate property, the construction of a sys- be limited to state property. State Rep. Timothy Casey. R-Millord, open channel would be impractical be- tem of dikes and the installation of a Final design of the project probably however. said he has had some indication cause it would be easily clogged with stormwater pumping station. will take three months, according to a for Public Works officials that it the sand and could limit access to the beach, Warner decided on his recommenda. Morgan Ely, chief of the Design and Re- application process goes smoothly, con- which is open to all below the high tide tion after taking an informal vote among view division of the state Department of struction could begin as early as next mark. 7RE MILFORD CITEMN. THURSDAY SEPTEMBER 22,1983 Drai"n Plan Set For Great Creek Citizen Staff Reporter very heavy tidal storm." DEP engineer A $501,300 drainage system win be used Arthur Christian said, "There would be a. to check the Great Creek flooding of chance every 10 years of it flooding over streets and homes in the East Broadway East Broadway." Donald Ballou of Diver- area, Director Benjamin Warner of the sified Technologies added, however, the Water Resources Unit of the state Depart- later will flow out in three hours as con- ment of Environmental Protection (DEP) trasted with the present stagnation for announced as 35 residents assembled for a many days. public hearing he conducted in the old Cen- Flow increase Projected tral Grammar School Wednesday night. ies Dr. Murali Atluru, president of Diver- Designed by Diversified Technologi sified- Technologies, said the new outlet Corp. of North Haven, the plan provides will allqw a flow five times greater than for redirecting the creek to the west with a the present outlet between Blair and Tre- new 40-foot channel; a new culvert and mont Streets. He said the plan his firm has outlet to Long Island Sound near the ser- developed "will provide good flushing to )rice road going into the Silver Sands State eliminate water stagnating." Dr. Atluru Park area; and tide and sluice gates. said he found an IBM map that showed a Other alternatives, providing for diking 270-acre salt marsh that's now been dimin- and pumping stations and costing up to shed to 100 acres. $1.2 million, were.discussed but will not be Dr. Karl Tolonen, also of Diversified used. More Discussion Planned Technologies, said, "There will be an en- vironmental improvement. One hundred Warner authorized Diversified acres will revert to the type of salt marsh Technologies to proceed with preparation that was there 100 years ago." of final plans and specifications that will DEP engineer Philip Moreschi said the be needed for bidding and award of a con- plan DEP has chosen "will require no pro- tract for the work. Warner said another perty taking." He said other plans that had public bearing, for mom discussion of the been considered "meant taking homes." final plan, will be scheduled before the pro- ject gets underway next year-. Resident Input He said, the plan DEP has designated as City Engineer John Casey said he en- the one to be used "is the most feasible." dorsed the plan DEP has chosen, with one He described it as "the most practical exception. "I'm concerned about the clos- solution to the problem." Apparently ing of the existing channel," Casey said. referring to the park development, he said The city engineer said he would favor it has "advantages to other future pro- "leaving the existing outlet in addition to jects." the new outlet. " Although this will eliminate the flooding Warner said that and other suggestions the East Broadway area has been getting advanced by the residents attending the three to four times every. year, Warner hearing will be considered in the prepara- said, "it will still be subject to floodinr, in a tion of the final plan. Ifluillimil 3 6668 00001 6099 1