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Coastal Zone information Center SHORE EROSION STUDY TECHNICAL REPORT Yc)F JUN 14 1977 APPENDIX 1 SHORELINE EROSION AND BLUFF STABILITY ALONG LAKE MICHIGAN AND LAKE'SUPERIOR SHORELINES OF WISCONSIN KENOSHA COUNTY A.F. Schneider T. Edil B. Haas FEBRUARY 1977 GB 4595 M5 S5 GB 4S7 9.5 lawo appendix WISCONSIN, COASTAL ZONE MANAGEMENT This report has been prepared through the cooperative efforts of the Wisconsin Geological and Natural History Survey, the University of Wisconsin (Madison, Milwaukee, Parkside and Extension), the Wisconsin Department of Natural Resources and the Office of State Planning and Energy. Assistance was further provided by Owen-Ayers and Associates. This report is being reproduced quickly and in a limited quantity for dissemination to local governments and interested parties. The report will be broadly available when reproduced in the fall of 1977 as an information circular from the Wisconsin Geological and Natural History Survey. Financial assistance for this study has been provided by the Coastal Zone Management Act of 1972 administered by the federal Office of Coastal Zone Management, National Oceanic and Atmospheric Administration. 2 US Department of r7c=- ZONE. NOAA Coastal Servicea cor_"L;@,_ , i___2ary I 'A 2M South Robson Avenue ;@Uf:,K CENTER 9 vhu,@.id@ J%k CT@@ Cberjestan SC 20405-2413. INTRODU This Appendix provides detailed information on sh oreline conditions within much of the county. The order of materials in the Appendix is from south to north. Parts of the shoreline are broken down by reach (see County Map) and geographic section within each reach. There is a text which describes the characteristics of shoreline conditions at the 45- beginning of each reach section. This is accompanied by a map of the whole reach which shows the sections, public perception of erosion ha- zards, shore damage in 1952, short- and long-term recession rates, bluff height, shore protection structures, houses per mile, and boat ramps. Location of geotechnical borings is indicated on the county map at LA the beginning of the Appendix. Logs for geotechnical holes and detailed location maps are given at the end of all of the maps in the reach con- taining that geotechnical site. For each geographic section (one mile long) a map showing the location of shore protection structures which are numbered and described in reports on file with the Department of Natural Resources. Also on the map, locations of measured profiles are shown along the shoreline. A running description of bluff characteris- Ln tics, materials making up the toe of the slope, and beach characteristics 4 is also given. Engineering data such as safety factor, the confidence level on this safety factor, and the distance the slope must retreat to attain a stable slope angle is also given. It should be noted that this distance assumes no wave cutting at the base of the bluff. This dis- tance is referred to,in the text as a stable slope distance. Also in- eluded with each section is a set'-of profiles from the water's edge to the bluff top. These profiles show stratigraphy, slope angles, circles of failure, and calculated safety-factors along the shoreline. The dis- 3 taric:e '6- water-Is also given. The date when the profile was measured is also given. Remember that the bluff profile could have changed since the profiles were measured. The meaning of abbreviations.used in the Appendix is given on this page. For more detailed description of the methods used in compiling the data,,, regional interpretations, and conclusions about the engineering characteristics and types of slope failure taking place refer to the main report (Shoreline.Erosion and Bluff Stability Along Lake Michigan and Lake Superior Shorelines of Wisconsin) available from the State Planning Office and the Wisconsin Geological Natural History Survey. Symbols Used (iised as nouns. and adjectives) b boulders c clay or clayey co coarse f fine 9 gravel m medium P pebbles s sand si silt t till y cobbles t(IA) till name SF Factor of Safety A - unsatisfactory 1.00) B - questionable (1.00-1.25) C -,satisfactory ( 1.25) CL Confidence Level A - high confidence - at borehole B - medium confidence - near borehole, stratigraphy visible C - low confidence --away from borehole, stratigrap4y-questionable SL Stability line - the distance slope must retreat to attain a stable slope angle. This assumes no erosion at toe and unchanged conditions of nature of material and water table. 4 3i 32 CH 3 I Palls PARIS J3 it S M RS L LAKE 30 43 - ----- - -------- 36 u . _ - 0. -I I . ..: io 6 192 REACH 2 P30 ak T I It , V" eno 1-12 sha To RATM@,, a I pleasant ------- - ------ P ra EM jG; MICHIGANI AN IP EA AN,' RAIRIE 30 203 f REACH 1 a I- Tobin 41 94 31 M STATE OF ILUNOIS R-22-f KENOSHA CO. DEPARTMENT OF MAWSPORTArt;@% CIVISM op @= ri AT$ STATE QFM Otm mg SCALE 65;;@Mfus 5 Reach 1 Erosion reach 1 of the Lake Michigan shoreline is located in southern kehbshd Cdiinty@ -in Township 1 North., Range 23 East, The reach is about 41 miles long and extends from the Illinois state line on the south to the Kenosha city limits on- the north; it thus includes the entire stretch of Shor eline lmo-@;n loi@ally as Carol Beach. This 4-21-Mile segment is considered to be the Most critical reach of the entire Lake Michigan coast in terms of shbredamage and recbssioh rates, all reaches ., it has the highest priority of with 'a pdrwimile value of 32. The northernmost half-mile of the reach (in section 8) is ovaied by the Wisconsin tliectric Power Company and is currently unused except by trespassing motorcycle enthusiastsi who have desecrated a beautiful and scientifically valuable area of coastal sand dunes and adjoining natural prairie. Except for this power company property And the Trident Marina development at the extreme south end of the reach., the entire reach is subdivided into residential lots., a fairly high proportion of which are vacant, The density, of houses is thus considerably lower than in some other non-urban segments of the shoreline., but new home construction -was apparent during the swmner of 1976. In contrast., during the past few years a number*of houses,have been destroyed as a result of shoreline recession or have been relo cated in order to prevent their destruction, Beach widths in @each 1 rafigie from 0 to about 110 feet,,. Variations in beach width.over short distances are common throughout the reach, most of 'the changes being controlled by shore protection structures. In one area., for example (in section 32), the beach-widens from 15 feet to 110 feet in less than a quar-6er-mile; at another locality, the width increases from 10 to 100 feet in a still,shorter distance. In both situations virtually no beach is present immediately to the north or south. Man's extensive modification of the shoreline coupled with the effects of shoreline recession are largely responsible for these changes. Natural beach materials everywhere consist mostly of sand with smaller quantities of gravelly constituents (pebbles and small cobbles), The bluff in this reach is low. Typically., it is only 4 or 5 feet high and,nowhere does its height exceed 20 feet. In many places a bluff, as such, does not actually exist, the rise from lake level to the upland surface being nothing more than a gentle beach slope. In other places, however, a distinct bluff is present, generally ranging in height between 5 and 10 feet. The highest bluff occurs in section 17 at the north end of the Carol Beach area adjacent to the power company property., where the bluff is 18-20 feet high (see profile 1, section 17)0 Throughout this entire reach., the bluff is composed of fine- to coarse- grained sand* Genetically., most of the sand is beach sand deposited during a much earlier and higher lake stage, but in some places., particularly where the bluff is higher, the upper part of the bluff is made of dune sand (see profiles 1 and 2, section 17). Thin organic horizons, mostly organic sands, are interbedded with the beach sands at several exposures (see profiles 1 and 2, section 17 and profile 1. section 20). No deposits of till or fine- grained lacustrine deposits were observed in any of the bluff-exposures, Several years ago, before the present period of high lake level came into existence., silty.clay.till was exposed just above lal@e level at the extreme north end of the reach in the middle of section 8 on the Wisconsin Electric Power Company property, A 4i-inch power auger hole drilled in October 1976 at the site of profile 2 in section 20 failed to encounter any till., however,, to a depth of approximately 30 feet'below lake level. Shore protection structures are very abundant -in Reach lo Approximately 175 such structures were identified and described, despite the fact that a single structure a.newly constructed. dolomite rip-rap revetment protects the shqro for the. full half-mile of the.electric company's shoreline at the northern end of the reach, For the remaining 4 miles of the reach., the density of protective structures averages about 42 per mile; in one section alone (section 17) there are nearly 60 individual shore protective devices. This. is undoubtedly the highest density of individual structures along the entire Wiscqnsin coast, Slopejailures in Reach 1, occur mainly through the mechanism of slump, induced by oversteepening. of the bluff face by wave action at the toe.. As aresult, thabluff edge in many places i,s.finely scalloped2 particularly. where sboreprotpetion structures are absent. Sand slides and sandflows do not appear toprosent, a severe probleA2 despite the presence of seep zones within the sand units that compose the bluff (see profile 3, section 17 and profile 2., section 20), The precise causes. of the excessive shoreline erosion rates,, which make this reach.the most critical segment of Vdsconsin's Lake Michigan coast., are difficult to.pinppint. The most important single factor is undoubtedly high lake level., and althou& high lake level accelerates erosion rates along the entire shoreline, it may@simply have a greater effect in Reach 1 than in other reaches, A gently to moderately sloping beach, such as that whi ch characterizes the Carol Beach area,. may be largely or entirely submerged by a rise in lake level of only 1 dr 2 feet, Narrowing-of the beach promotes excessive erosion because stom-wave energy is directed against-the toe of the bluff., rather than being mostly absorbed by the beach itselfo A second factor is undoubtedly the character of the material that composes the bluff (such as it is.). in Reach.le Being wholly unconsolidated and without natural cement to hold the sediment together., the loose sand, grains are readily eroded by high@energy waves that,overrun the narrowed beach-and crash against the base of the upland's Because the bluff is low and therefore does not supply the large quantity of raterial to its base as,in high-bluff areas, the sand is quickly removed from the bluff-base or high-beach environment., thereby, eliminating the presence of a buffer zone against the waves in this environment,, which furthor accelerates the rate of shoreline recession. Another cause of excessive erosion in this reach is the location. of the reach., being just south of the City of Kenosha and its harbor structures, which serve to interrupt the longshore transport of sand along the beach; thus thesand removed from the littoral environment in Reach 1 is not replenished or balanced by an adequate inflow of sand from the north. Furthermore., there is probably little sand supplied to the beach that is derived from the land to the west. Although the upland in this area may be underlain mainly by lacustrine silts, the general absence of streams crossing the upland and entering the lake virtually eliminates the possibility of any significant sand replenishment from this directions 4 40 5 3 3.3 2.7 3 r LF 27 2 .7 PUBLIC PEACEP"WEROSION HAZARDS 3 "ic &*my 1932 SMORE OAMAGF 12 -SURVEy-I_SIo@Wo,IEnvvr0"nq" RECESSION RATES; 13 Lav-*m.aoo U shon.twm-a =010,11-31(in foo/vo 3MORE HEIGHT fintensor I") PIMIECTfON 3? RUCTURS3 HOUSM/AMLE- Nmwban SOAT- RAK" T.IN.,R.23E.,Sec.32 10 .91 k p .83 .81 0 n .73 h m .71 .65 h 1 f k 9 .61 54 NA NA NA .51, 9 32 -.42 e f .41 f .33 3 1 .24 d e -.21 d d -.11 c C c b b 3 b .06 a a a SAFETY FACTOR A-less than 1.00 B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL A-boreholes, .(high confidence) B-near boreholes stratigraphy visible C-no stratigraphy visible (low confidence) T.lN.,R.23E.,Sec._32 BL-UF@ i_stiuct6res b- slumping and c-slump; d-structuie s wave erosion, scalloped scalloped bluff edge bluff edge umping h-stable; e-sl' f-str ures g-slump and wave scalloped structures erosion 6iong bluff edge entire sand, also stretch, wave erosion scalloped of the toe bluff edge iAi'h visible si6mo blocks i@-slbmoj wave Ij-some erosion, k-blufi is *entire bluff erosion of but protected beach sand, in this section' i06 by 6tr-dctures. failing by is.beach sand some slump slump and (very fine to wave erosion coarse),anywhere of toe, protection is scalloped absent, there is bluff edge slump and wave er6sion of toe sand taking place 2. TOE a-concealed b-beach sand c-concealed d-beach sand f'beach sand g-concealed h-concealed i-beach sand j-cohcealed k-beach sand *all toe materials are in place, very' fine to medium beach sand, except where c( cealed by structures 3. BEACH a-no beach b-20 to 40 ft. C-no beach d-30 to 50 ft. sand and sand, some gravel gravel e-no beach f-beach widens g-no beach h-20 to 30 it. steadily 15ft. sand and at north,110 gravel ft. at south of segment, sand and some gravel i-60 to 90 ft. j-no beach k-20 to 40 ft. I-no beach sand and sand and gravel gravel M-20 to.40 ft.. n-100 ft. o-no beach P-10 to 100 ft. sand and sand sand and gravel gravel widens southward q-0 to 5 f t. sand and gravel T.lN.,R-,23E.,Sec.32 120- 12 Prof ile 3 100- 120 ft. to 5 ft -depth sand 80- w A-B 20% vegetation W 60- B-C 0% vegetation LL 40 slumping, scalloped edge 20- A *entire bluff is very fine to coarse bedded beach sand B C 20 40 60 80 100 120 140 160 180 200 220 240 260 280 120- Prof He 2 100- 75 ft. to 5ft. depth sand 80- A-B 5% vegetarion-grass w B-C 0% vegetation 60- w LL 40- slumping 20 see above C I 20 60 80 100 120 140 160 180 2;0 220 240 260 280 120- Profilel 100 1 ee ft. to 5 f t. depth sand and gravel 80- w A-B 0% vegetation W 60- LL 40- 20- slumping see above A B 20 40 60 80. 100 120 140 160 180 200 220 240 260 280 FEET T1 H., R2 3 E..Sec. 32 130- 120- 110- 100- 90 80- :1.- 70;-- LU, uj .60 - U. 50- 3 2 4o- jo- Illinois Line *beach sand,bedded very fine to coarse, 20- correlated throughout bluff 10- -6- T s s 0 1000 2000 3000 4000 50.00 F E E T 14 T.lN.,R.23E.,Sec.29 97 .91 .83 .81 .71 .61 c e 29 .51 NA NA NA .42 .41 h .37 b .31 d e .23 d .21 c .13 b, c 0 7 a b 2 SAFETY FACTOR 4-, 0 A-less than 1.00 B-1.00 to 1.25 C-8,ree'ter than 1.25 CONFIDENCE LEVEL A-boreholes (high conf idence) B-near borehole's stratigraphy visible C-no stratigraphy visible (low confidence) 15 T.lN.,R.23E..Sec.29 ALUFF a-!bqlch sand, b-beach sand c-beach sand d-fairly stable qrod *ing by protected, by slumping bluff is beach slump and structures sand protected wave. action. by structures e-sc4lloped bluff edge, total height 4 to 6 ft., all composed of beach sand -sand is slumping in most areas and also being lost . .:. t . - 1 11, @. @. 1 9 - through wave erosion-swallows also weaken bluff by boring numerous deep holes laterally into bank for nests. Sand is very fine-coarse beach'sand. 2. TOE a-beach sand b- beach sand; c-beach sand mostly con- cealed by structures 3. B,EACH a-le s tha' b-10 to-20 ft. c-no beach d-20 to 35 ft. 5 ft. gravel sand and sand and gravel gravel el-210, ft. sand f-no beach' g-65 ft. sand h-no beach and gravel and some. pebbles 1-40 to 100 ft. j-40 ft. sand k-no beach; 1-25 to 30 ft sand and and cobbles structures sand and gravel, some cobbles present T.lN.,R.23E.,Sec.29 120- 16 Profile ft. to 5 ft. depth 100- so- LLJ LLI 60- LL 40- 20- I f 20 40 60 86 11010 120 140 160 180 200 220 240, 260 2810 120- Prof ile 2 100- 54 ft. to 5 ft. depth gravel 80- A-B 25% vegetation LIJ B-E 0% vegetation 60- LIJ LL 40- 20- entire bluff is sand A B C D E 2 4 66 go 100 120 140 160 180 200 220 240 260 280 120- Profile I 100- 70 ft.to5ft.depth sand So- A-B 20% vegetation LLI B-C 0% vegetation LU 60- LL 40- entire bluff is sand 20- A B c 20 40 66 8'0 100 120 140 160 180 200 220 240 260 280. FEET N.,R.23 E.,Sec.29 130- 120- 110- go- so- 70- LU -Lu 60 - .U. 50_ 2 40- 30- 20- 10- s s I A 0 1000 2000 3000 4000 5000 F E E T 18 T.lN.,R.23E.,Sec.zO t .95 91 .85 q p .75 C .71 m 67. 1 - .61 b k 55 a .51 4 3 120 NA NA N h 2 9 .28 a .21 d .11 .06 02 .0 ko_ SAFEa FACTOR A-less than 1.00 B-1.00 to 1.25 C-greater' than 1.25 CONFIIENCE LEVEL A-boreholes (high Confidence) B-near boreholes Stratigraphy visible C-no stratigraphy visible (low cinfidence) 19 T.lN.,R.23E.,S6c.20 BLUFF al_&nerally b-area of c-groin field, d-sand, 5 ft. high sand, 4 t65 slumping and bluff is failure by ft. high, sloughing, fairly stable slump.;scalloped failure by bluff edge and vegetated edge where not slumping and is scalloped sand protected by k4ave 'erosion from slumps structures where not caused by wave pkotected by erosion of toe struc tures TOE a-toe of bluff i's sandi generally very fine to coarse laminated beach sand, except where concealed by structures 3. BEACH a-no beach b-30 to 40 ft. c-5 to 10 ft. d-no beach sand and sand and some cobbles gravel em-16ps than i-no beach g-16 it. sand h-15 ft, sand 5 -it.. sand and gravel and gravel i-10 to 15 ft. j-no beach k-50 ft sand, 1-no beach sand all structures some pebbles some small beach areas of less than 5 ft. m-20 ft. sand n-less tha'n o-50 to 75 ft. p-20 to 25 ft. and gravel ft. sand sand; some sand and gravel gravel 4-no b'e'Ich t-5 t!o 10 ft. s-no beach t-10 to 15 ft. sand and sand and gravel gravel T.lN.,R.23E.,Sec.20 120- 20 Prof i le 100- ft.to5ft.depth so- W LLJ 60- LL 40- 20- 20 40 60 so 100 120 140 160 180 260 22'0 2410 26'0 2SO 120- Profile2 100- 200ft. to5ft.dep, cobbles so- A-B 0% vegetation W W 60 LL 40- slump scarp 20- seeps slump s B I 20 40 60 80 100 120 140 160 180 2@O 2@O 240, 260 280 120- P .rofile 1 100- 60* f Uo 5 f t.deptl cobbles 80- A-B 0% vegetation W W 60- B-C 5% vegetation LL 40- slump scarp entire bluff is very fine to coarse bedded sand 20- slump 'with some organic materials present in certain layers * dark or'ganic layer-sands AZ@l s -/-----B s B C 20 40 60 so 100 120 140 160 180 200 220 240 26'0 280 F E E T F E: E T w ol co 10 w 0 '0 0 _0 0 0' 0 0 Li M w cn pla rD cn rA I @M T.lN.,R.23E.,Sec.17 22 .96 m n k1 .91 =:f'. 8 6 .81 h 77 9 h 2 71 i f 66 b e 9 .61 f 5 6 9 5 f e is 17 .46 d NA NA NA d 3 e .37 .31 c .23 d 21 .14 C. b b .11 ..06 a a -.01 -a SAFETY FACTOR A-less than 1.00 B-1.00 to 1.25 CIO@ C_'greater than 1.25 CONFIDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy,v visible (low confidence) n kl j i j h i , I h@ g @b @a a a T. 1N. .R2 @E. Sec. 17 1. BLUFF a-minor b-fairly stable c-slumping d-fairly stable slumping; protected,with area scalloped sand structures, bluff edge well vegetated sand e-scalloped f-slumping g-bluff fairly h-mostly concealed bluff edge sand stable;long some sand visible, slumping sand beaches fairly stable with seep @ones in fairly well structures lower part of vegetated profile 3 i@-sand;siuMoing j-concealed' k-sand,slumping I-conceal ed with scalloped dolomite bluff edge structures m-sabd, n-sand-j 20 ft. gc6llooed slumping bluff edge; slumps 2. TOE a:!-bbn'bi@aled by b-sand, c-concealed, d-sand, fine to Vegetatioh slumping or in lawns, struc- coarse layered, and piace,.fine to tures beach,slumped structures medium bedded or in place beach sand e-concealed f-�and, layered, g-concealed, h-sand be.ach structures, vegetation and fill i-concealed;' 'j-concealed, k-sand,slump structures, sand or in place some fill 3. BEACH a-no beach b-15 to 20 ft. c-20 to 30 ft. d-5 to 10 ft. sand and sand;some sand and gravel gravel 3,ravel 9 e-25 to 35 ft. f-less than g-no beach h-less than 30 ft. sand and 40 ft. sand sand and gravel, gravel and gravel narrows toward south to 10 ft. i-no beach j-40 ft. sand k-no beach 1-40 to 50 ft. and gravel primarily sand; some gravel 120-- T.IN.,R231,7.,Sec.17 24 Prof-i le 3 120 ft. to 5 ft. depth cobbles 80- A-B 5% vegetation W 60- B-C 0% vegetation U- 40- sand 20- slump A seeps beach B C 20 40 60 80 100 120 140 160 180 200 220 240 260 2@O 120- Profile 2 100- 65 ft. to5ft-depth sand and gravel 80- A-B 0% vegetation w B-C 5% vegetation w 60@ LL 40- dune sand 20- A organic layers beach sand s B C 20 40 60 80 100 120 140 160 180 200 220 240 260 280 120- Profile I 100- .56ft.to 5 ft.depth sand and gravel 80- A-B 90% vegetation w w 60- B-C 0% vegetation LL 40- scalloped bluff edge A dune sand 20- organic horizon lumped sand dune sand s beach sand @bseach uu.. or gai E@D Cbe acl B 0 d s B C I I I f I 20 40 60 80 100 120 1140@ li@O 180 200 12l 0 2 0 2@O 280 EET F E E@ T @w .86 Ln 0% -4 co 0 w 0 0 0 0 .0 0 0 0 0 0 0 co _r_ "M co m (D m m co -.4.0 0 0 0 L" 0 0 26 T.IN.,R.23E.,S,ec.8 51.01 - .92 -.91 .82 d .81 .73 7 71 b b c 76 3 ;2. .61 .52 00 -,,.51 0 NA NA NA .41 b .31 a a .21 -.01 SAFETY FACTOR A-less than 1.00 B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL A-boreholes (high confide-nce) B-near boreholes stratigraphy visible C-no stratigraphy visible (low confidence) fl7 I Tbb F@c 3 27 T.lN.,R.23E.,Sec.8 BLUFF a-area concealed,by vegetation b-same do-nditions as in a-, and revetment which are sand dunes equal in height to the bluff, bluff height approximately 10 ft. 2. TOE a-bedded dune and beach sands b-concealed, toe covered by revetment total le,ngth of section 3. BEACH a-sand and some b-no beach, new c-50 to 100 ft. d-essentially no gravel accre- revetment(.31) sand beach; few areas tion due to all along here between groins groin on point have some accumu- at beginning lation of sand and of section 17 cobbles, but less than 5 ft. 4. PROFILES-none; the shoreline is concealed with protective structures throughout the entire section. @F E' ET co %0 0 w w 0 0 -4 rl m -4 tA 00 29 Reach 2 Reach 2, in Townships 1 and 2 North, Range 23 East, covers 3 miles of shoreline in central Kenosha County. It is virtually coextensive with the City of Kenosha, extending from the southern end of Southport Park in section 8 northward through the downtown and harbor area to the north end of Lake View (Kennedy) Park in section 30. The entire shoreline is p rotected with stone revetments and other structures, with the exception of short segments of public bathing beaches at Southport and Simons Island Parks. For this reason and also because of the low rank accorded this reach - priority rank number 28 with a per mile value of 4, the only part examined systematically was a half-mile stretch of shoreline at Southport Park. Data on beach conditions and shore protection structures were also obtained at Eichelmann Park in section 5. Except for the bathing beach area, where the beach is 50 to 100 feet wide, no beach is present in the Southport Park segment, The bluff is only 5 to 10 feet high, and both bluff and toe materials are everywhere concealed by a continuous stone revetmento Although materials are not exposed, the bluff is probably composed of sand. The segment is marked by a dozen additional structures, most of which are old groins that are today largely non-functional and in need of repair. Small areas of sand accumulation are found adjacent to one or two of these groinsq but even here the beach is less.than 5 feet wide. The sand beach at Eichelmann Park, in the area -where the coast is oriented northeast-southwest, broadens from 63 feet on the east to 83 feet on tie west. It is protected from eastern and northeastern storm waves by a 650-foot long north-south stone breakwater. South of the beach., 'Where the coast is oriented generally north-south, a 350-foot long poured concrete bulkhead protects the shore. No bluff is present. The graded slope behind the beach is artificial fill; the material behind the sea wall is mostly sand. 30 0 Q, 4 2 1 5.2 ------ . ..... 0 T I." 6,2 6 0 7, 4.8 RDS[3 P bile safety PUBLIC PERCEPTION; EROSION HAZA 2 Pruorery I Environment 1952 SHORE. DAMAGE SURVEY -1 -Sio.000 (1952) RECESSION RATES f8 Lorg-term-approx.too yrs. ShOft-lerm-aporox.10yrsjfin feet/yr.) SHORE HEIGHT (intensof feetj SHORE PROTECTION STRUCTURES - - - - - - - - - - - - - - HOLJSES/MILE4 Nomurban - - - - - - - - - - - - - BOAT RAIPS 31 T.IN.,R.23E.,Sec..8 5.01 .92 -.91 82 d .73 "'.7 __1 71 b b c .63 - .62 .61 00 --.52 0 51 .41 b - .31 a a .21 I@P$ 4@ 4; SAFETY FACTOR A-less than 1.00 B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no stra 'tigraphy visible (low confidence) [7 I Mbb 3 T. IN. R. 2 3E. Sec.8 32 11 BL'UFF_ a-area concealed by vegetation b-same conditions as in a-, and revetment which are sand dunes equal in height to the bluff, bluff height approximately 10 ft. b-concealed ered by revetment total length of section 2. TOE a-bedded dune and beach sands toe cov' 3. BEACH a-sand and some b-no beach, new c-50 to 100 ft. d-essentially no gravel accre- revetment(.11) sand beach; few areas due to all along here between groins groin on point have some accumu- at beginning lation of sand and of section 17 cobbles, but less than 5 ft. PROFILES-none; the shoreline is concealed with protective structures throughout the entire section. T.IN.,R.23E.,Se'c.5 33 b .91 .92 - a .81 a a .71 NA NA NA a@ "(3 40 SAFETY FACTOR A-less.than 1.00 B-1.00 to 1.25 C-greater than 1.25 1. BT,UFF a-graded CONFIDENCE LEVEL no bluff A-boreholes present (high confidence) B-near boreholes 2. TOE a-sand b-artificial stratigraphy visible fill (in C-no stratigraphy back of visible (low beach) confidence) 3. BEACH a-63-83 ft. sand, beach widens westward from 63-83 ft. T-2N.?R.23E.,Sec.30 34 .91 9 d d c f c 51461 b b ICI B 0- 20 d ft. a b (0) .41 .21 61 SAFETY FACTOR c@, A-less than 1.00 B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL A-boreholes (high confidence) B-near borehol'es stratigraphy visible C-no stratigraphy visible (low confidence) 35 b-this area c-16 ft. d-no bluff, 1. tT,UFF a- 5-10 ft. has graded maximum gradual sand and gradual height of slope; appears to be stabilized sloPes;no bluff in maximum bluff. this height -maximum segment, about 4-5 ft. height 2 ft. mostly about 10 ft. sand, stable 2: TOE a-sand,gravel b-no bluff c-sand, some d-no bluff and some sitt artificial interbedded fill, mostly sand 3. BEACH a-no beach b-72 ft. c-85 ft. d-170 ft. e-125 ft. south, sand and sand and sand and beach gravel gravel gravel narrows to Oft. f-215 ft. g-275 ft. sand and sand and gravel gravel *fragments and slabs of precast concrete scattered about on upper part of beach represent remains of old groins. Some slabs now being used as bases for picnic grills,however they are not in original position. T.ZN, Sec. -lu 120- 36 Prof i le 100- f t. to 5 f t. dept h 80- W 60- LL 40- 20- 20 40 66 86 100 120 140 160 180 200 220 240 260 120- m Profile 2 100- ft. to 5ft. depth 80- A-B 90% vegetation w F-D 0% vegetation w 60- U- 40- 20- A @C...D 20 4 6@ 810 :10'0 IiO 140 16'0 IiO 2@O 2@O 24'0 2@O 280 120- Prof i le I 100- f t. to 5 f t. dept h so- lop w A-B 85% vegetation W 60- B-D 0% vegetation LL 40- .20- A B C sand D 26 40 6o s6 100 120 140 160 180 200 220 240 260 280 FEET F E E T w A. 0@ -4 co NO 0 w 0 0 0 0 0 0 0 0 1 0 .0 0 LA 0 0 n w A. 8 Ln 0 0 38 Reach 3 Erosion reach 3 of the Lake Michigan shoreline is located in northern Kenosha and southern Racine Counties, in Toimships 2 and 3 North, Range 23 East. It is one of the longer reaches of the shorelinep having a grid length of exactly 6 miles and an actual shoreline distance of approximately 61L mi-les. Geographically, the reach can be thought of as a suburban coastal 2 corridor that connects the City of Kenosha on the south with the City of Racine on the north. Except for only three or four small areas., including the Torn of Mount Pleasant fire station and park property in sections 28 and 29 near the north end, the entire northern three-fourths of the re ach is subdivided; most of the lots are occupied by single-family residences, but a few are used for apartments and small businesses. Immediately to the south in sections 18 and 19 is the campus of Carthage College,-which extends along the shoreline for a distance of more than one-half mile; the rest of the southern quarter is reserved for recreational use and is the site of Alford and Pennoyer Parks., which together are about 6,000 feet in 1 ength. Reach 3 was ranked as the ninth most critical stretch of WisconsinIs Lake Michigan shoreline, with a per mile value of thirteen,. In view of .the considerable property damage and shoreline recession that is currently taking place throughout much of this reach, it would appear that the reach should be assigned a somewhat higher priority. Beach conditions in this r6ach are extremely variable, Beach width, in particular, exhibits great variability, ranging from complete absence of a beach in many places to the presence of an extensive beach that exceeds 275 feet in width. The most marked change in conditions occurs in section 19 near the south end of the Carthage College campus, approximately 6,000 to 6,500 feet north,of the southern boundary of the reach. North of here the beach generally ranges from 0 to 40 feet wide, the exact width at 39 any given locality being controlled in part by the presence or absence of shore protection structures* Because of the considerable variability and nearly continuous changes in width., it is vixtually impossible to estimate an average beach width; a typical beach, however., would be about 10 to 15 feet wide. Beach materials consist of sand., pebbles., and some cobbles. South of Carthage College, in the Alford and Pennoyer Park areas, the beach widens appreciably, Nowhere is it less than 100 feet wide., except at the very southern end of the reach in section 30.,-where it rapidly narrows to zero, Typically, it is between 100 and 200 feet in width, and in one area it is nearly 300 feet across. The beach materials are mostly sand., with relatively lower amounts of gravelly components than farther north. Much of this wide beach is attributable to the presence of a low., broad beach ridge, which is most distinct in northern Alford Park, pinching out just south of the new (July 1976) dolomite block revetment at the south end of the Carthage campus. The crest of this ridge ranges from 3 to 5 feet above lake level and is generally between 30 and 50 feet from the shoreline; the beach slope is typically 6 or 7 degrees (see profiles 2, 3. and 4,. section 19). West of the crest the ridge drops as much as 6 or 7 feet to the toe of the bluff, which in some places therefore is 2-3 feet below Present lake level. The backslope of the beach ridge nearly everywhere is more than 100 feet wide, with a slope of 2-5 degrees. Thus,, the ridge is paralleled by a linear swale., which is partially filled with water and which supports a marsh-type vegetation. Bluff conditions in this reach are also variable., but unlike beach conditions the changes are more regular or systematic. Although in any given sector of the shoreline the height of the bluff appears to be fairly uniform., bluff height gradually descends from north to south; in the northern part of the reach the bluff is nearly 40 feet high (see profile 4., section 29)., 40 but at the south end it is generally 10 feet or less in height (see profiles 1 and 2. section 30). Whereas the bluff is virtually continuous throughout most of the reach, in the southernmost mile it is distinctly discontinuous, as a result of the upland surface near the shoreline having been narrowed and in places completely removed by normal erosional processes near the mouth of the Pike River. Bluff and toe materials in this reach also exhibit a systematic change from north to south. In the upper part of the reach the lower two-thirds to three-fourths of the bluff is composed of calcareous silty clay till, The till is overlain by interbedded fine sands, silts, and clays of lacustrine origin (see profile 4., section 29; profile 1. section 32; and profiles I and 2, section 5). At two localities in the southern part of Racine County a second unit of silty clay till, about 5 feet thick.,@was observed to rest on the lacustrine sediments near the top of the bluff (see profile 3, section 32). The significance of this upper till and its true relationship to the lower till unit are presently unknown; very probably., however,, it is a tongue extending laterally into the lacustrine sediments from the upper part of the main till body. Nearly one mile south of the Racine-Kenosha County line the lacustrine/till contact descends to lake level., with a corresponding thickening of the lacustrine sediments (see profile 3,, section 5), and thence disappears below lake level to the south. 'Still farther south, some of the lacustrine deposits tend to become more massive in character and also finer grained. A power auger hole drilled at the site of profil-e 4 in section 18 indicated that the lacustrine/till contact here occurs at a depth of about 20 feet below lake level.%e bluff is everywhere capped by fine to coarse .-grained sand deposits, which were probably deposited in a beach environment. At the southern end of the reach, however, the low bluff appears to be composed 41 almost entirely of sand., suggesting that the contact between the sand and the underlying lacustrine sediments has also dipped below modern lake level. .Shoreline protection structures are very abundant in the northern three-fourths of Reach 3. Approximately 180 individual structures were identified and described in the 5--mile segment of shoreline that lies north of Carthage College. These structures consist of a great variety of both shore-parallel and shore-normal devices, as well as earthen and man-made materials used for fill. The Carthage campus is protected by a continuous dolomite rip-raprevetment, South of here,, in Alford and Pennoyer Parks, modern shore protection structures are absent, the only structures being a series of 40!.-year old semi-permeable groins that have been largelydestroyed or buried beneath the broad accretional beach deposits described abov*e, Remna nts of four groins were found within a distance of 500 feet in the wooded area between the south edge of the Carthage campus and the unpaved parking triangle in Alford Park. Only partial concrete foundations of the upper ends of these structures, where they were tied to the toe of the bluff about 150 feet from the present shoreline, are still in place., The upper surface of a fifth groin, made of precast concrete, is present about 800 feet south of this group, about half-way between the shoreline and Sheridan Road. The structure was discovered by probing through the sand; however,, the sand cover was removed from only a small area.. and thus neither the maximum depth, of sand nor the length of the structure that is buried beneath beach deposits are known, A sixth old groin'. also made of precast concrete, can be seen at-the shoreline 500 feet farther south., opposite the north end of the paved parking lot. About 10 feet of the structure is present on the exposed-beach, with the eastern end extending well out into the water. The known.length of the groin is approximately 220 feet,, but most of it is buried by an accumulation 42 of sand in the form of a low beach ridge. The maximum thickness of the sand cover is estimated to be nearly 4 feet. The surface of the groin is also visible on the backslope of the beach ridge, 160 or 170 feet from the shoreline. The foundation of the structure was excavated from here to its upper end near the toe of the bluff below the parking areay where it is buried by 3 feet of sand and gravel. Still another groin, of similar design and material is present still farther south., near the north end of se ction 30. About 45-5o feet of this structure is visible at the shoreline., partly above and partly below lake level. Like the groin to the north, the structure passes beneath accretionary beach deposits estimated to be about 4 feet thick. This groin could not be found on the backslope of the beach ridge, but two large slabs of precast concrete similar in design to those in the groin at the shoreline very probably came from the same structure. Although not in place,, they apparently are not far removed from their original position. Fragments and slabs of old groins are scattered about the upper part of the beach in Pennoyer Park, Some are currently being used as bases for picnic grills, The remains of only one structure appear to be in pl ace; at the south end of the park part of a groin can be seen beneath the newly. constructed dolomite block revetment that extends southward along the shoreline of Lake View Park. The evidence afforded by the extensive beach in sections 19 and 30, a beach that is 100 to 300 feet wide and more than 11 miles long, and by 4 these old groins, buried in places by at least 4 feet of sand., is both convincing and conclusive: the southern part of Reach 3 in Alford and Pennoyer Parks has been a zone of major beach accretion for some time., possibly for several decades. 0 43 Except for the Alford and Pennoyer Park areas shoreline recession and slope failure are serious problems throughout the entire reach. Some houses have, in fact, collapsed during the course of the present study and many additional homes situated near the bluff edge are in danger of being destroyed within the near future, Toe erosion bywave action, gully cutting by small streams and by stormywater drainage spilling over the bluff,, rotational and planar motion of small to moderate size slump blocks at the bluff edge, sapping and undercutting within the bluff caused by water issuing from the more permeable layers especially at the contacts between layers of differing permeability within the lacustrine sequence, and mudflows, in the clay-rich till and fine-grained lacustrine sediments are, all active mechahisms of slope failure in this reach. All profiles for Reach 3 north of the beach accretion area in Alford Park illustrate one or more of these conditions. 4 4 2 j, J@7 32 3 % OP, 4 Z 3 3 J- N": Nli '! : I N, ---I -; J9._. , A -:j 2 4 3 Public safety PU13LIC PEnCEPTION:EPOSION HAZA(iPS 2 pforc,ty I Environment 1952 SHORE DAMAGE SURVEY (1952) RECESSION RATES111 Long-lerm-approx.ioc yrs. (in teet/yl 0 Shaft SHORE HEIGHT fintensof feet) T ILL SHORE PROTECTiON STRUCTURES - - - - - - - - - - - - - - HOUSES/MILE- Non-urban 0 - - --- - - - - - - - - - - BOAT RAMPS ME OZ 0 PT xi@j in 0 < rj C.) 01 ITI rh J U) co VV CD 0 tA =r CL Z Co CA r? m m OQ W 1b rt M :10 P1 m rt @- 11 0 0 " 1- o m Go GQ 0 :r m Jv m (D 0 (A 4 0 CL le rt QQ 09 ta. 1-1 1-6 (b @-6z 0 0 0 tr :3 aq 0 :3 Cm P) QQ cr 1-6 m m rt WO in. ;r 1-h 1-4 0 N Co 4% 01 co 46 University of Wisconsin--Extension Geological and Natural History Survey 1815 University Avenue, Madison, Wisconsin 53703 LOCATION AND MONUMENTATION SKETCHES (A B r- i' A 1- -5- Q-tt-, (:@ Q a @It oring.No. 7% ;t A.I. Date Draw 4 -------- - ---------- .6 qraEej.Pit OL Q: FA '558 ACINE CO'.- k[ 0 3 -N '27 ROA 62 72'? T 2 N -"K oWk W 6 4 60 A B070 enos Cou, ry C1 ta Ul An YVILL % R 604 0 he er'..." 3z r" C s S A VJ 0 CA twiT FIRe 6 1 0 Ln 0 Ln C> Ln 0 (D rr Ln to -P"'t rt 6-. 0)0 im. mcl 0 mP rt (D LO rr 9) tij 0 ti rt M W. rt ::r 0 0 m 0 (D0 (D 7V rt (D rt 0 rt m Li :c -'o lb 4-- ED rL rt 0-4 0 w co w 0% P. CL 00 @-A @-A w w ci 0 rt 41- 03 n F-A 0) Ln rt 00 C) 10 n rA ra (D LP Unive rsity of Wisconsin-Extensioh Geological and Natural Hiitory Survey 1815 University Avenue, Madison, Wisconsin 53703 LOCATION AND MONUMENTATION SKETCHES 13oring No. -5#c. Z' Date E 32 3f AVE L A L Drawn by 1'r. T 28 SM 625- Z4 i@@ p 29 j R Y 623 Gravel Pit 4V 619 jvo"UMieJqT AVIe S)+O FAVe - wro-1- -% t:l f-b (D -r-- W W t%3 t) f@ (T, -0 C) Ln c:) Un C) Ln C> Ln rl r? rt ti0 -0 old rt m(A 0 m 0 rt "t PC m 0 H 0 m ti CD0 mPr rtm #I rt 0 m r, m IOA 0 r) rt Q Lo t-h PA LO w I_n co P3 0) co H kD @j :3 :3 03 F-A, 00 0 F- C) @I-a 01 cn C-J :1 FA- FJ CT %D co @-jr CD 14 4@4 0 FJ C) Wn I-h En 0) 0 M Lp 0 cn to, 61P 50 T.2N-,R.23E.,Sec.30 9 d c f C e C. B 01 b b 20 d 30 ft a a c (0) b .41 100 SAFETY FACTOR I& A.-less than 1.00' B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratig-@aphy visible C-no stratigraphy visible (low confidence) 51 I FT,UFF 5-10 f t. b-this area c-16 ft'. d-no bluf f, a an ri has graded 'Maximum gradual appears to -and gradual height of slope; be stabilized slopes;nb bluff in maximum bluff. this height -maximum segment,, about 4-5 ft. height 2 ft. mostly about ft. sand, stable 2: TOE a-sand,gravel b-no bluff c-sand, some d-no bluff and some silt artificial interbedded fill, mostly sand 3. BEACH a-no beach b-72 ft. c-85 ft. d-170 ft. e-125 ft. south, sand and sand and sand.and beach. gravel gravel gravel narrows to Oft. f-215 ft. g-275 ft. sand and sand and gravel gravel *fragments and stabs of precast concrete scattered about on upper part of beach represent remains of old groins. Some stabs now being used as bases for picnic grills,however they are not in original position. 120- Prof i le 100- 1 t. to 5 f t, dept h so- LLJ LLJ 60- Lj- 40- 20- 20 40 66 86 100 120 140 160 180 200 220 2410 260 280 120- m Profile 2 100- ft. to 5ft., depth 80- A-B 90% vegetation LIJ 60- B-D 0% vegetation LLI LL 40- 20 A 210 4 66 8'0 10'0 12'0 14'0 11@0 18'0 2@O 2@O 240 260 280 120- Pro .file i 100- ft.to 5 ft.depth 80- uj A-B 85% vegetation Uj 60- B-D 0% 'Vegetation LL 40- 20- A B c sand D 20 40 60 80 .100 120 140 190 11@0 260 2216 24'0 260 280 FEET L SL N.9 R.23E. I Sec. 30 130- 120- 110- 100- 90- 80- 70- Cfl 60 - L& 2 50- 40- Mouth of Pike River 30- 20- Ir 10- s 0 1000 2000 3000 4000 5000 F E E T 54 T.2N.,R.23E.,Sec.19 9 0- 9 .81 26ft, f B e f h SF=.46+ =top retreat 2.18 e 9 f 2 e .53 d 19 .52 d 3 - C - .51 0- c c 20ft .311 (0) C B .21 b b b a a a SAFETY FACTOR A-less that 1.00 B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy visible (low confidence) 55 I.BUFF a-no bluff b-grassed; c-no bluff d-stable; well e-slump gentle reasonably vegetated, area,bluff slope stable materials partially upward 'concealed graded f-relatively g-no bluff; stable in graded slope most places; for building vegetated, bluff partially graded 2 TOE a-no bluff b-tand c-no bluff d-sand and e-mostly coarse covered silt f-pinkish g-concealed brown lacustrin6 clay 3. BEACH a-275 it. b-188 ft. c-194 ft. d-151 ft. e-140 ft. sand and sand, some sand, some sand and sand.and some gravel gravel gravel gravel some gravel f-110 ft. g-20-100 ft. h-no beach; sand and sand and beach some g Iravel gravel concealed by new dolomite revetment now under construction. 4. STRUCTURES 282-b see map supplement for description Z IV, - be C. L V 120- 56 Prof i le 3 100- ft..to.5. f t-depth 80- Backslope height W A-B vegetati6n 910% W 60- B-C vegetation 50% LL C-D vegetation 0% 40- Bluff A Swale'-Marsh grass Backslope 20- @B 20 40 60 86 100 120 120- Ion 'T LL Ui 7z U_ 4 20- 100 120 140 '160 180 200 220. 240 260 280 FEET 57 T.2N.,R.23E.,SEc.19 120- Prof ile 100- ft. to 5 ft. depth 80- W. W 60- LL 40- 20- 20 40 60 86 100 120 140 160 180 200 22 0 2410 260 280 120- Prof i le 100- ft. to5ft.depth 80- LIJ 60- w LL 40- 20- 26 4 66 80 100 120 140 160 180 200 220 240 260 280 120- Profile 4 100- ft.to 5 ft.depth so- A-P 90% vegetation w B--C 5% vegetation Uj 60, C-E 0% vegetation LL 40- Bluff 20- A Swale-backslope 20 40 60 so 100, 120 140 160 180 200 220 240 260 280 FEET t 2 N., R.23 E.,Sec. 19 UO - 120- 100- 90- so- 70- OD LU Lu 60 - L& 4 3 2 so- 0 0 0 40- rt rt rr rt rr C? .30- M-'Cos 20- fs seep S i Ae�PL 10- c 0 i0oo 2000 3000 4000 5000 T.2N.,R.23E.,SecJ8 59 -.93 CD -.91 87 f f .72 .71 -.63 e c e -.61 1-.53 is NA NA 47 d d 41 c .33 .31 b b .24 - .21 b -.14 .11 a .01 a SAFETY FACTOR A-less than 1.00 B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no-stratigraphy visible (low confidence) 60 T-ZN.,R.23E.,Se.c.l8 I.BLUFF a-scalloped b-mostly con- c-slumping d-fairly stable bluff edge, cealed, some in lacus- grassed area lacustrine slump areas trine,silts silt-many in lacustrine places concealed silts with fill and debris,slump blocks along here in many places e-scalloped d-lacustrine bluff edge silts with bluff here 25- sand on top 30 ft. high- (2 ft.), planar and slumping- rotational scalloped slump blocks bluff edge in lacustrine silts @2. TOE a-either con- b-concealed c-lacustrine cealed or silts mostly lacustrine in place sediments in some slumped place or slumped 3. BEACH a-less than b-no beach c-10 to 15 ft. d-no beach 5 ft., sand and cobbles gravel e-less than f-O to 5 ft. 20 ft.,sand sand and and gravel gravel mostly less than gravel and 40 ft. in cobbles places and toward south 25 to 30 ft. end of area in others. T.2N.,R.25E.,Sec*l8 120- 61 Prof i le 3 100- 40 ft.to5ft.depth sand and gravel 80- W A-B 0% vegetation W 60- B-C 2% vegetation LL D-E 0% vegetation 40- slump scarp s s Oc- 20- B seep zones D seeps si,c E 20 40 60 80 160 120 140 160 180 200 220 240 260 280 120- Profile 2 100- 65 ft. to5ft.depth sand and gravel 80- Stratigraphy f-ms A-B 5% vegetation W c1si B-C 20% vegetation W 60- f-ms C-D 60% vegeta -tion LL si/c D-E 0% vegetation si,c 40- si/c csi A slump scarp seeps 20- - -MeTM si,c - B slump unit seeps C si/c D E 20 40 60 80 100 120 140 160 180 200 220 240 260 280 120- Profile 1 100- 60 f Uo 5 f t.depth sand and gravel 80- lop Stratigraphy W S. A-B 5% vegetation W 60- c B-C 10% vegetation U- si,c C-D 5% vegetation si D-E 0% vegetation 40- A slump scarp --- Eeeps 20- s i'z- L seeps throughout lower k of bluff E 20 40 60 80 100 120 140 160 180 200 220 240 260 280 FEET T.2N.,R.23E.,Sec.18 120- 62 Prof He 4 100- ft. to 5 ft -depth 80- low. w W 60- U_ 40- 20- r 20 40 60 80 100 120 140 160 180 200 220 240 .260 280 120- Prof He 100- ft. to5ft..depth 80- .w 60- w .LL 40- 20- 26 4 66 80 100 120 140 1160 180 200 220 240 260 280 120- Profile 4 100- 40 ft.to, 5 ft.depth Stratigraphy cobbles f-ms,p 80- 's i,c. C/si A-B 5% vegetation w s 1, C. w 60- B-C 10% vegetation U_ C-D 5% vegetation 40- A slump scarp seeps 20- Si,c C/si C seeps D si,c 20 40 60 80 100 120 140 160 180 200 220 240 2@O 2@O FEET t 2 N., R. 2 3 E.,Sec. 18 130- 120- 110- 100- 90- 3 80- 70 - a) LU 60- IA. 50- 40- 30- MS 9 ms g- MS29 ms 29 si/c seeps -c seeps seeps ms g 20- si/C '@Oc seeps si,c c c si,c __.@eeps 10- see PS seeps s i/c -[I si/c --Sae U q__ si/c 1000 2000 3000 4000 5000 F E E T T.2N.,R.23E.,Sec.8 64 .96 q .91 less k B tha p B 10" top retreat) SF, ft. 0 81 h .74, n C=3 .71 20 .68 ft. 9 m h .61 k f _51 9 .42. .41 f 2 .35 A -,T-S@-I e h _4' I B e .3 0- 2 4 20 d d ft. 9 .21 C -.14. e 3 .11 b b d r7I B A c .04 a a b a .01 410 SAFETY FACTOR A-less than 1.00 C113 B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy.visible C-no stratigraphy visible (low confidence) 65 1. BLUFF a-concealed b-some toe C-fill;, d-till.at toe e-filled; fill piled erosion, but slumped bluff concrete, on slopes considerable failing by debris,.some vegetation- slump and toe slumping much fill erosion f-slumping; g-fairly h-planar i-graded; j-lacustrine lacustrine stable; slump- eroding from silt and clay sediments, vegetated previously runoff slump area, planar graded blutt slump,sand scalloped, at top of seep zones bluff in silt k-;Iacustrine I-bluff slumping silts with in places, seep zones; dangerous bluff materials scalloped, piled on Slumps slope 2. TOE a-concealed, b-concealed c-slumped d-.ti-Il,in e-lacustrine some lacus- in some fill place silts,clays, trine sediment areas in place and visible lacustrine Slump silts and clay f-concealed, -g-lacustrine h-lacustrine i-lacustrine j-concealed vegetated silts and sediments sediments bluff clays and fill silts and materials clays and sand either in place or slumped T.2N.,R.23E.,Sec.8 3. BEACH a-10-15 ft. b- 5-10 ft. c- -20 ft. d-5-10 ft. e- -5 ft. @sand and sand and sand and sand and sand and gravel gravel gravel gravel 'gravel f- -20 ft. g-no beach h- -20 ft. i-5-10 ft. j- -20 ft. sand and sand and' sand and sand and gravel gravel, some gravel gravel small areas -.:LO ft. k-5-10 ft. I- --2D ft. m-no beach n- -20 ft. 0-.no beach sand and sand and sand and gravel gravel gravel p- +20 ft. q-no beach sand and gravel 120- 66 Prof.i le 3 100- [email protected] 80- w A-B 0% vegetation W 60- B-D 50% vegetation U- D-E 0% vegetation 40- s slump scarp C'si/si e-p-p-s-- SF=.82 20- -slump blocks si seeps beach 20 40 60 80 100 120 140 160 180 200 220 240 260 280 120- Profile 2 100- ft. to 5 ft. depth 80- A-B 60% vegetation w w 60- B-C 40% vegetation LL SF=.94 C-D 0% vegetation 40- carp C II /seep 20- seeps lump block si,c upps beachD 20 40 60 80 100 '120 140 160 1 0 200 220 240 260 280 120- Profile I 100- ft.to 5 f t.depth so- w w 60- A-C 30% vegetation UL C-D 0% vegetation SF=.94 40- SF=1.05 - s 9 9 -pap Slump/Icarp c --- -Z see'Ps 20- si/vfs seeps slump blocks @= * @14 _A carp c,T 1 A ee p s eepS lump S1., C@ S --CUbeUa Ch SF=" 05 slump@ carp s e s seeps slump b beac D 20 40 810 10'0 120 140 160 180 200 220 2.40 260 280 FEET T. 2 N., R. 2 3 E.,Sec. 8 130- 120- 110- 100- 90- 80-1 70 - 3 2 LU LU 60 - L6 50- 40- 30- s s C'si/ -si 20- sipc vfs si 10- 0 1000 2000 3000 4000 5000 F E E T T.2N.,R.23E.,Sec.5 68 (.-.94 9 .91 20- .84 50 9 ft. - f h 81 'A A 73 f e iSi= . 471 9 +.59 _.63 e f d .61 d .55 51 10 20 .43 f t'. 41 A A C c d FS 7TI61 b .26 b c .21 A- A b ..15 10- W= 7 20 571 ft. a a a, .05 .01 sv. "'o"- 101j' COO SAFETY FACTOR A-less than 1.00 B-1.00 to 1.25 C-greaterIthan 1.25 CONFIDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy visible (low confidence) 69 1. BLUFF a-severe b-fairly c-severe d-slope piled e-g'raded bluff rotational stable; 'rotational with debris; and planar vegetated, slump, wave failing by slump- toe lawns,etc. erosion slump erosion (waves) and slides and flows, scalloped bluff edge f-moderate g-relatively to severe stable, planar vegetated slump and terraced 2. TOE a-till b-unobservable;c-till,in d-mostly e-till overlain by lawns,etc. place,some unobservable; lacustrine slump also where sediment, visible, toe some slump, is till some in -place f-unobservable;g-till, in stuctures place and graded lawns 3. BEACH a- -5 ft. b-0-5 ft. c-20-40 ft. d-15-20 ft. e-5-15 ft. sand and gravel sand and sand and cobbles and gravel gravel gravel gravel f- -5 ft. g-10-15 ft. h-no beach cobbles, .pebbles gravel, and-gravel mostly no beach 120- 70 T.2N.,R.23E.,Sec.5 Prof i le 3 100- ft.to5 ft-depth 80- F- LU LLI 60- A-B 5% vegetation LL 40@ A SF=.57 f pr inenttseep zone 10- see s si'fs'c wt B 20. 40 60 80 100 11210 11410 160 180 200 220 240 260 280 120- Prof i I e2 100- ft. to5ft.deptl 80- F- A-B 50% vegetation LLJ 60- B-C 50% vegetation, w C- D 40% vegetation LL D-- E 07. vegetation 40- A seeps s B S i /V f s P S SF=.72 .1 20- p blocks wt D E -beach I I I I I I I f 20 4 66 80 100 120 140 160 180 2@O 2@O 240 260 2 0 120- Profile 1 100- ft.to 5 ft.depth 80- A-B 0% vegetation LLJ B-C 5% vegetation LLj 60- C-D 0% vegetation LL D-E 0% vegetation SF=.47 40- A--r-r-o-Z"inent sand seeps S seeps vfs 7- SF=.59 20- slump blocks wt C om s e-e L, fs c w B E-beach 20 40 60 80 100 120 160 180 200 220 240 260 280 FE E T T.2 N..R.23E.,Sec.5 130- 120- 110- 100- 90- 80- 1_70- -4 W 3 2 Lu 60 - 50- 40- s 30- 9 P- seep prominent -s-17-cT_seeps �@ep@s vfs sijc seep AV rvrs zone A 20- A. si/vf 4,:9 4 A -wt .4 vfs/ 4 wt*l - -r--: A c 10 - A A A f @b V-ne v V, A, AV Ad t Ji 0 1000 2000 3000 4000 5000 F E E T T.3N.,R.23E.,Sec.32 72 .93 .91 10- 1 n .83 20 ft. 0 A .81 n k .75 m .71 SF=.64 .63 k .61 m L .55 2 SF=.49 I h 32 h <-- .51 45 9 9 f f .41 h SF=.41 .31 e A B e 10- 9 .23 20 f ft.. d e d <-- .21 d .12 c c b .11 b 1--.07 c a ab a .01 SAFETY FACTOR Colo A-less than 1.00 B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy visible (low confidence) 73 TAN.,R.23E.,Sec.32 1. BLUFF a-slump, h-stable, C-seable, d-large slump rotational graded, vegetated block (planar) and planar terraced scalloped bluff edge e-rubbish f-graded, g-severe h-severe strewn on stable with slump erosion by slope, large seawall (planar),also slump,seeps dangerous by debris in lacustrine fall silts,sand, scalloped bluff edge stable, I-filled i-seeps, j- k-filled failure by small old slide and slumps flow,till, scalloped bluff edge m-stable vegetated n-till and o-failing p-till, filled le.custrine here, slump concrete, soils at slides earth, bricks, very top, debris, some some sand and unobservable gravel, spring scalloped midway up bluff,slump, slope* slides and flow tongues 2. TOE a-till or b-graded, c-till and d-till,slumped slump concealed slump lacustrine (sand) sediments or till e-till or f-till, g-concealed h-fill,debris slump slump i-concealed j-till k-till I-mostly fill, some till visible 3. BEACH a-no beach b-greater c-5 to 10 ft. d-less than than 20 ft. sand and 5 ft.,sand gravel gravel and gravel e-15 to 20 ft., f-less than g-greater than h-10 to 15 ft., sand and 5 ft.,sand 20 ft.,sand sand and gravel and gravel gravel i-no beach j-greater than k-20 ft.,sand -1---Oto 15 ft., 20 ft.,sand and gravel sand and and gravel gravel m-10 to 15 ft., n-no beach sand and gravel 74 T. -IN. K. ZJ E, Sec. -Iz 120- Profile 3 ft.to5ft.depth 100- 80- A-F 0% vegetation w B-C 5% vegetation LLJ 60- C-D 0% vegetation LL 40- SF=.41 s slump scarp wt-- - 1 20- si,Vf -se-ep- B wt slump si vfs C D beach 20 40 60 80 100 120 140 160 180 200 220 240 260 280 120- Profile 2 ft. to5ft-deptl 100- 80- A-B 0% vegetation V w 60- B-C 10% vegetation w C-D 0% vegetation LL 40- s A slump scarp g B SF=.49 20- s I ump, wt C beach D 20 40 66 80 100 120 140 160 '180 200 220 240. 260 2810 120- Profile. I ft.to 5 ft.depth 100- stratigraphy s 80- 9 SF=.64 A-B 20% vegetation w 60- si, vfs w wt B-C 40% vegetation LL C-E 0% vegetation 40- slump scarp major seep 20- odified slump bl-ocks si' vfs wt 7 s :-: s um sl,VN! 7@ -s -ep wt C si,vfs mp scar' SF=. 49 SIL c @Cubea h <slump sCca p i@__ _;;a j 0 r seep 0di @D beach D T- 20 40 60 80 100, 120 ;140 160 IW 200 220 240 2@O 2@O FEET - L3 W.,R.23 E.,Sec. 32 130- .120- 110- 100- 90- 80- l..70- 3 2 uJ 60 - 50- 40- @-g s major 30- s seeps wt 9- major sl 20- vf& seeps wta 99 4 V 10- s AbqQ. -7 0 1000 2000 3000 4000 5000 F E E 76 T.3N.,R.23E.,Sec.28/29 .92 f .91 0- I B ft. d f e SF=.54 e SF=. 6 7 20- A' 50 28 .62 ft. .61 SF=.56 d d .53 c .51 c .31 .22 c GT-10 A A SF=.63 20- 21 50 b 12 ft. b b .11 .09 a a a .01 SAFETY FACTOR A-less than 1.00 B-1.00 to 1.25 C-greater than 1.25 CONFIDENCE LEVEL A-boreholes (high confidence) B-near boreholes stratigraphy visible C-no stratigraphy vLsible (low confidence) 77 T.3N.,R.23E.,Sec.28/29 I..-.BLUFF a-failure by b-bluff c-serious slope i-artificial slump consists of failure caused flill;slope recent by slump, in back of artificial debris flow; revetment fill. also by the is vegetated erosion, and appears surface water stabilized. coming over top of bluff, water issuing from seep zones in silt and sands above till. Foundations undercut and exposed. Scall oped bluff margin., slump scarps at top of bluff. TOE a-natural toe b-toe material c-dolomite J-natural toe material is consists blocks material is till, mostly of (revetment), clayey till, covered in artificial with till till covered most places fill and behind in many places by slump or debris dumped by slag (at artificial over top of northern end), fill debris. bluff (broken broken concrete, concrete,slag, dolomite blocks iron,bicycles, and various kitchen sinks) types of debris e-dolomite f-sheet-steel blocks piling (revetment) (bulkhead) 3. BF_%CH a-0 to 5 ft., b-5 to 10 ft.2 c-no beach 1-0 to 8 ft., cobbles and pebbles and gravel,broken pebbles cobbles concrete, stone, wood, junk e-5 to 10 ft., f-no beach beach is less than gravel.slag, 5 ft.,slag, bricks,junk pebbles, and iron junk, 78 T.U.,R.23E.,Sec.28 120- Prof i le 3 100- f t. to 5 f t. deptir 80- A-B,10% vegetation LIJ F-C 10% vegetation LLJ 60- LL C-D 1.5% vegetation D-E 0% vegetation SF=.56 sl scarp s A: C B eeps 20 1 si. slump, flow, sli'des wt C D E 20 40 6'0 100 120 .140 160 180 200 220 240 260 120- Profile 2 100- ft. to5ft.depi 80- F- A-B 0.'/. vegetation LLI 60- B-C 5% vegetation LIJ C- 1) 5% vegetation LL D- E 0% vegetation 40- c seeps s s mps s live pinkish la @ed clays C sLumps,riows and s i es 20 SF=.54 wt: E 20 40 60 80 100 120 140 160 180 200 220 240 260 280 120- Profile i stratigraphy 100- fill ft.to 5 ft.deptl' c si so- s-seeps c A-B 0% vegetation LU si B-C 5% vegetation LL) 60- wt C- D 0% vegetation U- SF=.70 D-E 0% vegetation A 40- sL ump--@a r S carp B seeps rZse ps C SF 20- slump flow C 7@< D E no beach 20 40 60 so 100 120 140 1@0 18'0 200 220 240 260 2 0 zjE. , bec. it, --&, 79 120- Prof ile 100- ft.. to 5 f t.depth so- w W 60- LL 40- 20- 20 40 60 80 100 120 140 160 180 200 220 240 260 .120- Prof ile 100- ft.' to5ft. depth 80- F_ w 60- w U_ 40- 20- 210 4 66 80 100 120 140 160 180 200 220 240 260 280 120- Prof i le 4 100- ft.to 5 ft.depth 80- A-B 0% vegetation w B-C 10% vegetation W 60- C- D60% vegetation U_ SF=.63 ri- E 0% vegetation A 40- f-cos _T_ s I u6p scarp-seep zone s/si7._c___ --- seeps and organic layer majo7seeps si 20- slump+flow wt D dolomite block 'revetment 20 '4'0 6'0 80 100 120 140 160 180 200 220 240 260 280- F F FT t 3 N.,R.23 E.,Sec-28 130-- --120- 110- 100- @90- 80- 4 00 1_70- 0 LU Lu 60 - L& so" f ill J. I. Case 40- property* c c seeps S A,@eps SI's si S artificial 30- seeps - Si'S s11 si's seeps- slope; e graded seeps c e c - S'L s,,@e p s si p c sl 20- wt ;it - Wt :W.t 4 1 . .: .,. v . . . . 4 Q 4 10 4 'L "0 5'2 pro per ty; art J_ f J_ cial @@te2 slope. c I- SA g 7c e raded s e c 0 1000 2000 3000 4000 5000 F E E T 4.- -- @ Al )l. - -- --- - I @ 1181111IMNIM @ 1410249