Shoreline development BMP's best management practices for shoreline development activities which encroach in, on, or over Virginia's tidal wetlands, coastal primary sand dunes and beaches, and submerged lands

[From the U.S. Government Printing Office, www.gpo.gov]

Shoreline Development
BMP's

7 d rim

Best Management Practices for Shoreline
Development Activities Which Encroach In, On,
or Over Virginia's Tidal Wetlands, Coastal
Primary Sand Dunes and Beaches, and
Submerged Lands

Produced by the

Virginia Marine Resources Commission
2600 Washington Avenue
Newport News, Virginia 23607

TC224
V8V8
1994 Reprinted June 1994

m C*

"This reprint was funded, in part, by the Virginia Council on the
Environment's Coastal Resources Management Program through
Grant #NA170ZO359-01 of the National Oceanic and Atmospheric
Administration under the Coastal Zone Management Act of 1972 as
amended."

Printed on recycled paper.

Best Management Practices

Table of Contents

Section I. Introduction . . . . . . . . . . . . . . . . . . . . . . . 1

Section IL Shoreline Protection . . . . . . . . . . . . . . . . . . 3
A. General . . . . . . . . . . . . . . . . . . . . . 3
B. Revetments . . . . . . . . ... . . . . . . . . . 7
C. Bulkheads . . . . . . . . . . . . . . . . ... . 12
D. Groins . . . . . . . . . . . . . . . . . . . . . . 19
E. Breakwaters . . . . . . . . . . . . . . . . . . 23

Section III. Boating Facilities . . . . . . . . . . . . . . . . . . . . 27
A. General . . . . . . . . . . . . . . . . . . . . . 27
B. Marinas . . . . .. . . . . . . . . ... . .. . . . . 29
C. Mooring Buoys . . . ... . . . . . . . . . . . . 33

Section VI. Dredging . . . . . . . . . . . . . . . . . . . . . . . . 35
A. General - Mechanical & Hydraulic . . . . . . 35
B. Beach Nourishment . . . . . . . . . .. . . . . 40

Section V. Instream Work . . . . . . . . . . . . . . . . . . . . . 41

Section VI. Glossa7 . . . . . . . . . . . . . . . . . . . . . . . . . 45

Shoreline Development

BestManagement Practices

Section I

Introduction

Th e attractiveness of Virginia's coastal environs for residential,
commercial, recreational and industrial usesfrequently necessi-
tates their physical alteration. Since the passage of Virginia's
Tidal Wetlands Act in 1972, the Virginia Marine Resources Com-
mission has processed over 21,000 applications for proposed
shoreline construction. (Table 1) These applications have in-
cluded projects located within Tidewater involving impacts to
Virginia's tidal wetlands, coastal primary sand dunes, and
throughout the State involving impacts to State-owned
subaqueous lands. The responsibility for regulatory actions
taken on these applications is shared among 34 local Wetland
Boards and the Commission. Ensuring consistency, with regard
to a unified approach to regulatory decision-making, can be

Table 1. Permit Applications.

2500 -----------------------------------------------------------------

C1J LO
LO 00 (D
0)
2000 ------------------------------------------------- -
C\j LO
,f (D
(0 (D

1500 --------------------------------------------- - - - - - -
0 r
0 CO
C\j

01
1000 ----------------------- - ---------- - - - - - - - - - -
LO LO
LO 0)
CO 00
00 LO
@2 Cal)) LO
50q0- - - - LO
LO

0-
72 73 74 75 76 77 78 79 80 81 82 83 84 856 87 88 89 90 91 92

Shoreline Development

difficult in this setting. While the basis for regulatory decisions
can be found in the enabling Code Sections, the purpose behind
a decentralized decision-making process is to provide for local in-
put and site specific considerations that result in decisions that
conform- with stated policies and standards.

Over the years, the Marine Resources Commission has promul-
gate d and adopted several guideline documents to assist regula-
tors and the regulated community alike in understanding the
many issues incorporated into the application review process.
As recently as September 1991, the Virginia Institute of Marine
Science prepared "The Virginia Wetlands Management Hand-
book," a compendium.of these and other resource materials de-
signed to provide a standardized, ready reference for Virginia
Wetland Board mem'bers. In this documimt, we hope to combine
some of the existing resource materials and further amplify
-them i h practical and sound approaches to shoreline develop-.
wit
ment activities.

The concept of incorporating cost-effective cons ervation meas-
ures into project design is not a new onei During the permit
process, a variety of Best Management Practices (BMPs) are
often recommended by the various regulatory and advisory
agencies for specific projects. These measures have the com-
bined effect of helping to ensure project integrity for. the design
.life of the structure while minimizing the potential adverse im-
pacts associated with construction. V%Thile many BMPs exist for
various construction and land use projects, there has not been a
concerted effort to compile and consolidate'existing shoreline
development activities in conjunction with the standard prac-
tices and conditions contained in our respective institutional
memories. It is therefore the purpose of this document to pro-
vide a more comprehensive view of typical BMPs which can be
readily applied to shoreline development projects thereby reduc-
ing both direct and indirect impacts to wetlands, water quality
and marine resources.

Best Management Practices

Section 11

Shoreline Protection

A. General

The coastal shoreline of Virginia, including its bays and
tributaries, is experiencing continued erosion. While detri-
mental to property values and the structures it imperils,
such erosion is a natural geologic process. Erosion stems
from long term changes in sea levef, waves, and1ocal water
level fluctuations that occur during storms. Upland soils be-
come unstable when saturated and the interface between
land and sea provides both the water and the energy to mobi-
lize destabilized sediments. It is nature's relentless effort to
strike an equilibrium in what can be and frequently is a zone
of extremely high energy.

Along lower energy shorelines, it may be possible to counter-
act erosion by non-structual means through the proper plant-
ing and maintenance of a vegetated intertidal zone or marsh
grass fringe. Such methods of controlling shoreline erosion
are generally cost effective when properly applied and tend
to preserve the shoreline equilibrium. Vegetated wetlands
may erode but their ability to establish dense root systems,
trap and accumulate sediments, and baffle wave energy al-
lows them to act as buffers against erosive forces. Also used
in combination with structural shoreline protection such as
breakwaters, marsh plantings help stabilize these sediments
and provide added protection against high energy natural
forces.

The installation of structural shoreline protection generally
tends to disrupt natural forces and drive shorelines away
from the equilibrium state they seek. There are instances,
however, where non-structural methods simply cannot miti-
gate the natural forces and physical characteristics of an
eroding shoreline. In these situations, shor6line hardening is
often viewed as a necessary alternative to retain upland prop-
erty. And while the placement of these structures may

Shoreline Development

reduce the sustained nutrient and sediment input into adja-
cent waters, it is necessary to understand that ground prepa-
ration, installation and maintenance of these structures can
have equally damaging effects on adjacent living resources.

In reviewing shoreline hardening alternatives, it is helpful to
understand the way in which each type of structure interacts
with it's surroundings. This insight will help us determine
which structure offers the most appropriate solution in a
given situation. While it might prove convenient to attempt
to identify every situation which might require an erosion
control measure, it is not the intent of this document to pro-
vide -a decision matrix which will yield only one possible solu-
tion or, recommended structure for a given problem. Rather,
with an understanding of structural design considerations
and an appreciation of the impacts associated with construc-
tion, it may be possible to apply the most appropriate best
management practices which minimize primary and secon-.
dary impacts associated with construction and maximize the
design life of a: given structure.

While the proper application of shoreline structures may
reduce erosion, not all of the, structures identified in this sec-
tion treat erosive forces in the same manner. The construc-
tion of each of these structures involves varying degrees of
primary and.secondary impacts to the surrounding environ-
ment usually in the form of fill or unnecessary sedimentation
due to uncontrolled upland runoff. 1t; may be helpful to visu-
alize a complete shoreline hardening project by examining
three basic components: site preparation, construction, and
post- construction stabilization.

Site Preparation

Site preparation typically refers to land disturbing activities
which occur prior to construction which facilitate access to a
construction site or involve the preparation of proper earthen
foundations for the erosion control measure. This can range
from the removal of deadwood and debris to extensive grad-
ing and sloping of adjacen t upland areas. The Shoreline
Erosion Advisory Service (SEAS) of the Division of Soil and

Best Management Practices

Water Conservation is located in Gloucester Point and pro-
vides free analysis and planning assistance to private land-
owners seeking recommendations to address a shoreline
erosion problem. Wholesale clearing and grading may not be
warranted or necessary. Also it may be advisable to alter up-
land drainage patterns using berms or drains to help abate
the negative effects of upland runoff on shoreline erosion.

Construction

Timing can be a critical factor when preparing for the con-
struction phase of the operation. For large projects, with
linear distances greater than 300 feet, it is preferable to
gradually work along the shoreline doing the necessary grad-
ing, construction and post construction stabilization as you
progress. Projects that do not lend themselves to this ap-
proach should not be allowed to grad e- too far in advance of
the construction phase without applying the proper erosion
control measures to reduce sedimentation in adjacent wet-
lands and over subaqueous land. Smaller projects, where
wholesale clearing is not employed, should take advantage of
the reduced disturbances and access points should be limited
to only those necessary to import construction materials.

Post Construction

Once construction is complete, the denuded areas need to be
stabilized as soon as possible. This can be accomplished
through the proper application of silt barriers and the revege-
tation of denuded areas. The "Virginia Erosion and Sedi-
ment Control Manual," (available through your local govern-
ment or directly from the Department of Conservation and
Recreation, Division of Soil and Water Conservation) pro-
vides information pertaining to the installation and mainte-
nance of soil conservation measures in accordance with State
minimum standards and specifications. Applicants may also
want to check with their local government to determine com-
pliance standards under the local sediment and erosion
control ordinance.

Shoreline Development

Chesapeake Bay Regulations

It is appropriate to mention that all proposed shoreline
erosion control projects must satisfy the "Chesapeake Bay
@Preservation 'Area Designation and Management Regula-
tions." Adopted by the State in September 1989, these regu-
lations contain provisions designed to prevent a net increase
in non-point source pollution. Key to achieving the design
goals are performance standards intended to minimize ero-
sion and sedimentation potential, reduce land application of
nutrients, maximize rainwater infiltration, and ensure long-
term performance of the measures employed.

Section 4.3(B)-l(d) of the regulation provides for the altera-
tion of the mandated buffer for erosion control projects pro-
vided such alteration is accomplished utilizing the best
available technical advice and applicable permit conditions
or requirements. This section does not provide a categorical
exclusion from the Chesapeake Bay Regulations. What it
does is allow encroachment into the buffer area only to the
extent necessary to establish the erosion control measures
given the best available technical advice; This may involve
clearing and grading of an entire reach of shoreline but it
may also involve clearing only that which is necessary to
access the site and install an erosion control structure.

In addition, if the land disturbance involves an area greater
than 2,500 square feet,'Sections 4.2-4 and 4.2-69f the regula-
tion state the -applicant shall submit an erosion and sediment
control plan and shall comply with the requirements of the
local erosion and sediment control ordinance. Again, the
attainment of A wetlands permit does not obviate the need to
comply with this regulation.. It is incumbent upon the prop-
erty owner to find the local representative and ensure compli-
ance with these regulations.

Best Management Practices

B. Revetments

From an environmental perspective, riprap revetments are
generally preferred over bulkheads due in part to their abil-
ity to absorb and dissipate wave energy, thereby reducing
the transfer of these erosive forces to adjoining properties.
The sloped nature of a revetment also provides greater sur-
face area within the intertidal zone than vertical structures.
In addition, open spaces between armor units may provide
suitable habitat for marine organisms and in some cases trap
enough sediment to support wetland vegetation.

A revetment is usually composed of separate layers of stone.
The size of the revetment is determined by the energy of the
environment which will further dictate the composition of
these materials. The construction of larger riprap revet-
ments involves the placement of core material, generally
smaller stone with random shapes and sizes, over filter
fabric which prevents the loss of earth from behind the
structure. The smaller stone acts. to fill in gaps between
larger armor units, shields the fabric from destabilizing ultra-
violet light and'also protects the filter fabric from being torn
when laying the armor stone. This core layer is then covered
with a layer of selected arnior units. Armor units may be
placed in an orderly manner to obtain good wedging or inter-
locking action between individual units or they may be ran-
domly placed. The toe of the structure is usually buried
below the MLW mark in high energy environs to prevent
undercutting. Graded banks which are armored with
smaller stone may not require the use of core material. In
these instances, the armor stone is mixed with core stone
and applied directly over the filter fabric. (Fig. 1, pg. 8) In
general, the dumping of material down embankments with
little or no attention to placement and the use of filter fabric
is not viewed as a practical solution for shoreline erosion.

Designing riprap structures oftentimes requires using known
variables to more accurately determine the necessary size of
stone, height of structure, and depth of toe. These factors are
influenced by the type of material used (unit weight and
stability), site specific wave characteristics (wave height,

Shoreline Development

Figure 1. Riprap Revetment.

Erosion & Sediment
Control Barrier

Eroding Bani--.*--'.-*
Filter Cloth

Graded Bank w/kiprap

period, direction, storm duration and frequency), and design
slope.

Recommended Best Management Practices

1. Construction materials employed typically vary in size
and composition depending on the type of structure, the
physical parameters at the project site and the availability
of material. A publication by the U& Army Corps of Engi-
neers entitled, "Low Cost Shore Protection... A,Property
Owner's Guide," recommends that no individual armor
unit be longer than three times its minimum dimension.
Therefore, if an individual chose to construct a revetment
using slab concrete six inches thick, the material should
be broken such that the average length of the armor mate-
rial isno greater than eighteen (18) inches. The State
Erosion and Sediment Control Field Manual, STD &
SPEC 1.37 describes riprap such that "the stone shall be
hard and angular and of such a quality that it will not dis-
integrate on exposure to water or weathering and it shall
be suitable in all other respects for the purpose intended."
Most if not all of the material-used as riprap in coastal
Virginia is either quarrystone granite, or broken concrete.

Best Management Practices

Riprap can therefore be defined as:

Riprap: Stone that is hard and angular and of such a quality
that it will not disintegrate on exposure to water or weathering
and it shall be suitable in all other respects for the purpose in-
tended. No individual armor unit should be longer than three
times its minimum dimension.

a. Rubble concrete may be used as riprap provided it is
broken into appropriately sized units and exposed
rebar is cut flush with the unit. All asphalt material
must be removed prior to installation.

2. Riprap is sized based on its weight. These weights, per
VDOT specifications, are divided into the following
classes/types (Fig. 2):

a. Class Al - Stone in this class shall weigh between 25
and 75 pounds with no more than 10 percent of the
stones weighing more than 75 pounds. Often referred
to as "man-size."

b. Class I - Stone in this class shall weigh between 50
and 150 pounds with approximately 60 percent of the
stones weighing more than 100 pounds.

c. Class II - Stone in this class shall weigh between 150
and 500 pounds with approximately 50 percent of the
stones weighing more than 300 pounds.

Figure 2. Relative Stone Size.

Shoreline Development

d. Class III - Stone in this class shall weigh between
500 and 1,500 pounds with approximately 50 percent
of the stones weighing more than 900 pounds.

e. T@ype I - Stone in this type shall weigh between 1,500
and 4,000 pounds with an average weight of 2,000
pounds.

f. Type II - Stone in this type shall weigh between
6,000 and 20,000 pounds and have an average weight
of 8,000 pounds.

Note: In all classes/types of riprap, a maximum 10% of the stone
in the mixture may weigh less than the lower end of the range.

Generally speaking, Classes AI and I stone are utilized in more
tranquil creeks and protected shorelines while the remaining
stone is typically used on lower tributaries, the Bay, and the
ocean.

3. The slope of a -revetmen't may vary somewhat depending
on the physical setting and overall size of the proposed
structure but, in general, slopes of 2:1 (2 Horizontal on 1
Vertical) or 3:1 are recommended.

4. All riprap revetments should be constructed using the
proper application of filter cloth. As structures'age and
are exposed to erosive forces, filter cloth will tend to pre-
serve the integrity of the structure by retaining underly-
ing base material. Installing filter cloth initially will
prolong the life of the structure, reduce maintenance costs,
and reduce disturbances to adjacent wetlands caused by
construction activities. Filter- cloth may also.reduce the
frequency with which snakes and other undesirable pests
utilize the revetment by providing a barrier against bur-
rowing into sediments. Filter cloth should be a woven or
nonwoven fabric consisting of continuous chain polymeric
filaments or yarns of polyester. The fabric should be inert

Best Management Practices

to commonly encountered chemicals and be mildew and
rot resistant.

5. Proposed alignments for riprap revetments must be
staked and flagged indicating the channelward limit of
encroachment prior to or concurrent with the submission
of Joint Permit Applications. Stakes should be located a
maximum of 50 feet apart.

6-. As in all shoreline hardening projects, access to a project
site has a great influence on the overall impact of construc-
tion related activities. Direct 'and indirect impacts consid-
ered during project review generally do not take into
account how materials and machinery will access a given
reach of shoreline. The total impact of construction gener-
ally includes a variety of associated incremental impacts
within various ecological zones around a project site. For
this reason, care should be taken in transporting materi-
als to a project site. In situations where armor material
cannot be readily transported to it's ultimate destination,
it is recommended that precautions be taken to minimize
overall project impact.

a. Projects which necessitate the dumping of stone
down natural embankments to stock pile material
should limit dump points to only those absolutely
necessary. Given the core material and site prepara-
tion required, dump points should be limited to one
every 75 to a 100 feet. The use of shoots to confine
loose material may also be useful. Such practices will
tend to reduce slope revegetation requirements and
minimize erosion onto adjacent wetlands.

b. Projects requiring the crossing of wetlands or which
are in close proximity to wetlands, should make use
of mats to minimize construction impacts. While
potentially damaging to the standing crop vegetation,
the purpose of using Tats is to preserve existing

Sh6reline Development

elevations and root composition for sustained viabil-
ity of the wetlands.

7. Following construction, all excess fill material and all dis-
turbed or denuded areas should be graded, seeded and the
proper application of temporary erosion and sediment con-
trol bar riers should be employed to reduce erosion of up-
-land into adjacent wetlands and waters. (Fig. 3)

C. Bulkheads

Bulkheads and seawalls are terms often incorrectly used
interchangeably when referring to shoreline protection struc-
tures. Generally, bulkheads are smaller and less expensive
than massive seawall, structures and are designed to retain
upland soils while providing protection from minimal wave
action. Seawalls on the other hand are designed to with-
stand the full force of waves and are often concrete struc-
tures poured in place.

Figure 3. Erosion and Sediment Control Barrier.

Erosion & Sediment
Control Barrier

MLW.

Best Management Practices

Figure 4a. Sheet Piles (End View).

KZZMN

Ship-lap Tongue & Groove Wakefield

Proper bulkhead design is a function of both the wave
climate in adjoining waters and the physical force placed on
the wall by the weight of the backfill material. Sheet piles
are usually either ship-lap, tongue and groove, or Wakefield
design and are supported in a vertical position by wales.
-(Fig. 4a & 4b) Typical means for burying sheet piles include:
jetting with high pressure water, driving with a pile-driver or
sledge, and trenching and backfilling with trenching equip-
ment. Anchors or deadmen are driven into fastland behind
the bulkhead and connected to the structure with corrosion
resistant tiebacks. These are essential to achieve the design
life of the structure by adding the additional strength neces-
sary to withstand back pressure. Premature bulkhead

Figure 4b. Typical Bulkhead Design.

Sheet
Pile
Deadman

..........

Tie-rod
Weep
Hole

0 OP.
Wale

Filter Cloth

Shoreline Development

failure is often attributable to failure of the tie-back system
through corrosion and/or excessive back pressure. Weep
holes may be used along the face of the structure to help
reduce the back,pressure by providing a means for water to
escape from behind the bulkhead.

How bulkheads respond to wave energy depends on the
structures orientation to the approaching storm waves. Bulk-
heads are not particularly effective at dampening wave en-
ergy. Rather they tend to transfer the wave energy laterally
along the face of the structure or vertically up and, down.
(Fig. 5) In either instance, the cumulative effect is a net loss
of sediment in front of the structure and/or along the sides.
(Fig. 6) Placing a vertical retaining structure landward of
mean high water helps to reduce its exposure to wave action
and thereby minimizes erosion.

Recommended Best Man a*gement Practices

1. Construction materials/methods should include the
following:

a. All wood should be pressure treated to a minimum of
1.5 lbs/ft3 of CCA or a minimum creosote level of 12
3
lbs/ft .

Figure 5. Wave Energy Transfer at Bulkhead Face.

MHW

Wave Energy

MLW
. .........................

Best Management Practices

b. All hardware (bolts, nuts, washers, etc.) should be
galvanized.

c. Filter Cloth should be a woven or nonwoven fabric
consisting of continuous chain polymeric filaments or
yarns of polyester. The fabric should be inert to com-
monly encountered chemicals and be mildew and rot
resistant.

2. All bulkheads should be, constructed using the proper
application of filter cloth. As a structure ages, even a well
constructed bulkhead will settle causing small cracks
which can leak backfill. Installing filter cloth initially,
therefore, can prolong the life of the structure, lower main-
tenance costs, and reduce disturbances to adjacent wet-
lands caused by construction activities.

Figure 6. Shoreline Recession Associated with Bulkheads.

MLW

Shoreline
Recession
'@@Shorcline When Over Time
Bulkheaded

Shoreline Development

3. If the stkucture is equipped with drain holes to allow for
the movement of water, they should be backed with filter
cloth and a small stone filter.

4. Fill material should be free of debris and be a good quality
sandy soil. The use of silty dredged material is discour-
aged since this material drains poorly allowing back pres-
sure buildup behind the bulkhead.

5. In general, the length of the tieback rod should be equal to
or greater than the length of the sheet pile used on the
face of the structure.

6. The depth of sheet pile penetration below existing grade
should be equal to the veitical distance above ground.
This helps reduce structural failure as scour occurs along
th6 face.

7. Deadman should be anchored vertically into fasitland
using either a galvanized rod or cable. (Fig. 7)'The place-
ment of deadmen horizontally in associated fill material is
discouraged.

8. In areas where the topography does not naturally allow for
the proper placement of deadman, the bank should either
be graded back or areas for the location of deadmen exca-
vated out of the bank. (Fig. 8) 'In most cases, it is not

Figure 7. Deadmen.

Upland

Fill

Best Management Practices

Figure 8. Tiebacks.

MLW Bulkhead MHW

Tie-Backs ie-Backs Toe of Slope
Top of Slope

desirable to extend the channelward encroachment of a
structure simply to accommodate prescribed tieback
lengths. Steep high banks may require the use of screw
anchors as deadmen to securely support the bulkhead.

9. In situations where bulkheads are located close to exiting
structures which will not allow for the proper installation
of dea,dmen, the use or application of knee bracing or
buttressing on the seaward side of the bulkhead is rec-
ommended. (Fig. 9) (The use of riprap may be appro-
priate in this setting.)

Figure 9. Knee Bracing.

TV
om"
,jp a I

Shoreline Development

10. Bulkheads should ti,e into adjacent bulkheads or return
walls should extend back into existing fastland'. Where
practical, the'application of riprap along return Walls will
help prevent flanking of the structure.

11. In situations where bulkheads are located in areas suscep-
tible to wave energy, the proper application of appropri-
ately sized riprap toe scour protection may reduce the
likelihood of the structu'ral failure-du e to undermining at
the face. (Fig. 10)

12. Proposed alignments for bulkhead structures should be
staked and flagged to indicate the channelward limit of en-
croachment prior to or concurrent with the submission of a
Joint Permit Application. Stakes should be- located a maxi-
mum (if 50 feet apart and at turning points.

13. Structures should ordinarily be located landward of marsh
vegetation, or- in areas of non-vegetated wet.lands, placed
landward of mean high water to minimize exposure to
wave action.

Figure 10. Scour Protection.

Wave Energy
77@@@

Best Management Practices

Figure 11. Erosion & Sediment Control Barrier.

Erosion & Sediment
Control.Barrier

Flanking
Protectio

V
7..

14. Following construction, all excess fill material and all dis-
turbed or denuded areas should be gFaded, seeded and the
proper application of temporary erosion and sediment con-
trol barriers should be employed to reduce erosion of up-
land into adjacent wetlands and waters.(Fig. 11)

D. Groins

Groins are constructed perpendicular to shore and extend
out channelward from mean high water. Groins function to
trap sand and raise the elevation of the nearshore area to
provide better erosion protection. Material moving along the
shore in the littoral drift normally accumulates in fillets on
the updrift, side of the structure. (Fig. 12) Under ideal

Figure 12. Littoral Drift.

Sediment
Transport Fillet

Shoreline Development

circumstances, sand fills the groin dell to a point where it
then bypasses the structure and continues movement along
the downdrift shoreline. The.sand remaining in the fillet is
then available to function as a buffer against erosion. Yet
even under ideal conditions, material tends to move more
slowly through the filled groin cell thereby depriving down-
drift shorelines of sand and increasing the rate of erosion on
downdrift; property.

Groins are generally only effective when adequate quantities
of material are moving in the littoral transport system. Be-
cause of the potential to damage downdrift properties, it is
often recommended to position groins away from property
lines and to partially fill groin cells with appropriately sized
material. Filling groin cells tends to reduce the time re-
quired for littoral material to st;art bypassing the groin
thereby reducing erosion of downdrift property. Groin spurs
may also be employed to help reduce downdrift erosion.

Recommended Best Management Practices

1. Construction materials/methods include the following:

a. All wood should be pressure-treated to a minimum of
1.5 IbS/ft3 of CCA or a minimum creosote level of 12
lbs/ft3

b. All hardware (bolts, nuts, washers, etc.) should be
galvanized.,

c. If the structure is constructed of stone, the stone
should be placed on a layer of filter cloth to help stabi-
lize the structure.. The size of the stone will be dic-
tated by wave characteristics at the proposed location.

2. Because groins function to trap sediment moving along a
shoreline, their effectiveness is somewhat related to the
amount of material available in the system. For this
reason it is prudent to space these structures such that
the distance between groins is greater than, or equal to,

Best Management Practices

1.5 times the groins length from high water to it's channel-
ward end. Groin length can be determined by examining
the sand fillets in existing groins along the same shoreline,
reach or they can be based on the width of the local beach.
Example: A 40-foot groins should be spaced a minimum of
60 feet apart.

3. All groins should be constructed utilizing a low profile de-
sign. (Fig. 13) The low profile groin is designed to resem-
ble the natural beach elevation and allows sand to by-pass
and thus nourish downstream properties once the groin
cell has filled. Groins which are too long may inhibit the
longshore transport of sand to dowfidrift properties.

Low Profile Groin: Low profile groins are structures with a
terminal elevation at mean low water extending landward to
an elevation of 1 foot above mean high water, at mean high
water, with the landward terminus extending into upland to
reduce flanking.

4. In situations where groins are located in areas accessible
to boaters, it is recommended that the channelward end of
the structure be marked to aid navigation. This can be
simply accomplished by using a longer pile at the termi-
nus and leaving 12 - 24 inches remaining above mean high
water.

5. Proposed alignments for groins should be staked and
flagged indicating the channelward limit of encroachment

Figure 13. Low Profile Groin.

MHw
NI(LW

Flanking ...................... .........
Protection .......V......

Shoreline Development

prior to or concurrent with the submission of a Joint
Permit Application.

6. Groins should be located a minimum of 25 feet from prop-
lines.

T. The application of groin spurs on the downdriftsides of
groins may aid in reducing downdrift scour in the immedi-
ate vicinity of the groin. A spur should be located at ap-
proximately the mean low water mark. (Fig. 14)

8. At times, it may be desirable to artificially fill or nourish
the groin cell to help reduce the amount of time necessary
before sand begins bypassing the structure thereby mini-
mizing the disruption in the supply of sand to downdrijI
properties. Nourishment material should be of a grain
size equal to that of native beach sand and should be con-
toured to approximate the natural sand fillet which forms
on the updrift side of the groin.

Figure 14. Groin Spur.

Fillet

Spur.

........... ...........
@MLW'Q

Riprap'

Best Management Practices

E. Breakwaters

Breakwaters are placed in the water parallel to shore and
Are designed to dissipate wave energy before it reaches ad-
joining shorelines.. This decrease in wave energy reduces the
ability of waves to transport sediment resulting in an area of
sediment deposition behind these structures. A breakwater
system usually addresses erosion over a large area and con-
sists of a series of breakwaters along a reach of shoreline.
(Fig. 15) Sand moving in the littoral transport system accu-
mulates in the shadow of the breakwater until filled to its
natural capacity. Once filled, sand can then move through
the breakwater system to downdrift properties. As with
gpoins, breakwaters can be partially nourished to create
natural bays or tombolos and insure a minimal disruption in
the supply of sand to downdrift properties.

Offshore breakwaters must be constructed of materials capa-
ble of withstanding the high energy environment in which
they are placed. Since the height of the breakwater deter-
mines how much wave energy is dissipated, an important
design consideration rests in maintaining the design height
for the life of the structure. While a variety of materials
have been used in breakwater construction, some degree of
success has been achieved in Virginia using quarrystone

Figure 15. Breakwater System.

Breakwater
Tombolo

MHW

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riprap. These Figure 16a. Gabion Basket
structures are Filled with Quarrystone.
typically rubble
mound or gabion
systems and are
able to with-,
stand the differ-
ential settlement
that may occur
after placement.
(Fig. 16a and
16b)

Breakwaters do
not have univer-'
sal application. The design of a breakwater system must
take into account a variety of site specific considerations in-
cluding wave characteristics, material composition, height
requirements, distance from shore, length, spacing, and
existing shoreline configuration., In addition, equipment and
material access to the site as well'as the potential environ-
mental impact on sensitive submerged habitat must be taken
into account. The Shoreline Erosion Advisory Service is
available to assist in the design of breakwaters, It is
strongly recommended that this type of work be undertaken
by professionals experienced in breakwater construction.

Figure 16b. Rubble Mound and
Gabion Basket Breakwaters (End View).

----------- M14W -----------
- - -----------
TM ----- ----
----------
MLW -----

Best Management Practices

Recommended Best Management Practices

1. A plan of access to the proposed breakwater location
should be developed. This should include precautions
necessary to avoid or minimize impacts to adjoining

resources.

2. A construction time table should be developed so that the
staging and deployment of stone will not be unduly pro-
longed. Gabion baskets should be closed and. sealed once
filled. Partially filled structures should be secured until
the remaining work can be completed.

3. At times, it may be desirable to artificially fill or nourish
behind a breakwater to help reduce the amount of time
necessary before sand begins bypassing the structure.
Nourishment material should be of a grain size equal to
that of native beach sand and should be contoured to
approximate the cuspate shoreline which forms.

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Best Management Practices

Section III

Boating Facilities

A. General

Section 28.2-1203 of the Code of Virginia states that, it shall
be unlawful for any person to build, dump, trespass or en-
croach upon or over, or take or use any materials from the
beds of the bays, ocean, rivers, streams, or creeks which are
the property of the Commonwealth, unless such act is per-
flormed pursuant to a permit.issued by the Marine Resources
Commission .............

In granting or denying any permit for use of State-owned bot-
tomlands and the waters overlying those lands, the Commis-'
sion considers, among other things, the effect of the proposed
project upon:

1. Other reasonable and permissible uses of State waters
and State-owned bottomlands;

2. Marine and fisheries resources;

3. Tidal wetlands;

4. Adjacent or nearby properties; and

5. Water quality.

The Commission also considers the water-dependency of the
project and any alternatives that are available to reduce any
adverse impacts. The Commission is precluded from issuing
a permit for a marina or other place where boats are moored
without a se@age treatment facilities plan that has been ap-
proved by the State Department of Health.

While local Wetland Boards oftentimes have limited direct
jurisdiction over marina projects, their consideration of the
overall impact of the facility on associated wetland resources

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is important. -Section 28.2-1302(10) of the Code, gives the
16cal Board great latitude to consider a variety of factors
when evaluating a project and making their determination.
TTds may involve an assessment of the potential cumulative
impacts associated with the marina including: pier shading,
shoreline'liardening, dredging, slumping and boat wake in-
duced erosion of adjoining wetland resources, and general
conformity with the standards prescribed in Code. In the
final analysis, approval depends on a majority of the-Board
concluding that the public and private benefits of a marina
outweigh the anticipated detriments expected to result from
the construction, operation, and maintenance of the facility.

Private vs. Community Piers

Section 28.2-1203 provides a statutory exemption for certain
activities within the jurisdiction of the Commission. One
such exemption involves "the placement of private piers for
honcommercial purposes by owners of riparian lands in the
waters opposite those lands, _ provided that the piers do not
extend beyond the navigation line or private pier lines estab-
lished by the.Commission." The Commission requires the
submission of an application on all piers in order that a deter-
mination can be made by Commission staff as to the nature
of the structure and its status with regard to qualifying for
the statutory exemption. In general, staff utilizes the follow-
ing definitions to make a determination regarding pier
status.

A private. pier is generally held to be an appurtenance to
riparian property constructed in the waters opposite said-
property whose use is noncommercial by definition -and de-
signed to provide navigable access and/or mooring for the
riparian owner.

Noncommercial use means a pier which is for individual prop-
erty owner use only, and does not support the sale of goods or

services.

Community piers are generally held to be an appurtenance
to 6. parian property,for which ownership interest in the

Best Management Practices

property is divided between two or more property owners in
the adjoining subdivision or parcel. Community piers are by
definition commercial.

B. Marinas

General Siting Considerations

1. The physical dimensions of the water body should be
compatible with the size of the marina and the type of ves-
sels it is designed to accommodate. For example, a shal-
low cove or basin is not an appropriate site for a deep draft
sailboat marina.

2. Marinas must have sufficient upland area to provide all
necessary parking, stormwater management BMP's, fuel,
and sanitary facilities without filling wetlands or
subaqueous bottom.

3. All marinas should be located in areas with good natural
flushing to minimize the build-up of organic material and
other pollutants on the bottom.

4. Marinas should not be sited close to areas of high natural
resource value such as shellfish beds, SAV and areas
frequented by endangered species.

5. The transfer or control of shellfish leases for the sole pur-
pose of accommodating marinadevelopment is unaccept-
able.

6. Projects that by their cumulative impact will result in
dense concentrations of boats in one area will be critically
evaluated as to their impacts on natural resources; how-
ever, in densely populated areas, concentration of slips in
a single facility may be justified to prevent disturbance of
undeveloped shorelines.

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7. In order to reduce discharges of 'non-point source pollution
into State waters, the Commission will require the appli-
cant to demonstrate how appropriate best management
practices will be incorporated into both the upland develop-
ment plan associated with the facility as well as the Ero-
sion and Sediment Control Plan required by local
government.

8. The Commission may require, as a condition of any permit
issued, that BMP structures be completed before any slips
can be occupied. An appropriate surety bond or letter of
credit may be required to ensure proper installation, stabi-
lization and maintenance of E&S control structures.

Specific Siting Considerations

9: For community piers and marina facilities which are
appurtenances to residential developments, the number
of slips is not predicated on the total number of units on
the property.
10. The dredging of access channels should be limi@ed to the
minimum dimensions necessary for navigation''and should
avoid sensitive areas such as wetlands, shellfish grounds
and submerged aquatic vegetation.

11. Dredge'niaterial disposal areas for initial, as well as,
future maintenance needs should be clearly defined and
designated,

Site specific stormwater management BMP's are required
to minimize runoff of untr'eated sheet flow from buildings
and impervious surfaces.

13. A solid waste disposal and recovery plan must accompany
marina development plans.

14. Sanitary facilities and pumpout facilities convenient to
marina users should accompany development plans.

Best Management Practices

15. Facilities incorporating boat maintenance operations shall
include plans for the collection and removal of mainte-
nance by-products (sand blasting material, paint chips,
etc.) before effluent enters adjoining waterways. Such
plans shall also make provisions for the regular mainte-
nance of these structures.

Recommended Best Management Practices

1. The owner/operator of a marina facility must develop and
implement a fuel spill contingency plan prior to slip occu-
pancy. Th6 plan shall incorporate the following provisions:

a. Gas pumps will be equipped with automatic back
pressure cut-off valves.

b. A deployable containment boom will be stored in an
easily accessible container for rapid deployment.
This boom will be capable of surrounding the fuel
pier and vessels in the immediate vicinity.

c. Floating absorbents and equipment for retrieving the
soaked material.

d. All marina personnel will be instructed in the proper
deployment of the containment boom as well as emer-
gency procedures in the event of a spill.

(1) Confine and concentrate oil with booms.

(2) Remove as much as possible -by mechanical

means.

(3) Absorb and remove remainder with absorbents.

e. Emergency numbers shall be prominently displayed
next to a public telephone at the marina.

Coast Guard (804) 441-3314
State Water Control Board (804) 527-5200

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EPA (215) 597-9898
VMRC (804) 247-2200

.f. In the event of a spill, marina operators are responsi-
ble for contacting the appropriate agencies listed
above and coordinating the recovery with all avail-
able resources including local fire and rescue.

2. Where practical, zonation mooring should be employed to.
limit the amount of dredging necessary and to reduce the
probabi lity of degraded water quality due to poor water
circulation.

3. Travel lift washdown areas shall be equipped with settling
basins to collect particulate matter before the effluent en-
ters adjacent waterways. Provisions shall be made to
clean basins on a regular basis.

4. The use of open-pile piers to gain access are always recom-
mended over the construction of solid fill structures.

5. Where practical, piers constructed- over vegetated wet-
lands should be built at an elevation above the marsh
surface equal to the width of the pier plus 1 foot. Height
above marsh = (width +1). A three foot minimum height
is required.

6. Community Pier permits shall be transferred to the condo-
@minium association if and when one. is formed in conjunc-
tion with the sale or lease of the proposed marina slips.
Note: In the event the permit is transferred to a condomin-
ium association formed to manage common, property, that
association will assume responsibility for all ffiture royal-
ties and conditions of the permit.

Best Management Practices

C. Mooring Buoys

Recommended Best Management Practices

1. Mooring Buoys should not be located:

a. on private shellfish leases or designated imblic shell-
fish grounds.

b. in submerged cable-crossing areas.

c! in or near designated navigational channels.

d. within 200 feet of a public or commercial bathing
beach.

e. so as to interfere with the operation of or access
through any bridge.

f. so as to infringe on the riparian rights of adjacent
property owners.

Maintenance/Reporting

2. Mooring buoys will be marked and maintained in accord-
ance with the "Uniform State Waterway Marking System"
as approved by the U.S. Coast Guard, which requires
buoys to be white with a blue stripe around the middle.

3. Mooring buoys will have their VMRC permit number
affixed to the buoy (e.g. 92-1234). Permit numbers (inini-
mum 1 inch) are to be placed above the water line.

4. Mooring buoys will be removed from State-owned
subaqueous land within ninety (90) days afte r receiving
written notification from the Commissioner or immedi-
ately upon termination of personal use of the mooring
device.

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Best Management Practices

Section IV

Dredging

A. General - Mechanical & Hydraulic

Residential development along Virginia's riverine and
estuarine shorelines continues to spur an ever increasing
-demand for waterfront lots with natural, deep water access.
As the demand for waterfront construction and riparian ac-
cess grows, it is becoming increasingly popular for property
owners living in headwater areas or along shallow coves,
tidal marshes and/or tidal flats, to attempt to modify these
shallow water habitats to better accommodate boating ac-
cess. The result is often a proposal to dredge relatively nar-
row access channels to these properties thereby adversely
impacting a variety of shallow water and intertidal habitats.

One of the many concerns discussed in the review process is
the maintenance of existing vegetated wetland communities
adjacent to proposed channels. The tendency to maximize
dredging effort by going as deep and as wide as possible of-
tentimes has a'devastating effect on adjacent wetlands. As
largely unconsolidated non-vegetated areas slump into
dredge cuts, vegetated wetlands situated too close to the cut
will also slump and forever change the character and compo-
sition of these wetlands. These impacts, however, can be
avoided or at least minimized, through the proper applica-
tion of buffer requirements.

A buffer, in this sense, is generally held to be an undisturbed
area adjacent to a sensitive habitat or structure. The buffer's
purpose is to reduce, or cushion the direct and indirect effects
of dredging by maintaining the integrity of the adjacent
areas. The term "undisturbed" is used here to mean "not cut
with the dredge cutter head. In the past, considerable confu
sion has existed over the exact definition and extent of the
buffer. Due to the nature of a dredging operation it is more
often than not customary for dredge operators to achieve de-
signed side slopes by the box cut method. They simply cut

Shoreline Development

the base width beyond the channel design profile to a point
at which slope failure (slumping) of the vertical box cut pro-
duces a side slope comparable to the design profile. (Fig. 17)
The extent of this encroachment'is necessarily limited to one
half the distance of the design slope. This becomes the land-
ward extent for intrusion with the cutter head. In general,
the buffer starts at the edge of vegetated wetlands and ex-
tends channelward to the landward most swing of the dredge
cutter head. This distance has typically been a minimum of
15 feet where dredge depths are not greater than. 5 feet.

In areas where the width of the waterway far exceeds the
proposed channeldesign width, the maintenance of mini-
mum buffer requirements is generally not restrictive. In
narrower waterways, however, it is necessary. to first con-
sider buffer requirements since these in turn dictate allow-
able channel design widths and depths,.

1. A minimum of 15 feet should be maintained between the
top of the dredge cut, and the. vegetated wetlands. In'those
areas where vbgetated wetlands are not present, a mini-
mum of 15 feet must be maintained between the top of the
dredge cut and the toe of the bank. This landward limit of
encroachment should be flagged and inspecte&prior to
construction.

2. In order to lessen the possibility that dredging will have
adverse effects on commercially or rec rieationally impor-
tant fisheries, certain seasonal dredgipg limitations may

Figure 17. Dredge Cut Section View with Buffer.

4- Buffer

@lurnping

Channel
Design a to be re @e 4 Box Cut
Profile X\V^V&VAVAVA@0,\VAvAVA\vAv@\VAV&N@@\VAV&@M

Best Management Practices

be imposed on a site specific basis. Th@se restrictions will
depend in part on the sediment type, proximity of the pro-
ject to shellfish areas or spawning grounds, dredging
method employed, the proje6t's size, and measur estaken
to reduce turbidity, for instance:

a. No dredging during the period March 1 through May
31. (Anadromous Fish)

b. No dredging during the months of July, August, Sep-
tember, December, January and February. (Oysters)

c. No dredging during the months of December, Janu-
ary, February and March. (Crabs)

3. Individuals wishing to perform- dredging should submit a
dredge material handling plan incorporating the following
components:

a. Plan and section view drawings of the disposal area
including dimensions and material composition of the
proposed berm, and spillway. The disposal area
should be properly prepared to receive and contain
the fill before the start of dredging.

b. A determination of the capacity of the proposed dis-
posal site incorporating the following sizing i-equire-
ments. Generally, hydraulic disposal areas should be
sized to accommodate three (3) times the volume of
material proposed to be dredged. This practice al-
lows for the necessary settling of suspended material
without unduly interrupting the pumping process. A
minimum two (2) foot freeboard for Anal design eleva-
tions within the basin is recommended. Mechanical
dredging operations generally require less storage
capacity due'to the significant decrease in water
volume.

Shoreline Development

c. Detailed pipeline support and maintenance informa-
tion needs to be supplied with hydraulic operations
proposing to pump over adjacent wetland areas.
Such information should include the method of pipe-
Jine deployment, location of booster pumps (if nece Is-
sary), and a plan for restoring impacted areas to
preconstruction contours. and conditions..

d. Mechanism employed to de-water dredged material.
Pipeline outfalls. and spillways should bellocated at
opposite ends of the containment area to allow for
maximum retention and settling time. Weirs and/or
baffles may be utilized to aide settling. Spillboxes,
spillways, and risers should be constructed of metal.
Wooden outfall. structures are generally not suitable.

e. Clamshell and/or dragline operations need to identify
the loading/olb@-Ioading points for transporting dredge
material. Precautions need to be established to pre-
vent further despoliation to surrounding, wetlands
and subaqueous bottom.

4. All dredging will be done so as to minimize bottom distur-
bances or turbidity increases which tend to degrad e* water
quality and damage aquatic life.

5. The deposition of dredged material on shore and all earth-
work operations on shore will be carried out in such a way
as to minimize erosion of the material and prevent its
reentry into adjacent wetlands, or waters of the Common-
wealth.

-6. Any vegetated wetland disturbed during construction will
be restored to preconstruction contours and conditions.

7. Dredge depths are dictated by the proposed use of the
waterway and controlling water depths outside the area to
be dredged. Where possible, zonation dredging should be
utilized to minimize the amount of dredged material.

Best Management Practices

8. Over-dredging to reduce the frequency of maintenance
dredging should not exceed an additional I foot and the
need for over-dredging should be based on the expected
rate of sedimentation at the dredge site. If authorized,
over-dredge allowanceswill be explicitly stated in permit
documents and should not to be assumed.

9. Dredging for proposed small craft channels should be no
more than one foot deeper than 'adjacent natural water
bodie!@ and only as wide as necessary to avoid creating
circulation and flushing problems. Dredging to depths
deeper than the nearest channel can create stagnant 'condi-
tions which can lead to decreased oxygen levels, unpleas-
ant odors and the death of local marine resources.

10. The dredging of shellfish areas, beds of submerged aquatic
vegetation and other highly productive areas is generally
prohibited.

11. Overboard disposal of dredgod material into tidal waters
is generally not permitted.

a. When overboard disposal is authorized, areas to be
used for placement of the material will be located to
minimize impacts on commercially important bottom
dwelling organisms such as oysters and clams, sub-
merged aquatic vegetation, wetlands and other pro-
ductive shallow water habitats.

b. Overboard disposal areas should be properly shaped
and positioned to reduce scour and. sedimentation.

12. Quality dredge material may be used for beach replenish-
ment at various public beaches in Virginia where natural
sources of sand supply are inadequate. See "Criteria for
the Placement of Sandy Dredge'Material Along Beaches in
the Commonwealth."

Shoreline Development

13. Sand Mining See Sand Mining Regulations for Addi-
tional Information

B. Beach Nourishment

1. Jn accordance With the Criteria for the Placement of Sandy
Dredged Material along Beaches of the Commonwealth,
the following general criteria should be used to determine
candidate projects suitable for detailed evaluation:

a. Dredge projects with a total volume greater than
7,500 cubic yards and with a reasonable expectation
that suitable beach nourishment material is present
in the dredge material;

b. Beaches are located within proximity of the dredge
site with a demonstrated need and capacity for ac-
cepting all or part of the available material;

c. The political subdivision within which the potential
placement site is locate& has expressed an interest in
obtaining nourishment material;

d. Applicants will be required to undertake the research
necessary to locate private property owners willing to
accept the material if no publicly owned shoreline is
.in reasonable proximity;.

e. When beach nourishment is incorporate d into a
dredging project, a comprehensive subsurface investi-
gation plan is required including sufficient borings to
determine the limits of sand deposits.

2. Every reasonable effort will be made to minimize destruc-
tion of submerged aquatic vegetation in the proximity to
the beach nourishment sites authorized for placement of
suitable material.

Best Management Practices

Section V

Instream Work

General

In addition to having regulatory authority over activities within
tidal waters and along the shorelines within the Common-
wealth, the Marine Resources Commission also has jurisdiction
over the beds of all non-tidal, perennial'rivers, creeks and
streams throughout Virginia. In many western areas this is not
widely known, but through contact with other Sta te agencies,
such as the Department of Environmental Quality, the Depart-
ment of Conservation and Recreation, and the Department of
Game and Inland Fisheries, the regulated public is becoming
more informed of the Commission's responsibility over activities
in these waterways.

Pipeline, powerline, bridge, and aerial crossings, stream chan-
nelization, and dams for creating stormwater management' im-
poundments are examples of the types of activities which the
Commission regularly reviews in cooperation with other State
and Federal agencies prior to permit issuance. The excavation
or mining of sand from jurisdictional river and stream beds also
comes under VMRC review and specific regulations are cur-
rently being promulgated to address the environmental issues
related to these activities.

The main goals in reviewing projects involving instream work
are to prevent the loss or deterioration of aquatic habitat, mini-
mize water quality impacts, maintain or improve ambient flow
rates, and preserve the natural contours and conditions -of the
stream bed and adjoining stream bankg to the greatest extent
possible. Advice and guidance on appropriate construction tech-
niques which achieve these goals are offered through the Depart-
ment of Conservation and Recreation's Division of Soil and
Water Conservation as well as the Department of Environ-
mental Quality and the Department of Game and Inland Fisher-
ies. The Commission also works closely with the field offices of
these agencies, which in most cases are geographically closer to

Shoreline Development

western sites and generally contain first-hand information of
site-specific concerns regarding proposed work within a particu-
lar waterway. The Best Management Practices listed below will
give the applicant an idea of some general conditions which may
be imposed on a permitteeto ensure- compliance with stated
goals.

Recommended Best Management Practices

1. All interests of the Commonwealth over the original
streambed shall be transferred to the new streambed upon
completion of a channelization project.

2. Prior to diverting an existing water course into a new
channel, all proposed channelization work, including slope
stabilization, shall be completed.

3. New channel construction should recreate the pre-existing
stream conditions including strearobed widths, streambed
depths, stream meanders, pools and riffles, and existing
streambed cover in the new channel. This includes the
construction of a low-flow channel within the confines of
the new channel whereby low normal flows shall be more
confined than flood stream flow.

4. Instream construction activities shall be accomplished
within cofferdams constructed of non-erodible materials in
such a manner that no more than half the width of the
waterway shall be obstructed at any point in time in order
to minimize instream habitat disturbances and water
quality degradation.

5. Cofferdams and any excess material will be removed to
approved upland areas upon completion of construction,
and the streambed and banks shall be restored to pre-ex-
isting contours and conditions.

Best Management Practices

6. To the greatest extent possible, construction shalf be per-
formed during low-flow conditions and during the period
June 1 through September 30.

7. Virginia's Best Management Practices for silt and erosion
control will be followed throughout construction for stabili-
zation ofadjacent upland.

8. If blasting is necessary, the Marine Resources Commission
shall be notified a week prior to the blasting to permit
agency representatives to observe the operation.

9. All areas of State-owned bottom and adjacent lands dis-
turbed by instream work shall be restored to their original
contours and natural conditions within ten (10) days from
the date of coinpletion of instream work. All excess mate-
rial shall be removed to an upland site and contained in
such a manner as to prevent it's reentry into State waters.

10. Where practical, new overhead crossings should be located
at or near existing crossings.

11. Where practical, overhead structures should be designed
in such a manner that instream activity is minimized or
eliminated.

12. Directional drilling is a preferred alternative to trenching
and backfilling. Where directional drilling is deemed to be
a possible alternative but is not being utilized, sufficient
documentation will need to be provided to explain why di-
rectional drilling is not being employed.

13. The pouring of wet concrete within State waters is discour-
aged because of the documented adverse impact on
aquatic resources.

14. In order to lessen the possibility of dredging having ad-
verse effects on commercially or recreationally important
fisheries, certain seasonal dredging limitations may be

Shoreline Development

imposed on a site specific basis. These restriction will de-
pend in part on the sediment type, proximity of the project
to shellfish areas or spawning grounds, dredging method
employed, the project's size, and measures taken to reduce
turbidity.

a. No dredging during the period March through May
31. (Anadromous Fish)

Best Management Practices

Section VI

Glossary

BEACH - The shoreline zone comprised of unconsolidated sandy
material upon which there is a mutual interaction of the
forces of erosion, sediment transport and deposition that
extends from the low water line landward to where there is
a marked change in either material composition or physiog-
raphic form such as a dune, bluff, or marsh, or where no
such change can be identified, to the line of woody vegeta-
tion, or the nearest impermeable manmade structure.

BMP - Best Management Practice. In general, BMP's ate meas-
ures that have the combined effect of helping to ensure
project integrity for the design life of the project while mini-
mizing the potential adverse impacts associated with con-
struction and maintenance.

BOX CUT - The physical profile of a dredge cut. Typically,
areasF are box cut with a hydraulic cutter head or mechani-
cal clam shell and adjoining undisturbed sediments will
slump into the box cut area in an attempt to reach a more
stable slope. Generally, the finer the gain size of the sedi-
ments, the flatter the slope.

BULKHEAD - A vertical structure or partition, usually running
parallel to the shoreline, for the purpose of retaining up-
land soils while providing protection from wave action.

CHANNEL DESIGN PROFILE - The proposed section view of a
dredged area after slumping. Usually including side slopes
of 2:1 or 3:1.

COASTAL PRIMARY SAND DUNE - A mound of unconsoli-
dated sandy soil which is contiguous to mean high water,
Whose landward and lateral limits are marked by a change
in grade from ten percent or greater to less than ten per-
cent and upon which is growing as of July one, nineteen

Shoreline Development

hundred eighty, or grows thereon subsequent thereto, any
one or more of the following plant species: American beach
grass; beach heather; dune bean; dusty miller;,saltmeadow
hay; seabeach'sandw'ort; sea oats; sea, rocket; seaside gold-
enrod; and short dune grass. The following localities are
currently authorized to adopt the coastal primary sand
dune ordinance: the counties of Accomack, Lancaster,
Mathews, Northampton, and Northumberland, and the
Cities of Hampton, Norfolk, and Virginia Beach.

COMMISSION - Virginia Marine Resources Commission: A nine
member citi zen board appointed by the governor and
chaired by a Commissioner who serves a dual role as
agency head.

DREDGE BUFFER - An undisturbed area adjacent to a sensi-
tive habitat or structure. Generally,'the buffer starts at
the edge of a vegetated wetland and extends channelward
to the landward most swing of the dredge cutter head.
This distance has typically been a minimum of 15 feet. The
term "undisturbeT is used here to mean 'not cut with the
dredge cutter head."

DREDGED MATERIAL - The material removed from a channel
bottom or other water body during a dredging operation.

FRESH WATER - Water containing no appreciable@ salt, usually
less than 0.5 parts per thousand.

GABION - A container filled with stone, brick or other material
to give it a weigtit suitable for use in revetments or break-
waters. in the marine environment, usually r@ade of galva-,
nized steel wire mesh with a PVC coating.

GROIN - A shore protection structure'built pe rpendicular to
shore to trap sand moving along the shoreline in order to
accrete sand and thus retard erosion of-the shore.

JETTY - A structure extending into a body of water designed to
prevent shoaling of a channel.

Best Management Practices

KNEE BRACING - Piles secured to the bulkhead extending
channelward from the face to provide increased stability in
situations where the proper application of deadmen is not
possible.

LITTORAL PROCE SS - Those physical features and charac-
teristics of the, intertidal area which determine the type of
shoreline present.

LOW PROFILE GROIN - Low profile groins are structures with
a terminal elevation at mean low water extending land-
ward to an elevation of 1 foot above-mean high water, with
the landward terminus extending into upland to reduce
flanking.

MEAN HIGH WATER (MHW) - The average height of high
waters over a ninetee* year period.

MEAN LOW WATER (MLW) - The average height of low waters
over a nineteen year period.

MEAN TIDE RANGE - The vertical distance between mean
high water and mean low water.

OVERBOARD DISPOSAL - The practice of placing dredged
material on subaqueous bottom in lieu of upland disp osal.

PIERS -
A PRIVATE PIER is generally held to be an appurtenance
to riparian property constructed in the waters oppo-
site said property whose use is noncommercial by
definition and designed to provide navigable access
and/or mooring for the riparian owner.
NONCOMMERCIAL use means a pier which is for individ-
ual property owner use only, and does not support the
sale of goods or services.
COMMUNITY PIERS are generally held to be an appurte-
nance to riparian property for which ownership inter-
est in the property is divided between two or more
property owners in the adjoining subdivision or par-
cel. Community piers are by definition commercial.

Shoreline Development

PRESSURE TREATED - The process whereby wood in impreg-
nated with certain chemicals to reduce or retard invasion
by wood destroying organisms.

REACH - A discrete portion of a river, stream or creek some-
what homogeneous in its physical characteristics and upon
which there is mutual interaction of the forces of erosion,
sediment transport, land accretion.

RIPRAP - Stone that is hard and angular and of such a quality
that it will not disintegrate on exposure to water or weath-
ering and it shall be suitable in all other respects for the
purpose intended. No individual armor unit should be
longer than three times its minimum dimension.

SEDIMENT BARRIERS - Structures placed at the toe of a slope
or in a drainageway to intercept and detain sediment and
decrease flow velocities from drainage areas of limited size,
Barriers may be constructed using posts and filter fabric
properly anchored at the base and/or straw 'bales staked in
place end to end or any combination of the two.

SHEET PILE -',Typically, a wooden plank or steel sheet used in
the construction of bulkheads and groins.

SLOPE - Degree of devi@tion of a surface from the,horizontal;
measured as a numeric ratio, percent, or in degrees. Ex-
pressed as a ratio, the first number is the horizontal dis-
tance (run) and the second is the vertical distance (rise), as
2: 1. A 2: 1 slope is a 50 percent slope. (Slope is actually de-
fined as rise/run (1:2 or 1:3), but is generally referred to as
run/rise.)

SUBMERGED LANDS - Those ungranted lands beneath the
tidal waters of the Commonwealth extending -seaward from
the mean low water mark to the 3 mile limit (Territorial
Sea) and including nontidal freshwater subaqueous bottom-
lands; or lands beneath freshwaters extending channel- f
ward from the ordinary high water mark. The upper limit
of VMRC jurisdiction, at the present time, is considered to.

Best Management Practices

be where waterways reach a minimum average annual
flow rate of five (5) cubic feet per second.

TIME OF YEAR RESTRICTIONS - Restrictions which limit
bottom disturbing activity during periods of heightened
sensitivity for certain aquatic organisms.

WALER - A wooden plank used in bulkhead construction to help
support sheet piles.
I
WEEP HOLES - Holes placed in the face of a bulkhead at regu-
lar intervals to allow water to seep from behind the struc-
ture and reduce excessive back pressure caused by the
weight of the water.
WETLANDS - Tidal wetlands, as defined in Section 28.2-1300 of
the Code of Virginia, means both vegetated and nonvege-
tated wetlands. -
VEGETATED WETLANDS - Lands lying between and con-
tiguous to mean low water and an elevation above
mean low water equal to one and one-half times the
mean tide range at the site of the proposed pro-
j ect ....... upon which is growing any one of the 37
plant species identified in Code.
NONVEGETATED WETLANDS - Unvegetated land lying
contiguous to mean low water, and between mean low
water and mean high water, including those'unvege-
tated areas of Back Bay and the North Landing River
subject to flooding by normal and wind tides.

FEDERAL DEFINITION: Areas that are -inundated or
saturated by surface or ground water at a frequency
and duration, sufficient to support, and that under
normal circumstances do support, a prevalence of
vegetation typically adapted for life in saturated soil
conditions.
WETLANDS BOARD - A board created pursuant to Section 28.2-
1303.

ZONATION - The practice of terracing depth requirements such
that shallow draft vessels are moored closer to shore while
deeper draft vessels are located progressively more chan-
nelward.

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