Sediment Management in the

Coastal Bays

• Introduction – Need for ecosystem view of sediment management in Coastal

Bays • Island loss and restoration

• Navigation needs

• Habitat Trade offs

• Living Shoreline Requirements

• Background – Barrier Island dynamics

• Goals – Discussion

• Sediment Management Plan

• Navigation Committee Resurrection?

• Permit Streamlining?

Completed

1. Restoration of northern end of Assateague Island

2. Restore a total of 5 ha (12 ac) of salt marsh at the

Isle of Wight Wildlife Management Area and

3. Restore a total of 3.4 ha (8.5 ac) of salt marsh at

Ocean Pines,

Ocean City Feasibility Study 1998

Sand management plan to implement navigation

improvements and restore fish and wildlife

habitat

Ocean City Feasibility Study 1998

• To Be Done

• 4. Stabilize the eroding South Point Island to its 1997 size of approximately 0.93 ha (2.3 ac),

• 5. Construct a new 1.2 ha (3 ac) island in proximity to South Point to create vegetated habitat for colonial waterbirds, and

• 6. Create a 1.2 ha (3 ac) island near Dog Island that will be bare substrate with a shell surface for colonial waterbird nesting. The island created near Dog Island will also include three additional cells that will be available to local citizens, businesses, and government for the placement of material dredged locally. Thus, an additional 1.2 ha (3 ac) area of salt marsh will be added in the near future, and up to 8 ha (19 ac) area could eventually be created, increasing the size of this island to as much as 10 ha (25 ac).

Navigation and Dredging Advisory Group (NADAG) for

Maryland’s Coastal Bays (met initially Dec 1999, stopped meeting ~ 2003)

Navigation and Dredging

Planning Guide

for Maryland’s Coastal

Bays

edited by Cornelia Pasche

Wikar

Chair, Navigation and

Dredging Advisory Group

August, 2005

Recommendation:

A.i.i. Support for and promotion of the beneficial

use of dredged materials, including

- habitat restoration and creation.

- restoration of underwater grasses;

- restoration of islands;

- stabilization of eroding shorelines;

- creation or restoration of wetlands; and

- creation, restoration, or enhancement of

fish or shellfish habitats

• Beneficial Uses Introduction Decision Process Sediment Types Glossary Links References K-12 Lessons Lead Organizations Authorities Calendars

• Agricultural/Product Uses Aquaculture Construction Materials Decorative Landscaping Products Topsoil

• Engineered Uses Beach Nourishment Berm Creation Capping Land Creation Land Improvement Replacement Fill Shore Protection

• Environmental Enhancement Fish & Wildlife Habitats Fisheries Improvement Wetland Restoration

Beneficial Use of Dredge Material

http://el.erdc.usace.army.mil/dots/budm/budm.cfm

Maryland Case Studies

Barren Island, MD

Bodkin Island, MD

Eastern Neck National Wildlife

Refuge, MD

Hart-Miller Island CDF, MD

Kenilworth, MD

Slaughter Creek, MD

Twitch Cover Seagrass Plantings

Dead end canals

North end of Assateague

Inlet, commercial harbor,

Assawoman channel

Sediment Sources

Source: COE 1998

Uses for sediments

Isle of Wight marsh restoration using

dredge material from the Assawoman

channel

View from pier looking south

Stone sill

Uses for sediments

Marsh protection and enhancement

behind low profile stone sills

along high energy shorelines

Assawoman Bay

Sunset Island

Carlson (Thoroughfare)

Marsh creation in low energy shorelines

Herring Crk

Source: Shifting Sands 2009 Chap 12

Barrier Island Formation

Barrier Island Dynamics

Source: Shifting Sands 2009 Chap 12

Source: Shifting Sands, 2009 Chap 12

Islands: Overlooked

Coastal Landforms

Island Formation:

Mainland: high topographies

and the degree to which

sedimentation is able

to offset submergence

Back barrier islands

washover fans, storm-surge

platforms, old beach ridges,

portions of flood deltas

.

Source: Shifting Sands, 2009 Chap 12

Source: Shifting Sands, 2009 Chap 12

Former flood

tidal delta

Source: Shifting Sands, 2009 Chap 12

Source: Shifting Sands, 2009 Chap 12

Sediment Distribution Based on Island Dynamics

Source: Shifting Sands, 2009 Chap 12

Sea Level Rise

Potential mid-Atlantic coastal

landform responses to three sea-

level rise scenarios. Most

coastal areas are currently

experiencing erosion, which is

expected to increase with future

sea-level rise.

In addition to undergoing erosion,

coastal segments denoted with a

“T” may also cross a threshold

where rapid barrier island

migration or segmentation will

occur.

U.S. Climate Change Science Prog Synthesis and Assessment

Product 4.1, Coastal Sensitivity to Sea Level Rise:

A Focus on the Mid-Atlantic Region, 2009

Source: Sea Level Rise Response Strategy

Worcester County, Maryland

September 2008

Source: Sea Level

Rise Response

Strategy,

Wor Co, MD 2008

Goals

1. Review and update extent of dredging needs

2. Identify/and Explore capabilities and

opportunities for dredged material

management

3. Engage user-groups and community in

developing the Sediment Management Plan

4. Develop a Sediment Management Plan for the

Coastal Bays

5. Establish a Committee to oversee, match and

traffic sediments

Goals Con’t

• The commission would navigate between 1) projects that generate sediments, such as navigation dredging projects; and 2) projects that require sediments such as various restoration projects (e.g. Skimmer Island other wetland restorations).

• Permitting should be streamlined. Specific projects such as the Skimmer Island restoration or Dog Island site would be set up, ready to accept sediments; with permitting requirements in place. That way, when a dredging job, either private or public, comes along, everything would be ready to go. The only thing needed is an assessment of the type of sediment being dredged, analyses including textural and chemistry.

• If the sediment is sand, then it’s good for island restoration or beach replenishment; if it’s fine-grained, then it’s good for wetland creation or maybe island restoration.

Sediment Management Plans

• San Francisco Bay area

• Columbia River, Oregon

• Great Lakes,

• Jamaica Bay , Long Island, NY