U.S. Navy Photos by Doug Davant Officials from the USDA NRCS survey erosion at Indian Head Pilot Plant. Included (from left) are: Allan Stahl (wearing blue jacket), a USDA NRCS state conservationist engineer; Jeremy West, (sunglasses) a coordinator from Southern Maryland Resource Conservation and Development; Jon Hall (black jacket), USDA NRCS Maryland State Conservationist; Seth Berry of NSASP; Terry Heinard (grey sweat shirt), USDA NRCS District Conservationist; Olga Walter, Treasurer⁄Secretary, Southern Maryland Resource Conservation and Development; Mark Rose, USDA NRCS Assistant State Conservationist for Programs and Glenn Gass, Charles County Soil Conservation District Engineer.

‘‘They came down because of a cooperative agreement between the Navy and Southern Maryland’s Resource Conservation and Development Board,” said Seth Berry of the Naval Support Activity South Potomac’s environmental office.

Berry explained that the 17 miles of shoreline of NSF Indian Head is losing beach at the erosion rate of 1.5 feet per year to the Potomac River, Mattawoman and Chicamuxen Creeks because of wave action, storms, human activity, ground water seepage and the geology of the soil indigenous to southern Maryland. The shoreline restoration program that Navy began at NSF Indian Head last autumn holds the promise of checking that erosion.

A series of breakwaters and sills along the eastern shore of the Potomac River is currently being constructed and will protect Indian Head’s shoreline while providing a habitat for aquatic wildlife. Berry said that the first phase of the restoration project provides breakwaters and sills will extend about 3,600 feet along the shoreline and that stabilization will greatly reduce or eliminate impacts of the wave action of the river. As a result, he said, nearly 2,100 feet of shore line will naturally stabilize and an area of approximately 11 acres will fill in behind the project with a vegetated wetland habitat.

The shoreline of the greater Chesapeake Bay is threatened the entire length of its tributary rivers and creeks according to conservationists. There are two types of erosion in the Bay region, say conservation officials at the Chesapeake Bay Program (Maryland and Virginia watershed partnership): upland erosion and tidal erosion. Erosion is a natural occurrence influenced by climate and geology, as well as non-sustainable land use and other human activities.

Upland Erosion Increases Sediment

In the Bay, conservationists say, upland erosions have meant that river basins with the highest percentage of agricultural lands yield the highest overall amount of sediment each year, while basins with the highest percentage of forest cover yield the lowest amount of sediment. However, on a per-acre basis, construction sites can contribute the most sediment of all land uses—as much as 10 to 20 times that of agricultural lands. Urbanized areas can contribute high amounts of sediment because of their use of impervious surfaces—roads, parking lots and other hardened surfaces that do not allow water to pass through. The increased water flow off these surfaces can cause extensive stream channel erosion.

Since the 17th century, land use and land cover changes in the Bay watershed have severely disrupted natural erosion processes. During the 18th and 19th centuries, 70 to 80 percent of the watershed's original forest cover was cleared for timber and agriculture. Cleared, exposed land is especially prone to erosion. Deforestation peaked in the late 19th century, and reforestation took place during the 20th century. However, increased urbanization contributed to continued high erosion rates during this time. Studies of sediment cores in the Bay and its tributaries show a four-to five-fold increase in sediment accumulation in some parts of the Bay since the 1800s.

Impact of ShorelineDevelopment

Also, the Bay's shorelines have been slowly eroding for thousands of years due to wave action and natural sea level rise. However, some tidal erosion can help maintain the Bay's complex ecosystem. Beaches and tidal wetlands, which are created and replenished by erosion, provide habitat for blue crabs, herons, terrapins and many other species. But shoreline development has several negative impacts on natural tidal erosion, say conservationists.

Homes built along the shoreline often result in hardened shorelines – those lined with rocks, wood or concrete (not breakwaters or sills) – can interfere with natural tidal erosion processes by blocking the formation of wetlands and starving beaches of new sediment. They also eliminate natural shorelines, which provide habitat for many plants and animals. Wave action causes the bottom of the shallow water area immediately in front of the hardened shoreline to erode. This is called near shore erosion, and it increases suspended sediment that blocks sunlight from reaching underwater bay grasses. Between 1988 and 2000, an average of over 19 miles of Virginia tidal shoreline was hardened each year. In Maryland, more than 300 miles of tidal shoreline were hardened between 1978 and 1997.

In 2002 NSF Indian Head began to look at new ways to manage shore line erosion, while protecting infrastructure critical to the Navy mission there and at the same time improve water quality and wildlife habitat. A Shoreline Management Plan, based on a survey done to assess erosion, was completed along 17 miles of base shoreline. Hurricane Isabel, however, struck the installation in 2003 and, as a result, the Navy received approximately $5.3 million to repair damages done by the storm. The funds were used to prepare a development plan and begin construction of the first phase of the shoreline stabilization project.

Extended Project Protects Indian Head<P> This first phase is now under way and was expected to take a year to a year and a half to complete when it began this past November. Additional phases of the construction are planned, with another phase (additional $5 million received this fiscal year) planned following the agreement with the Southern Maryland Resource Conservation and Development Board signed this year. The follow on phase is planned for December and will stabilize another 3,500 of river shoreline.

Additional follow-on phase planning and design for the entire NSF Indian Head shoreline area are also under way, with funding anticipated ($5 million) for fiscal year 2009 and 2010.