By: Gwynn Crichton
Storms like Hurricane Sandy blow into town and take expensive coastal real estate when they leave. Such was the case for many East Coast properties, including Occohannock on the Bay Camp and Retreat Center, a 50-year-old Methodist summer camp in Belle Haven, Virginia.
The camp is set at the mouth of Occohannock Creek, the largest tidal creek along Virginia’s Eastern Shore that flows placidly into the Chesapeake Bay. In the wake of Sandy, this peaceful and picturesque area lost two feet of valuable shoreline—a shoreline that had already been receding at a rate of a foot a year. Battering by storms over the years, combined with steadily rising sea levels, left a stark 12-foot vertical mud embankment instead of the gently sloping, extensive tidal marsh that had historically been in its place.
Traditional Approaches, Unintended Consequences
This is a typical predicament that landowners along Chesapeake Bay tributaries in Virginia and Maryland face. They must grapple with the one-two punch of the increasing number of extreme storms associated with global climate change, as well as with sea-level rise along the Mid-Atlantic coast, which is accelerating at three to four times the global average.
Well-intentioned landowners and land managers tend to respond to erosion by armoring the shoreline with hardened structures, such as bulkheads, revetment, and concrete seawalls. These structures often have the unintended consequence of increasing the rate of coastal erosion on neighboring properties and preventing the shoreline from carrying out important natural processes. Erosion can lead to a loss of valuable infrastructure for people, such as roads and houses, as well as the loss of habitat for coastal birds, waterfowl, finfish, shellfish, and crab, all of which are culturally and economically important natural resources in coastal communities.
Maintaining Critical Connections
In October 2013, The Nature Conservancy (TNC) and the Eastern Shore Resource Conservation & Development Council (RC&D) finished a project that took a novel approach to preventing erosion caused by storms and flooding. With help from more than a dozen volunteers, TNC and RC&D planted 4,000 plugs of marsh grass (Spartina patens) along a newly graded and constructed “living shoreline,” which will protect the camp’s 1,000-foot shore.
Living shorelines use plants, sand, and limited rock to ensure that the critical connection between the land and sea is maintained so that natural coastal processes can function and wildlife can thrive. Living shorelines also harness the functions associated with habitats like salt marshes to buffer strong waves, in combination with a properly designed and placed low rock wall (or “sill”) or oyster reef in front of the marsh.
The completed shoreline project at the camp is designed to withstand a major storm event that has a probability of occurring once every 25 years, producing a storm surge of up to 5 feet above the average water levels.
To achieve this level of protection at the camp, 700 metric tons of granite rocks were trucked in to build four 2-½-to-3-½-foot rock sills parallel to the shore, each varying in length between 100 and 220 feet. In addition, more than 700 cubic feet of sand were added to the shoreline to create a new salt marsh terrace behind the rock sills.
The cost of the project was $160 per linear foot which is equivalent to the cost per linear foot of traditional armoring approaches, such as a riprap revetment wall placed on the shoreline itself. There are many examples of revetments upstream of the camp and in each case, the marsh has disappeared, diminishing its valuable role for people and nature.
Demonstrating Natural Defenses
Because of its high visibility from the water and the steady traffic of children and families that spend time at the camp throughout the year, Camp Occohannock is an ideal site for demonstrating living shoreline approaches to the surrounding community.
Both RC&D and the Virginia Institute of Marine Science (VIMS) identified Camp Occohannock as a candidate for a living shoreline during their shoreline planning process in 2006, but no money was available at the time to do the project. Since then, TNC partnered with the camp, RC&D, and VIMS to secure the funding necessary for implementation.
TNC aims to work with partners in this way to demonstrate that approaches like living shorelines that incorporate natural defenses should be considered part of a smart portfolio of solutions that help protect people and nature from climate hazards such as storms and coastal flooding.
As part of the Camp Occohannock living shoreline demonstration project, TNC and RC&D will host a series of community outreach and education workshops for local landowners, which will explore the benefits, permitting procedures, and costs associated with living shorelines compared to conventional methods.
With its new living shoreline, the camp will benefit from the blending of engineered and natural solutions in adapting to sea level rise. The resulting project should both effectively protect property and infrastructure from coastal storms and erosion, while also ensuring that a healthy and productive coastal ecosystem remains resilient over time.
Young campers will be able to explore the wonders of a salt marsh for the first time, picking up their first ribbed mussel or blue crab, gawking at a great blue heron as it takes flight after an early morning of fishing, and trying to catch schools of minnows darting in and around the rock sills that are covered with oysters. This is the first at-scale living shoreline project to be completed in Accomack County and only the second on the Eastern Shore of Virginia.
Bay Journal: Project Helping a Living Shoreline to Emerge on Shore VA Creek (February 6, 2014)
Richmond Times-Dispatch: ‘Living shoreline’ meant to undo Sandy’s damage (November 2, 2013)