Installing living shorelines with biogenic reefs as sills dramatically reduces destructive shoreline erosion
List specific activities or specifically what your solution does.
ReadyReef makes and installs appropriately sized biogenic reefs along the shoreline. Reef size is matched against the wave energy potential of the site.
ReadyReef can be pre-seed the reefs with live animals, or the reef's construction design specifically attracts settlement of native spawning oyster larvae in the install location.
The reefs themselves are designed to hydrodynamically reduce wave energy by disrupting the wave and/or causing it to break. Additionally, as oysters populate the reefs, they will absorb wave energy between their shells and grow out laterally and vertically to increase the size of the reef. As sea level rises the oyster will grow upwards with it. The structures also create quiet deposition zones that accumulate sediments, especially those eroding from up slope areas. This prevents loss of soil to the sea. The regrading, combined with the reef protection, often encourages natural marshgrass expansion.
These activities have been piloted at numerous other sites.
ReadyReef, on this project, will also complete the living shoreline behind the sill by backfilling with material that will support newly planted marshgrass plugs. This expands the wave disapation capability of the system, as well as allows for more expansive root grown into the soil.
ReadyReef has partnered with suppliers who can deliver adjacent dredged material in lieu of long haul, imported materials like clean sand. The locally sourced materials have high organic content, which clean sand takes 5 years or more to develop. The shoreline remains vulnerable until the roots secure it. Frequently, the imported sand is dredged material itself anyway.
ReadyReef's partners/subcontractors are developing systems on this project to completely contain the dredged material, which has frequently had very negative connotations.
Dredged material potentially has, besides its compatibilty with the environment, the side benefit of removing material that has silted in the landowner's dock and increasing access to deep water. Here is a value proposition that will help motivate shoreline property owners to take action to create a natural, living shoreline.
ReadyReef and its partners (including the VA Master Gardeners program) is developing a solution on this project for securing steep and high embankments which have sterile, exposed soils resistant to being covered and protected by root systems. These steep slopes are very vulnerable to storm surge.
The actual phases of the project are:
Zone 1: This area is being pummeled by NW to NE waves that are refracting around the rip rap headland and eating away of the cliff immediately behind it. It has actually uncovered an old dump site about 15' up on the steep slope that is raining old bottles and debris onto the beach below. If not arrested, erosion of this wall will eventually undermine the house foundation on the property.
Create a base of material out at the project material to support a double row of 2' reefs such that their tips are at MHW. See attached drawing. Backfill the area with dredged material from the customer's shallow dock area. The material will be built up to where the Filtrexx Trinity Living Wall structure begins. The Living Wall will become the new escarpment face. Marshgrass plantings at the correct elevations will be done in the backfill. Master Gardener specified plants will be planted or have seed embedded in the Living Wall, and supported by an irrigation system in the layers.
Zone 2: This area is directly to the South of Zone 1. It is more subject to SW and boat wake than the northern section.
A double row of 1' structures will be placed at the MLW line. This design will encourage a natural regrading behind the reefs that will not involve backfill. There is some marshgrass in the area that will be protected by the reefs and is expected to encourage a natural reseeding of the area.
Zone 3: This is in an area where there is no erosion, but it will be installed as an off-shore break zone.
A double row of pre-seeded reefs will be put into water such that the tips are at MLW. The reefs will cross under the dock for easy observation as to their growth and effect on inbound waves. It will be several years before the reef grows to a mature size with first generation oysters. However, they will be studied to see how the reef grows, both laterally and vertically.
Zone 4: This area, unlike Zones 1-3 on the west face of the peninsula pointing north, is on the east side. Heavy NE winds send waves in from deeper water that are eroding a marsh and, in storm surge mode, attacking the steep embankment.
A double row of 2' structures will be established perpendicular to the NE attack. Behind this first 50' of reef, another living shoreline will be installed in the cove area there. The steep slope here might be turned into a terraced Living Wall, Design work is ongoing. Out at the 50' mark, the rows will turn to South, adjacent and parallel the marsh toe, which is an eroding base. The reefs in this case will preserve the marsh, which in turn is protecting the high ground on the peninsula.
The client is Oyster Company of VA, who is committed to this project to showcase near shore oyster reef contributions. OCVA does not view ReadyReef as a competitor, but as a complimentary line of products to their off-shore products, used primarily for oyster aquaculture. OCVA brings in large number of student groups for environmental studies and has a first rate facility on the hill that is the peninsula. They are committed to on-going access to the project by those interested in the demonstration project.