An Overview Of Our Solution
At the Client site in Topping, VA, ReadyReef is implementing a comprehensive solution to agressive marine erosion.
Historically, the Chesapeake Bay owes its origin to flooding of the Susquehanna River Valley as sea level rose following the ending Pleistocene Ice Age. English explorers found extensive oyster reefs lining the shoreline, filtering the water, breaking wave energy and protecting the marshgrass. The grasses protected the water from runoff. The result was clear, healthy water.
The rising water process has continued, but shoreline protection by reef and marsh stopped due to harvest of all oyster "rock".
The solution is to reestablish the vertical oyster habitat and marshgrass at the estuarine shoreline.
ReadyReef has successfully demonstrated in pilot projects how the reefs can serve as a living, growing sill for Living Shoreline projects.
Additionally, ReadyReef will implement solutions for providing highly organic backfill for the marsh planting area and a marine compatible solution for an eroding high escarpment using a living wall of densely packed, anchored live plantings.
Living reefs and extensive soil root structure minimizes erosion problems.
- Population Impacted: All marine users and adjacent property owners
- Continent: North America
Address
504 Smoketree Ct
Richmond, VA 23236
États-Unis
Hazard
Identify the likelihood and frequency of this hazard
Explain how vulnerable the community is to this hazard
List the potential affects of this hazard
Identify how sensitive the community is to these affects
Preparedness Goal
Implementation Actions
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.
Describe Your Solution
Describe your solution. How do these combined actions reduce risk from weather-related disaster impacts?
The biogenic reefs perform by breaking wave energy that can normally pound soil loose from the shoreline behind it.
The reefs afford enough protection to the marshgrass roots that they prosper behind the reefs and actually expand. Without the protection, even routine waves can scour out the roots and destroy marshgrasses.
If there is still erosion, the reefs serve as a reverse revetment and recapture, in the low energy zones behind them, displaced soil.
The newly planted marshgrass on the newly constructed backfill widens any existing marshgrass along the shore or re-introduces it to create a solid root base consistently across the waterfront. The grasses themselves also disapate any high waves passing over them.
The vegitated soil line will now even cover any escarpment base such that undercutting and collapse of banks are eliminated.
Economic?
Economic results are:
1. maintenance of valuable waterfront property for the owner. Reduction of storm related losses.
2. maintenance of the communty tax base. Waterfront property is often the highest producing tax base for many communities. Damaged properties often are not easily restored or stay viable with damage to septic systems or drain fields, for example. Whole waterfront communities are facing destruction from storm surge and subsequent erosion that will affect the wider community in which those property owners live.
3. mainteance of water depths just offshore is vital for maintaining commercial and recreational access to the water. As creeks silt in from slumping shorelines, the waterfront can literally become too shallow for boating. The recreational fishing market is actually five times larger than the commercial fishing market. Since dredging is not normally a solution allowed for private docks, it becomes a viable option since the fill is being used to promote marshgrass growth and oyster habitat that mitigates any potential damage from dredging.
4. improvement maintenance of water quality. Sediment in the water column is one if the most serious factors in the low quality rating of waters like the Chesapeake Bay. Submarine aquatic vegitation is suffering from smothering sediments and the loss of light at the bottom that is vital to photosynthesis. Biodiversity is suffering as a result with the resulting loss of natural habitats. The economic benefit of clean water is vast. Commercial and recreational activities are multi-million dollar industries. Tourism is dependant on successful interaction with the water. Imagine the tourism value of a Carribean clear Chesapeake Bay, like the one Captain John Smith found. He documented seeing his anchor down 30' in the water column. Whole activities like diving and snorkeling would return. Fishing would improve.
Environmental?
The environmental upgrades resulting from creating stable shorelines, even in storm surge events are:
1. Reduced sedimentation into the water column from currently exposed shoreline soils.
2. Improved resistance to land run off (typically polluted) because of a healthy marshgrass buffer zones along the shore.
3. Improved water quality because of the living sill populated with oysters and mussels. Oysters are voracious filter feeders, primarily removing algae, which is other major contributor to Chesapeake Bay turbidity, for example.
4. Improved habitat for many other species in the reef and intertidal zones, helping to reverse the trend of lost bio-diversity.
5. Greater opportunity for the shoreline to evolve upland if sea level continues to rise, with the living sill growing correspondingly taller and wider.
6. The living sill will capture nitrites/nitrites in oyster shell.
What were the negative or unintended impacts (if any) associated with implementing this solution?
Oysters shells are sharp and hard. People must learn to give an active reef a wide berth, both in swimming and in boating. Other hazards are certainly respected such as sand bars, buoys, crab pots and their lines, gill nets, etc. Shoreline oyster reefs will be a new one, but certainly at the margins of waterways and mostly in private riparian rights areas.
Sometimes it takes a while before a living shoreline project can consolidate itself. Rains can wash out recently planted plugs. Geese are voracious eaters of young tender marsh seedlings. Losses of plants at this stage can be costly and discouraging. Storms before plants are able to hold the soil down can disrupt the backfill zone. Rip rap and bulkheads work instantaneously, while it takes patience for a living shoreline to mature to full protection mode.
Poaching of oysters is an ancient frustration for growers of oysters. They are a valuable commercial product that just grows out there for anyone to take! VA Marine Police have had to become very active with new laws that have increased penalties to try to stop this problem.
Return on Investment: How much did it cost to implement these activities? How do your results above compare to this investment?
This project, with its various customizable aspects, is easily reproduced and applicable to the vast majority of marine shoreline. Large scale reefs are even appropriate for land fronted on the ocean or large bays where wave heights can be extreme. These structures are being made and put in pilot sites with high wave energy.
The majority of shoreline is in the estuaries in their byzantine configurations. Here is where the solution of shoreline reefs will have its double benefit: protecting the shoreline during storm events while also providing habitat for marine species during normal times. Oysters filter the water, removing the other major water quality degrading factors: algaes and pollutants. Their habitat also becomes home and haven for many other species (crabs, shrimp, bloodworms, jellies, sea squirts, mussels, etc.) and foraging predators like herons and game fish.
Many State and Federal Agencies are working to establish deep water brood stock reefs for oysters at the mouths of major river systems in the Chesapeake Bay. However, unless habitat is re-introduced upriver for the larvae from these reefs to have a place to successfully strike, it will be difficult to reach the golden prize of oysters becoming a self-sustaining species once more. There is simply not enough habitat and parent shell available to expand the numbers of native oysters. Fossile shells are being mined, as opposed to new larvae becoming spat and then growing into oyster rock.
More affordable than rip rap and bulkhead, shoreline biogenic reefs are vital to efforts to restore large scale bodies of water, like the Chesapeake Bay, to good health and stability.
What are the main factors needed to successfully replicate this solution
Factors needed:
1. Demonstration sites to help educate the public about living shorelines. Local goverments that have done demonstration projects in their community have had high success rates in inverting request % rates for bulkheads/rip rap vs living shorelines.
2. Educated local Wetlands Board members, Planning Departments, and state government officials in regulartory capacities. For example, the state of VA has made Living Shorelines the "preferred" shoreline control methodology, but it is still a largely unknown alternative for people seeking help with their shorelines.
3. Educatioin to show waterfront property owners that they have stewarship responsibilities for the waterways their land abutts. The status of their shoreline affects everyone who is touched by that waterway and the waterways attached to it, etc. Taking action is less expensive than dealing with the consequences over the long term
4. More educated marine contractors who will advance this solution as a first choice solution vs traditional methods.
5. More aggresive financial support, such as low cost loans, for Living Shoreling projects at the local level, such as exists for replacing defective septic systems, underground storage tanks, etc.