Developed Best Practices
In Coastal Virginia recurrent flooding can damage facilities and impede transportation of their workforce, materials and/or supplies. The adaptation and resilience strategies provided below focus on protecting facilities from the impacts of flooding, including recurrent flooding or flooding related to larger storm systems.
Companies that implement the strategies below can protect their business facilities, reduce flood risk, and restore operations quickly after a flooding event.
Practices for Waterfront Industries
Below are examples of cost-effective strategies to prepare waterfront industries for flooding.
These strategies were developed by the City of New York’s Department of City Planning after Hurricane Sandy devastated their waterfront industries.
Elevate power generators above the Design Flood Elevation (DFE).
Elevate on a concrete pad or steel platform.
$41,800 for concrete platform to raise.
Wet floodproofing includes measures applied to a structure or its contents that prevent or provide resistance to damage from flooding while allowing floodwaters to enter the structure.
$1,750 per flood vent.
Install the HVAC system on the building roof
1. Locating the HVAC system on the roof of a building to reduce the likelihood of exposure to floodwaters.
All pictures from Resilient Industry Mitigation and Preparedness in the City’s Industrial FloodplainDownload a PowerPoint summary of cost-effective strategies to prepare waterfront industries for flooding
Stormwater and Flooding Intervention Best Practices
Below are examples of cost-effective stormwater and flooding intervention strategies that include stormwater retention/filtration systems, and barriers for flood protection and intervention. These strategies were developed by the United States Environmental Protection Agency (USEPA) and Virginia Department of Environmental Quality (VA DEQ) and are located in the Virginia Stormwater Best Management Practice Clearinghouse and USEPA website.
Stormwater Retention/Filtration Techniques
It is possible to lessen the impact of stormwater quantity and quality by utilizing rainwater harvesting devices. As a consequence of this, the runoff will proceed at a slower rate, and the rainfall will be retained.Read More
It is possible to lessen the impact of stormwater quantity and quality by utilizing rainwater harvesting devices. As a consequence of this, the runoff will proceed at a slower rate, and the rainfall will be retained. Washing clothes, flushing toilets, washing cars, and watering gardens are just some of the many possible applications for the water that has been stored. Examples include rain barrels and cisterns.
Rain barrel costs vary based on size and amount of water retained. A small rain barrel will cost approximately $300 and a rain barrel that will hold 2500 gallons will cost approximately $2500.
Permeable pavements can absorb and store precipitation. Many varied materials can be used including pervious concrete, porous asphalt, and permeable interlocking pavers.
Cost: The costs of pervious concrete and permeable interlocking concrete pavers is $17-$21 per square foot.
Green roofs consist of growing media and flora, allowing for the infiltration and evaporation of runoff. They are commonly found on high and large industrial buildings, as well as some residential residences.
Barriers for Flood Protection and Intervention
A Self Closing Flood Barrier (SCFB) is a self-deploying wall that is constructed flush with the existing grade, and when flooding occurs, the water pressure will cause the SCFB to be activated automatically as a flood barrier.
Temporary Flood Walls/Barriers
Prior to flooding, temporary flood walls/barriers control and redirect water away from vulnerable structures and entrances. There are several types of temporary flood barriers and selection will be based be based on specific needs.Read More
Prior to flooding, temporary flood walls/barriers control and redirect water away from vulnerable structures and entrances. There are several types of temporary flood barriers and selection will be based be based on specific needs. For a list of FMIA Flood Barriers use this weblink: https://www.floodmitigationindustry.org/resources
Costs vary based on the type of barrier used, and height and length protection requirements.
Backflow Prevention Devices for Stormwater Piping
Backflow prevention devices for stormwater piping such as tidal check valves filter raw sewage, debris, sand, and mud during the flash flooding runoffs.
Shoreline Erosion Protection & Control Best Practices
Below are examples of cost-effective strategies to protect shoreline and control erosion with structural and natural and nature-based measures. These best practices were compiled from North Atlantic Regional Assessment Report developed by the Army Corps of Engineers Institute for Water Resources Baltimore District and the Shoreline Management in Chesapeake Bay report developed by the Virginia Institute of Marine Sciences
Seawalls and Bulkhead
Seawalls and bulkheads are comprised of structural reinforced concrete to withstand wave force. Vertical faces reflect wave energy and cause currents to scour the substrate at the structure’s toe. Thus, concrete seawalls and bulkheads reflect waves, preventing sand from settling on the water side.
Revetments frequently strengthen the beach by using rocks in an engineered design. Wave reflection and the resulting bottom scour are reduced by the sloping and roughed faces of stone revetments. Other substrates, like concrete, cloth bags filled with concrete, and gabion baskets, can also be used to build revetments.
In order to catch sediment carried by littoral transport, groins are frequent coast protection structures that are placed perpendicular to the shoreline and attached to the shore.Read More
In order to catch sediment carried by littoral transport, groins are frequent coast protection structures that are placed perpendicular to the shoreline and attached to the shore. Rubble is occasionally utilized, although they can also be composed of wood, rocks, sandbags, or gabions. A terminal groin is the structure in the groin field that is most downcoast, and multiple groins are typically constructed to promote beach sedimentation over a stretch of beachfront.
Natural and Nature-based Measures
Natural and nature-based measures to reduce shoreline erosion include redirecting tidal inlet characteristics, marsh fringe and dredging.
Dredging and Beneficial Use
Most North Atlantic harbors and ports’ main defense against shoaling (sediment accretion) is dredging. Shoaling slows down ship movements and has an impact on the local, regional, and global economies.Read More
Most North Atlantic harbors and ports’ main defense against shoaling (sediment accretion) is dredging. Shoaling slows down ship movements and has an impact on the local, regional, and global economies. One commonly accepted cost-effective method for addressing both accretion and erosion is to combine dredging operations (for bypass or navigational projects) with beach replenishment and wetland restoration (beneficial use).
With fetch exposures of less than 0.5 nautical miles, planted marshes are frequently employed to establish a protective fringe along low-energy shorelines, such as tidal streams.Read More
With fetch exposures of less than 0.5 nautical miles, planted marshes are frequently employed to establish a protective fringe along low-energy shorelines, such as tidal streams. A marsh fringe can develop along shorelines having higher wave energy due to marshes planted behind breakwaters and sills. The marsh fringe needs to be periodically replanted and maintained in environments with slightly increased wave intensity.
Beach nourishment is the practice of adding large volumes of beach-quality sand, dredged from nearby navigation channels or offshore shoals, onto beaches.Read More
Beach nourishment is the practice of adding large volumes of beach-quality sand, dredged from nearby navigation channels or offshore shoals, onto beaches. This protects people and property from damages from coastal storms by widening the beach and restoring eroding beaches. Beach nourishment projects are designed and engineered to work like natural beaches, allowing sand to shift continuously in response to changing waves and water levels.
Flood Mitigation Industry Association (FMIA) – a resource for building elevation, dry flood proofing and wet flood proofing. FMIA Resources include Federal Emergency Management Agency (FEMA) Technical Bulletins and Coastal Construction Manuals as well as a Flood Barrier Product List.Visit FMIA Resources