The adaptation strategies below offer possible ways to address increased frequency and intensity of erosion and sedimentation.
Adaptation strategies for erosion and sedimentation
- Use underground storage systems to detain runoff in underground receptacles
- Underground storage systems vary greatly in design. Underground storage systems detain runoff in underground receptacles that slowly release runoff. Often the underground receptacles are culverts, engineered stormwater detention vaults or perforated pipes. One of the benefits of underground storage is that it does not take up additional surface area and can be implemented beneath roadways, parking lots or athletic fields. Underground storage systems are typically designed to store large volumes of runoff and therefore can have a significant impact in reducing flooding and peak discharges.
- Use a retention pond to manage stormwater
- A retention pond is one of the earliest prototypes of green infrastructure and is now considered a more traditional type of stormwater infrastructure because it has been integrated into gray infrastructure design. It is an engineered stormwater basin designed to store runoff and release it at a controlled rate while maintaining a level of ponded water. Pollutants and sediment loads are reduced as the runoff is retained in the basin. Retention ponds are a very common stormwater management practice and may be designed with sustainable elements to increase water quality and decrease peak discharges. Vegetated forebays may be added to increase sediment removal as well as provide habitat. Another enhancement to traditional stormwater retention ponds is the addition of an iron-enhanced sand filter bench that removes dissolved substances such as phosphorus from runoff.
- Consider long-term benefits of green infrastructure in an economic analysis of stormwater management plans
- Train local appraisers/commissioners to capture the full value of green infrastructure. Incorporate co-benefits into ROI calculations, such as ecosystem services and quality of life factors.
- Create a regional sediment management (RSM) plan
- Develop adaptive stormwater management practices (e.g., promoting natural buffers, adequate culvert sizing)
- Develop a wetlands plan to determine which wetlands would be suited for restoration or preservation.
- Maintain Sediment Transport
- Promote wetland accretion by introducing sediment
- Prohibit hard shore protection
- Trap or add sand through beach nourishment – the addition of sand to a shoreline to enhance or create a beach area
Design a new coastal drainage system
- Harden shorelines with breakwaters – structures placed offshore to reduce wave action
- Harden shorelines with bulkheads – anchored, vertical barriers constructed at the shoreline to block erosion
- Harden shorelines with revetments that armor the slope face of the shoreline
- Harden shorelines with seawalls
- Control soil erosion in the watershed
- Water temperature benefits include keeping sediment from clogging streambeds and interfering with groundwater exchange and keeping heat-trapping particles out of waterways. Other benefits can include returning to natural sediment transport and geomorphology and raising water quality.
- Control stream bank erosion
- Water temperature benefits include keeping stream channels from getting wider and shallower and warming more easily. Other benefits can include maintaining natural sediment transport and geomorphology and raising water quality.
- Composite systems – incorporate elements of two or more methods (e.g., breakwater, sand fill, and planting vegetation)
- Create dunes along backshore of beach; includes planting dune grasses and sand fencing to induce settling of wind-blown sands
- Increase shoreline setbacks
- Plant submerged aquatic vegetation (such as sea grasses) to stabilize sediment and reduce erosion
- Redefine river flood hazard zones to match the projected expansion of flooding frequency and extent
- Remove shoreline hardening structures such as bulkheads, dikes, and other engineered structures to allow for shoreline migration
- Replace shoreline armoring with living shorelines – through beach nourishment, planting vegetation, etc.
- Restrict or prohibit development in erosion zones
- Use natural breakwaters of oysters (or install other natural breakwaters) to dissipate wave action and protect shorelines
These strategies are adapted from existing U.S. Environmental Protection Agency, Centers for Disease Control and Prevention and other federal resources. Please view these strategies in the context provided by the primary source document:
The adaptation strategies provided are intended to inform and assist communities in identifying potential alternatives. They are illustrative and are presented to help communities consider possible ways to address current and future climate threats. Read the full disclaimer.