The adaptation strategies below offer possible ways to address anticipated climate risks to residences, buildings and infrastructure in areas vulnerable to sea-level rise.
Adaptation strategies for sea-level rise
- Build flood barriers to protect infrastructure
- Flood barriers to protect critical infrastructure include levees, dikes, and seawalls. A related strategy is floodproofing, which involves elevating critical equipment or placing it within waterproof containers or foundation systems.
- Relocate facilities to higher elevations
- Relocating utility infrastructure, such as treatment plants and pump stations, to higher elevations, would reduce risks from coastal flooding and exposure as a result of coastal erosion or wetland loss.
- Allow coastal wetlands to migrate inland (e.g., through setbacks, density restrictions land purchases)
- Establish rolling easements
- Remove hard protection or other barriers to tidal and riverine flow (e.g., riverine and tidal dike removals)
- Incorporate sea level rise into planning for new infrastructure (e.g., sewage systems)
- Conduct sea-level rise and storm surge modeling
- Modeling sea-level rise and storm surge dynamics will better inform the placement and protection of critical infrastructure. Generic models have been developed to consider subsidence, global sea-level rise and storm surge effects on inundation, including National Oceanic and Atmospheric Administration's Sea, Lake and Overland Surges from Hurricanes (SLOSH) Model and The Nature Conservancy's Coastal Resilience Tool, amongst others.
- Model and monitor groundwater conditions
- Understanding and modeling groundwater conditions will inform aquifer management and projected water quantity and quality changes. Monitoring data for aquifer water level, changes in chemistry and detection of saltwater intrusion can be incorporated into models to predict future supply. Climate change may lead to diminished groundwater recharge in some areas because of reduced precipitation and decreased runoff.
- Model and reduce inflow/infiltration in the sewer system
- More extreme storm events will increase the amount of wet weather infiltration and inflow into sanitary and combined sewers. Sewer models can estimate the impact of those increased wet weather flows on the wastewater collection system and treatment plant capacity and operations. Potential system modifications to reduce those impacts include infiltration reduction measures, additional collection system capacity, offline storage or additional peak wet weather treatment capacity.
- Study response of nearby wetlands to storm surge events
- Coastal wetlands act as buffers to storm surges. Protecting and understanding the ability of existing wetlands to provide protection for coastal infrastructure in the future is important considering the projected sea level rise and possible changes in storm severity.
- Monitor flood events and drivers
- Understanding and modeling the conditions that result in flooding is an important part of projecting how climate change may drive change in future flood occurrences. Monitoring data for sea level, precipitation, temperature, and runoff can be incorporated into flood models to improve predictions. Current flood magnitude and frequency of storm events represent a baseline for considering potential future flood conditions.
- Develop coastal restoration plans
- Coastal restoration plans may protect water utility infrastructure from damaging storm surge by increasing the protective habitat of coastal ecosystems such as mangroves and wetlands. Restoration plans should consider the impacts of sea-level rise and development on future ecosystem distribution. Successful strategies may also consider rolling easements and other measures identified by the U.S. Environmental Protection Agency's Climate Ready Estuaries program.
- Integrate climate-related risks into capital improvement plans
- Plans to build or expand infrastructure should consider the vulnerability of the proposed locations to inland flooding, sea level rise, storm surge and other impacts associated with climate change.
- Incorporate consideration of climate change impacts into planning for new infrastructure (e.g., homes, businesses)
- Integrated Coastal Zone Management – using an integrated approach to achieve sustainability
- Land acquisition program – purchase coastal land that is damaged or prone to damage and use it for conservation
- Retreat from, and abandonment of, coastal barriers
- Implement saltwater intrusion barriers and aquifer recharge
- As sea level rises, saltwater may intrude into coastal aquifers, resulting in substantially higher treatment costs. The injection of fresh water into aquifers can help to act as a barrier, while intrusion recharges groundwater resources.
- Improve pumps for backflow prevention
- Sea level rise and coastal storm surge can cause wastewater outlets to backflow. To prevent this, stronger pumps may be necessary.
- 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
- 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 seagrasses) 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
- 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.