The adaptation strategies below offer possible ways to address increased frequency and intensity of droughts.
- Build infrastructure needed for aquifer storage and recovery
- Increasing the amount of groundwater storage available promotes recharge when surface water flows are in excess of demand, thus increasing climate resilience for seasonal or extended periods of drought, and taking advantage of seasonal variations in surface water runoff. Depending on whether natural or artificial aquifer recharge is employed, the required infrastructure may include percolation basins and injection wells.
- Diversify options for water supply and expand current sources
- Diversifying sources helps to reduce the risk that water supply will fall below water demand. Examples of diversified source water portfolios include using a varying mix of surface water and groundwater, employing desalination when the need arises and establishing water trading with other utilities in times of water shortages or service disruption.
- Increase water storage capacity
- Increased drought can reduce the safe yield of reservoirs. To reduce this risk, increases in available storage can be made. Methods for accomplishing this may include raising a dam, practicing aquifer storage and recovery, removing accumulated sediment in reservoirs or lowering water intake elevation.
- Install low-head dam for saltwater wedge and freshwater pool separation
- Rising sea levels, combined with reductions in freshwater runoff due to drought, will cause the saltwater-freshwater boundary to move further upstream in tidal estuaries. Upstream shifts of this boundary can reduce the water quality of surface water resources. The installation of low-head dams across tidal estuaries can prevent this upstream movement.
- Finance and facilitate systems to recycle water
- Recycling greywater frees up more finished water for other uses, expanding supply and decreasing the need to discharge into receiving waters. Receiving water quality limitations may increase due to more frequent droughts. Therefore, to limit wastewater discharges, the use of reclaimed water in homes and businesses should be encouraged.
- Practice conjunctive use
- Conjunctive use involves the coordinated, optimal use of both surface water and groundwater, both intra- and inter-annually. Aquifer storage and recovery is a form of conjunctive use. For example, a utility may store some fraction of surface water flows in aquifers during wet years and withdraw this water during dry years when the river flow is low. Depending on whether natural or artificial aquifer recharge is employed, the required infrastructure may include percolation basins and injection wells.
- Develop models to understand potential water quality changes
- In many areas, increased water temperatures will cause eutrophication and excess algal growth, which will reduce drinking water quality. The quality of drinking water sources may also be compromised by increased sediment or nutrient inputs due to extreme storm events. These impacts may be addressed with targeted watershed management plans.
- 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.
- Implement watershed management
- Watershed management includes a range of policy and technical measures. These generally focus on preserving or restoring vegetated land cover in a watershed and managing stormwater runoff. These changes help mimic natural watershed hydrology, increasing groundwater recharge, reducing runoff and improving the quality of runoff.
- Encourage and support practices to reduce water use at local power plants
- The electricity sector, when compared with other sectors, withdraws the greatest amount of water in the United States. Any efforts to reduce water usage by utilities will increase available water supply. For example, utilities may provide reclaimed water to electric utilities for electricity generation, use closed-loop water circulation systems, or use dry cooling for the turbines.
- Model and reduce agricultural and irrigation water demand
- Agriculture represents the second largest user of water in the United States in terms of withdrawals. In order to forecast and plan for future water supply needs, agricultural irrigation demand must be projected, particularly in drought-prone areas. For example, to reduce agricultural water demand, utilities can work with farmers to adopt advanced micro-irrigation technology (e.g., drip irrigation).
- Model future regional electricity demand
- The electricity sector represents the largest user of water in the United States in terms of withdrawals. In order to forecast future water supply needs, changes in electricity demand related to climate change must be projected.
- Practice water conservation and demand management
- An effective and low-cost method of meeting increased water supply needs is to implement water conservation programs that will cut down on waste and inefficiencies. Public outreach is an essential component of any water conservation program. Outreach communications typically include basic information on household water usage, the best time of day to undertake water-intensive activities and information on and access to water-efficient household appliances such as low-flow toilets, showerheads, and front-loading washers. Education and outreach can also be targeted to different sectors (i.e., commercial, institutional, industrial, public sectors). Effective conservation programs in the community include those that provide rebates or help install water meters, water-conserving appliances, toilets, and rainwater harvesting tanks.
- Monitor surface water conditions
- Understanding surface water conditions and the factors that alter quantity and quality is an important part of projecting how climate change may impact water resources. Monitoring data for discharge, snowmelt, reservoir or stream level, upstream runoff, streamflow, in-stream temperature, and overall water quality can be incorporated into models of projected supply or receiving water quality.
- Develop emergency response plans
- Emergency response plans outline activities and procedures for utilities to follow in case of an incident, from preparation to recovery. Some of the extreme events considered in emergency response plans may change in their frequency or magnitude due to changes in climate, which may require making changes to these plans to capture a wider range of possible events.
- Update drought contingency plans
- Drought leads to severe pressures on the water supply. Drought contingency plans would include the use of alternate water supplies and the adoption of water use restrictions for households, businesses and other water users. These plans should be updated regularly to remain consistent with current operations and assets.
- 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.
- Retrofit intakes to accommodate lower flow or water levels
- In areas where streamflow declines due to climate change, water levels may fall below intakes for water treatment plants.
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.