The U.S. Army Corps of Engineers’ (USACE) Institute for Water Resources (IWR) released a report on May 14 titled Managed Aquifer Recharge (MAR) and the U.S. Army Corps of Engineers: Water Security Through Resilience.
The report explains that with water needs increasing, water storage and flood risk management are needed, but major new surface infrastructure projects seem unlikely and water storage underground (managed aquifer recharge or MAR) is an alternative to augment surface storage.
MAR is a term that covers artificial recharge, aquifer storage and recovery, riverbank and riverbed filtration, groundwater banking, and other mechanisms of purposeful water recharge to aquifers for later recovery. MAR use has grown rapidly over the last two decades, progressing from an often-experimental concept to a management tool used in more than 1000 sites around the world.
The report states USACE and its partners have engaged, or are considering engaging, in the use of MAR in a variety of settings and purposes throughout the United States. These purposes include:
- Flood risk management — recharge of floodwaters in combination with surface storage to dampen the flood peak
- Aquatic ecosystem restoration — discharging stored groundwater may help maintain timely environmental flows
- Drought resilience — MAR can provide back-up storage for multiyear droughts without losses due to evaporation
- Saltwater intrusion prevention — replenishing coastal aquifers can provide additional agricultural and potable water supply while keeping saltwater at a safe distance
- Multipurpose projects — urban water projects can combine wastewater reuse, wetlands restoration, recreational and educational opportunities, and MAR.
The report goes on to examine how MAR has been, or could be, used in conjunction with USACE Civil Works water resources projects. It also summarizes some of USACE’s authorities for using MAR, provides numerous examples of USACE activities involving MAR, and considers how MAR can be integrated into new USACE initiatives.
The report is available as a free download in the IWR library.
MAR is one of four priority issues NGWA is focused on for the foreseeable future.