The Federal Emergency Management Agency proposed a rule on October 2 to establish agency procedures for determining whether any action as proposed is located in, or affects, a floodplain established under the Federal Flood Risk Management Standard of a 100- or 500-year flood, or other floodplain determination approach, or a wetland.
The proposed rule cited flood storage and groundwater recharge as activities that could occur in the floodplain but did not specify the types of structures that may be affected and lost in a flood.
The NGWA Managed Aquifer Recharge Work Group submitted comments on November 28 to recognize MAR-related structures for floodwater capture and groundwater recharge in the floodplain such as flood storage retention basins, spillways, injection wells, and other built systems that must be in the floodplain for their intended purpose of supplementing water supply.
The comments also noted that floodwater storage may continue to inundate floodplain areas beyond the time of the flood. Cautionary comments addressed the possibility of structures required under the Underground Injection Control regulations such as wells may be in the floodplain and that initial runoff (“first flush”) waters may not be captured for injection in the floodplain to protect the groundwater from contaminants picked up by early stormwater overland flow of a precipitation event.
Click here to read NGWA’s comments.