GSI is evaluating the feasibility of a new way to sustainably manage stormwater using aquifer storage and recovery (ASR) technology.


Stormwater runoff is problematic: It can overwhelm river flows and damage water quality by transporting pollutants to rivers and streams. One promising way of managing stormwater is to store it below ground in the aquifer and reuse it later for irrigation and other non-potable purposes.

GSI’s Solution

Clean Water Services (CWS) and the City of Beaverton partnered with GSI to evaluate the feasibility of using stormwater for ASR. The study is assessing the viability of storing treated residential municipal stormwater, collected during winter months from residential streets. The stored runoff would then be retrieved in the summer for non-potable uses, such as irrigation or reducing river temperatures in the summer with the cooler stored stormwater to benefit both fish and streamflow dependent ecosystems. If feasibility is confirmed, stormwater would be recharged into an existing and currently unused ASR test well owned by the City, located next to a stormwater detention facility.

GSI’s work involves:

  • Collecting site-specific stormwater quality and quantity data
  • Evaluating treatment technology to address potential well clogging
  • Groundwater fate and transport modeling
  • Assessing regulatory and permitting issues
  • Developing an implementation plan

GSI also successfully helped CWS apply for a grant to help fund the feasibility study.

If this method proves feasible, it would help play a critical role in balancing water demand in the City of Beaverton as population growth continues, and could potentially be used as a stormwater management tool statewide.