Sterling Park Stormwater Recharge

The ASR well is located near a planned development on South Cooper Mountain in Beaverton, Oregon.

Stormwater runoff is problematic: It can overwhelm river flows and damage water quality by transporting pollutants to rivers and streams. GSI is evaluating a promising way of managing stormwater by storing it belowground in an aquifer and reusing it later for irrigation and other nonpotable purposes.

GSI completed a feasibility study that assessed the viability of storing treated residential municipal stormwater, collected during winter months, as a source for ASR. The stored runoff would be retrieved in the summer for nonpotable uses, such as irrigation or to reduce river temperatures in the summer with the cooler stored stormwater to improve habitats for fish and streamflow-dependent ecosystems. The 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 found that site conditions proved favorable; the Oregon Water Resources Department awarded the project grant funding to proceed with the pre-design and implementation phase.

GSI’s work involved:

  • 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.
  • Obtaining a grant to help fund the feasibility study.


Beaverton, Oregon


  • ASR
  • Stormwater Management

This innovative ASR application could play a critical role in balancing water demand in Beaverton as population growth continues, and potentially be used as a stormwater management tool statewide.

Photo Gallery

Stormwater sampling near the project site.

The "purple pipe" system will convey nonpotable irrigation water from the ASR well to nearby residential neighborhoods.

Stormwater sampling during a rain event.