Ten New Bioretention Facilities to Monitor for Performance

By Bill Taylor

In 2016-17, Raedeke Associates lead a team that conducted hydrology performance monitoring of ten engineered rain gardens – “bioretention facilities” – throughout the Puget Sound Region.  These facilities occurred throughout the Puget Sound Basin, from Bellingham to Olympia, Poulsbo to Issaquah, and had been in operation for over the past 10-15 years.  The final report of the findings on the monitoring of these facilities is available on the Washington State Department of Ecology web site.

Now, with new funding, the Raedeke Associates team lead by Bill Taylor, and Clear Creek Solutions as the prime and modeling consultant, has begun monitoring of ten additional bioretention facilities located throughout the Puget Sound Basin.  Monitoring will continue through the wet season of 2018-19.

The important distinction of these new facilities to be monitored is that they were designed using the latest version of the Western Washington Hydrology Model v. 2012.  The goal of the study is to reveal how well these facilities perform at their inception, and how well they match the design model.

This monitoring is beneficial because it is able to reveal design and construction characteristics of the facilities that contribute to the expected performance of future designs.  These results will inform and give confidence to both engineers and local regulatory jurisdictions that these designs match the desired site-specific stormwater controls, as well as meet regional stormwater management goals.

For a summary of the Phase I Study of the original bioretention facilities, you can check out a summary from Washington Department of Ecology’s website here.