Paired watershed retrofit & restoration study

The City of Redmond is the lead agency on this multi-year complete watershed-scale stormwater retrofit effectiveness study.

There are seven watersheds in this study design:

  • Three application watersheds
  • Two reference watersheds
  • Two control watersheds

Application watersheds will undergo large-scale retrofits to bring the watershed into current Washington stormwater management standards. Control watersheds will progress at a normal timeline of development. Reference watersheds will not develop as they are in relatively protected environments.

All watersheds included in the study are located in and around Redmond. This project will monitor the streams draining these watersheds for various hydrologic, chemical physical habitat, and biological indicators.

Study question

  • How effective are watershed-scale rehabilitation efforts at improving conditions for receiving waters?

The study’s sampling quality assurance project plan provides information on the sites and study design.

Study findings

This effectiveness study will span 10 years, currently the first three years of monitoring are funded through Stormwater Action Monitoring (SAM).

Project tasks and deliverables

Due to the extended timeline on this project, only the most important tasks and deliverables are summarized.

Planning and preparation deliverables:

Water Year Final Reports:

The appendices contain multiple incremental deliverables such as the hydrologic summary, King County’s data quality assurance review, water quality summary, and sediment quality summary.