Watershed Health Monitoring post 2020 Project, Washington State Department of Ecology

Ecology's Watershed Health Monitoring (WHM) project collects data on river and stream health by region and has done so since 2009. Beginning in 2021, a new master sample based off of NHD 1:24000k was used.
The goal of this project is to provide quantitative, statistically valid, and consistent estimates of the status and trends in physical, chemical, and biological conditions of Washington's rivers and streams across multiple scales and is based on a probabilistic study design.