Hydrologic Information Center
Look up records for over 500 sites for continuous recording stream gages on rivers and streams, continuous recording rain gages, visually checked staff and crest stage gages in wetlands, lakes and detention facilities, recording and non-recording groundwater wells, and water quality sampling.

Flood Warning System Data
Read the current gage readings for major river systems across King County, and compare to historical records of past flood events.

Major Lakes Water Quality Monitoring Data
Small Lakes Water Quality Monitoring Data
Use maps to browse sampling sites for graphs and data of temperature, dissolved oxygen, pH, conductivity, nitrogen, phosphorus, chlorophyll, secchi depth, fecal coliform count, and E. coli count.

Swimming Beach Bacteria Levels and Water Temperature
Use a regional map to look up water quality graphs and data for about 30 swimming beaches at lakes across King County.

Streams and Rivers Water Quality Monitoring Data
Look up water quality data and graphs for streams and rivers including temperature, dissolved oxygent, pH, turbidity, conductivity, total suspended solids, phosphorus, nitrogen, bacteria, metals, precip, overall water quality index, and toxicity and pesticide studies.

Groundwater Data
View well logs and aquifer water quality samples as tabular data or using interactive maps.

Benthic Macroinvertebrate (Stream Bug) Monitoring
Learn why aquatic insect counts provide insight about the health of streams, and look up measures for many streams in King County, Washington.

Puget Sound Water Quality Monitoring Data
Download data and view graphs for Conductivity-Temperature-Depth (CTD) profiles for various mapped points and cast dates.