Zachary C. Johnson
Research Hydrologist for the Washington Water Science Center
My research interests are at the intersection of watershed hydrology, ecology, biogeochemistry, water and land management, and fluvial geomorphology using field measurements, remote sensing, laboratory, and modeling techniques. I am particularly passionate about topics such as surface-subsurface exchanges, terrestrial-aquatic linkages, anthropogenic interactions, statistical and deterministic modeling, and the importance of spatial and temporal scale for watershed processes.
Science and Products
Tolt River Temperature Modeling
The Issue: The Tolt River and its tributaries, including the South Fork Tolt River, have recently experienced high water temperatures above water-quality standards. Water managers can regulate flows to influence the temperature regime of the South Fork Tolt River downstream of the dam. More information is needed to determine how far downstream water temperature strategies are effective. How USGS...
Puget Sound, WA Nutrient SPARROW Model
The Issue: Puget Sound watershed nutrient loads are known to have an impact on marine water quality along with wastewater treatment plants discharging to Puget Sound. To effectively reduce and control nutrient loads to the Sound, the Washington State Department of Ecology needs a regional watershed model that fits within their Puget Sound Nutrient Source Reduction Project’s management framework...
Science and Products
Tolt River Temperature Modeling
The Issue: The Tolt River and its tributaries, including the South Fork Tolt River, have recently experienced high water temperatures above water-quality standards. Water managers can regulate flows to influence the temperature regime of the South Fork Tolt River downstream of the dam. More information is needed to determine how far downstream water temperature strategies are effective. How USGS...
Puget Sound, WA Nutrient SPARROW Model
The Issue: Puget Sound watershed nutrient loads are known to have an impact on marine water quality along with wastewater treatment plants discharging to Puget Sound. To effectively reduce and control nutrient loads to the Sound, the Washington State Department of Ecology needs a regional watershed model that fits within their Puget Sound Nutrient Source Reduction Project’s management framework...