The Nooksack River and its tributaries are crucial habitat for a range of aquatic life including populations of native salmonid species that are important to tribal members for cultural, subsistence, and commercial uses. The river also supplies water needs for residents, industries and farms of Whatcom County, including the city of Bellingham. The watershed has a long history of demand for water rights, flood protection and riparian use of the river that has altered groundwater exchange and total instream flows.
Western Washington is usually characterized by temperate winters with an abundance of precipitation and warm summers with little precipitation; however, with increasing temperature, climate change projections forecast that wintertime precipitation will increase and fall as rain rather than snow and summertime precipitation will decrease. Winter peakflow events are forecasted to increase in magnitude and frequency. The lack of water storage as snow through the winter will result in earlier spring peak runoff and an overall smaller peak that will then be exacerbated by lack of precipitation in the summer. Decreased summer streamflow and increased air temperatures will also give rise to increased water temperatures that are lethal to fish. These forecasted trends are already being observed in the Nooksack River watershed.
The Water Resources Program has been monitoring streamflow at a number of creeks throughout the watershed. In 2014, we initiated a project with the NWIFC to measure flow at Kenny Creek, Bells Creek, Todd Creek, and Deadhorse Creek during a 10-day period of no rain in the summer in order to determine how streamflow decreases naturally to baseflow levels. We also installed continuously recording stream gages at Hardscrabble Creek, Canyon Creek, Glacier Creek, and Sisters Creek to establish a baseline of streamflow and to assess future effects of timber harvest on flow. Stream gages have also been installed at Bagley Creek, Hadley Creek, Dobbs Creek, and Sholes Creek in order to assess glacier melt contribution to streamflow in comparison to snow-fed drainages. Stream velocity is then measured along a cross section of the creek to calculate the volume per time (e.g. ft3/sec, cfs), or flux, of water in the creek.
The datasets on streamflow is used in our efforts to distally model streamflow, stream temperature, and sediment dynamics to forecast the impacts of continued climate change on our water resources. We have contracted Western Washington University (WWU) and University of Washington (UW) to model these parameters, which is shares with water resources stakeholders in the Nooksack River watershed (Murphy, 2016; Truitt, 2018; Knapp, 2018)
Murphy, Ryan D., “Modeling the Effects of Forecasted Climate Change and Glacier Recession on Late Summer Streamflow in the Upper Nooksack River Basin” (2016). WWU Graduate School Collection. 461.
Truitt, Stephanie E., “Modeling the Effects of Climate Change on Stream Temperature in the Nooksack River Basin” (2018). WWU Graduate School Collection. 642.
Knapp, Kevin, “The Effects of Forecasted Climate Change on Mass Wasting Susceptibility in the Nooksack River Basin” (2018). WWU Graduate School Collection. 807.