Upper Klamath and Lost River Water Quality Monitoring and Modeling

Installation of acoustic Doppler instrument (Photo by M. Stewart, 4-Jun-2008)

The Klamath River from Link River to Keno Dam and Lost River experience poor water-quality conditions on a seasonal basis. The water-quality at sites in these reaches has been classified as "Very Poor" by the Oregon Water Quality Index. These problems led the Oregon Department of Environmental Quality to release nutrient and water temperature Total Maximum Daily Load (TMDL) plans to bring the river into compliance with water-quality standards. A TMDL is a plan for restoring impaired waters that determines the highest amount of a pollutant a water body can receive and still meet standards.

The nutrient TMDL specifies nutrient and BOD5 load reductions for point and nonpoint sources along the Link-Keno reach. For example, it requires greater than 80-percent reductions in total nitrogen, total phosphorus, and BOD5 for the Lost River Diversion Channel and Klamath Straits Drain. Load allocations in the Lost River TMDL represent 50-percent reductions in dissolved inorganic nitrogen and carbonaceous BOD (CBOD) and require dissolved oxygen increases for the impoundments.

The U.S. Geological Survey, U.S. Bureau of Reclamation, and Watercourse Engineering, Inc. are colloborating to develop knowledge and tools to better manage water quality in the Link-Keno reach of the Klamath River and the Lost River. This collaboration has led to enhanced water quality datasets, understanding of fundamental water quality processes such as algal decay, and settling, the construction and enhancement of CE-QUAL-W2 water quality and hydrodynamic models, as well as model scenarios that provide insight into how future operations could affect water quality.