Water Quality in Keno Reach of the Klamath River

Science Center Objects

The Klamath River from Link River to Keno Dam experiences poor water-quality conditions on a seasonal basis, creating inhospitable conditions for fish and other aquatic organisms. These problems led the Oregon Department of Environmental Quality to prepare a Total Maximum Daily Load (TMDL) plan to bring the river into compliance with water-quality standards. This study uses a hydrodynamic and water-quality model to provide insight about how various management actions could affect water quality in the reach.

Water quality in the Link-Keno reach of the Klamath River was designated as “water quality limited” on Oregon’s 303(d) list for ammonia toxicity, arsenic, and dissolved oxygen criteria year-round, and pH and chlorophyll a criteria in summer. A total maximum daily load (TMDL) was approved by the U.S. Environmental Protection Agency in May 2012 and a revised version was released by Oregon Department of Quality in 2017 (Oregon Department of Environmental Quality, 2017). The TMDL specified nutrient and BOD5 load reductions for point and nonpoint sources along the Link-Keno reach. For example, the TMDL would require greater than 80-percent reductions in total nitrogen, total phosphorus, and BOD5 for the Lost River Diversion Channel and Klamath Strait Drain.

With the Lost River flowing through both California and Oregon, there are separate TMDLs for the California and Oregon sections of the river (U.S. Environmental Protection Agency, 2008; Oregon Department of Environmental Quality, 2017). In Oregon, portions of the Lost River and Klamath Straits Drain were designated as “water quality limited” on the 303(d) list for ammonia toxicity, arsenic, and dissolved-oxygen year-round and chlorophyll a, E. Coli, and pH (only Lost River river miles [RM] 25.4-27.6 for pH) in summer. Load allocations in the TMDL represent 50% reductions in dissolved inorganic nitrogen and CBOD and also require dissolved oxygen increases for the impoundments.

The U.S. Geological Survey (USGS), Watercourse Engineering, Inc. (Watercourse), and Reclamation have been collaborating since 2006 to develop knowledge and tools to better manage for water-quality in the Link-Keno reach and the Lost River.  This collaboration has led to enhanced water quality datasets (Sullivan and others, 2008; Sullivan and others, 2009; Goldman and Sullivan, 2017), understanding of fundamental water quality processes such as algal decay and settling (Poulson and Sullivan, 2010; Sullivan and others, 2010; Deas and Vaughn, 2011), the construction and enhancement of CE-QUAL-W2 water quality and hydrodynamic models (Sullivan and others, 2011, 2013, in preparation; Sullivan and Rounds, 2016), as well as model scenarios that provide insight into how future operations could affect water quality (Sullivan and others, 2012, 2014).