Temperature Modeling

Temperature modeling for 2009 as reported in the 2009 Annual Report:

2009 was a Dry Water Year that saw Trinity Reservoir drawn down to roughly 900,000 acre feet, or roughly 37 percent of capacity. Low reservoir levels can increase the temperature of the water released from a dam and jeopardize the ability to meet the downstream water temperature criteria. Temperature modeling of Trinity Reservoir, Lewiston Reservoir, and the Trinity River were run to evaluate several dam release scenarios and their impacts on temperature compliance in the river (Figure). Based on these model results, Reclamation used the deeper auxiliary outlet works to release colder water from Trinity Reservoir. This operational change resulted in successfully meeting the 13.3 °C temperature criteria at the North Fork Trinity River.
tempmodeling

Predicted river temperatures (º F) at Douglas City during July through September 2009 by the SNTEMP (Stream Network Temperature) model run in May, 2009. The upper line (Scenario 1) shows releases from the Trinity Dam Power House outlet. The lower line (Scenario 2) uses releases from a deeper, cooler stratum of Trinity Reservoir via an auxiliary outlet until September 15. The horizontal-stepped line is the maximum temperature limit for Douglas City. (60º F equals 15º C).

Suggested further reading:

Scheiff, T and Zedonis, P (2010) The influence of Lewiston Dam releases on water temperatures of the Trinity and Klamath Rivers, CA. April to October, 2009.

Faux, R (2010) Application of airborne thermal infrared (TIR) imagery to the understanding of spatial temperature patterns in the Trinity River. Oral presentation provided at the 2010 Trinity River Science Symposium

Wittler, R; Yaworsky, R; and Manza; P (2010) Temperature management of the CVP northern system. Oral presentation provided at the 2010 Trinity River Science Symposium

Zedonis, P (2009) The influence of Lewiston Dam releases on water temperatures of the Trinity and Klamath Rivers, CA. April to October, 2008.

Zedonis, P (2008) The influence of Lewiston Dam releases on water temperatures of the Trinity and Klamath Rivers, CA. April to October, 2007.

Watercourse Engineering (2007) Trinity River flow and temperature modeling project.

Stutsman, M R (2005) Mid-Klamath river salmonid health and abundance in response to a proactive flow release from Lewiston Dam on the Trinity River, California, 2004.

Zedonis, P and Newcomb T (1997) An evaluation of flow and water temperatures during the spring for protection of salmon and steelhead smolts in the Trinity River, California.

Vermeyen, T (1997) Use of temperature control curtains to control reservoir release water temperatures.

Search the Library in TRRP’s Online Data Portal for more.