Simulation of Fort Peck Lake Temperature Releases and Downstream Missouri River Temperatures
Abstract
Due to low annual runoff in recent years and low pool levels, the U.S. Army Corps of Engineers was unable to perform a mini-test followed by a full test of discharge and temperature enhancements to the Missouri River downstream of Fort Peck Lake. In lieu of actual flow and temperature enhancements, the U.S. Army Corps of Engineers, Omaha District performed computer simulations of both Fort Peck Lake and the Missouri River to analyze temperature conditions under flow/temperature enhancement operations. Temperatures in Fort Peck Lake and the Missouri River downstream of Fort Peck Dam were simulated using CE-QUAL-W2, a two-dimensional (longitudinal and vertical) water quality and hydrodynamic model for rivers, estuaries, lakes, reservoirs, and river basin systems. CE-QUAL-W2 was developed by the Environmental Laboratory at the USACE Engineering Research and Development Center (ERDC) in Vicksburg, MS. Baseline temperature conditions in the lake and river were developed through simulations of existing data; and, the sensitivity of parameters that influence lake and river temperature including lake inflow and outflow, pool elevation, and environmental temperature was determined. Simulations of spillway releases and selective tower withdrawals were performed to analyze the effectiveness of releasing warm water downstream to the Missouri River in order to meet the 18 deg C target temperature at Frazer Rapids, MT, as prescribed by the 2000 U.S. Fish and Wildlife Service Biological Opinion. In the baseline lake simulation 17 deg C temperatures, sufficient for meeting the 18 deg C temperature target at Frazer Rapids, MT, arise at the lake surface and spillway crest elevation between June 20 and 22 and persist for 96 days. Lake water near the existing powerhouse intake structure does not reach 17 deg C during any simulation year. The average simulated Missouri River temperature from June through August was 13.2 degC at Frazer Rapids with a peak daily temperature of 17.3 C.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 09, 2007
- Accession Number
- ADA635421
Entities
Organizations
- Omaha District, U.S. Army Corps of Engineers