Submitted to: Federal Interagency Hydrologic Modeling Conference
Publication Type: Abstract only
Publication Acceptance Date: 5/15/2010
Publication Date: 6/27/2010
Citation: Garbrecht, J.D. 2010. Climate variability, soil conservation, and reservoir sedimentation [abstract]. Federal Interagency Hydrologic Modeling Conference, June 27 - July 1, 10, Las Vegas, NV. 2010 CD-ROM. Interpretive Summary: Abstract only.
Technical Abstract: Rivers carry sediments which, upon entering a reservoir, settle to the bottom. The process of deposition and gradual accumulation of sediments in the reservoir is referred to as reservoir sedimentation. As reservoir sedimentation progresses, the storage capacity allocated for sediment deposition will at some time be filled, and subsequent sediment deposition will encroach upon reservoir storage capacities provided for other purposes. The rate of reservoir sedimentation can be slowed and date at which encroachment begins can be delayed by reducing sediment delivery to the reservoir. In this study, the integrated effects of upstream conservation measures and a climatic variation on sediment delivery to the Fort Cobb Reservoir in West-Central Oklahoma were investigated. The Fort Cobb Reservoir was constructed in 1958-59 by the US Bureau of Reclamation, receives inflow from a 787 [km2] agricultural watershed, and serves for flood control, municipal and industrial water supply, and recreation. Extensive soil conservation measures were implemented on the Fort Cobb Reservoir watershed over the last 50 years. Also, around 1985, a shifter to a wetter climate was observed. The available climatic, streamflow, and sediment data provided a unique opportunity to estimate the impact of the conservation practices and climatic variation on reservoir sedimentation rate. It was found that the reduction in sediment yield due to conservation practices was offset by an equal increase in sediment yield due to the wetter climate, and as a result reservoir sedimentation rates did not slow appreciably despite the implementation of conservation practices.