Sediment transport in the western tributaries of the Sacramento River, California

摘要: The western tributaries of the Sacramento River, from Clear Creek in north to Putah south, drain an area more than 7,000 square miles. Major impoundments at present have a combined storage capacity about 2.5 million acre-feet, and proposed would add 3-7.5 acre-feet storage. About 960,000 water is imported region Trinity River annually, plans call for annual importation future 700,000-950,000 Eel basin. Most this will be conveyed areas deficiency south study area. quantity sediment carried by streams deposited them may affect both quality operational regimen reservoirs. Because these possible problems, data on transport been analyzed provide planners engineers with estimates quantities involved fluvial processes In basins studied, average yields suspended range less 100 tons 3,000 per mile, bedloads 2 7 percent total discharge. Suspended-sediment yield shows general correlation geologic province highest are draining Coast Ranges province, lowest Great Valley California intermediate Klamath Mountains province. Total probably 4.7 tons. A substantial part this, perhaps 30 percent, retained entrapment as deposits lakes reservoirs within ; remaining 70 transported regions, most it during relatively short periods high streamflow. INTRODUCTION Biver yield, large good-quality water. Extensive development area's resources either underway or planned (California Department Water Resources, 1970) control floods irrigation, recreation, municipal supply, wildlife enhancement. Each Jl J2 SEDIMENTATION IN SMALL DRAINAGE BASINS plan includes several impoundments, well other engineering works that subject report because available together need information concerning make separate appropriate. Sediment eastern tributaries.is low, basin has therefore posed fewer problems. limited not analyzed. This summarizes analyzes much gathered tributaries. Hopefully, provided here valuable design operation waterdevelopment system. sediment-transport characteristics important factor selection reservoir sites. deposition can shorten useful life reservoir, fine particles suspension cause persistent turbidity downstream. creation mainstream bring pronounced changes downstream processes. For example, trapping coarse leave unladen stream renewed ability erode, thereby result degradation channel; hand, reduction floodflows reduce gross competency aggradation sediment-sampling program conducted Resources Division U.S. Geological Survey cooperation Federal, State, local agencies, Survey's appraisal Nation's resources. Data collected course were used develop long-term was personnel Division, Survey, Resources. work under direct supervision Willard W. Dean, chief subdistrict, R. Stanley Lord, district charge water-resources investigations California. DESCRIPTION OF THE AREA north. area, 7,070 miles, shown figure 1. east flank southeastern tributary directly way one floodways which parallel river. sites listed table 1; locations SEDIMENT TRANSPORT SACRAMENTO RIVEK J3