The Sac River basin is located in southwest Missouri with its headwaters beginning in Lawrence, Christian, and Greene counties and flowing in a northerly direction to its confluence with the Osage River and Truman Reservoir (Figure Lo01). The basin drains 1,981 square miles via 2,510 miles of streams (839 miles perennial; U.S. Environmental Protection Agency website, 2000) and all or part of 10 counties (Barton, Cedar, Christian, Dade, Greene, Hickory, Lawrence, Polk, St. Clair, and Vernon; Figure Lo02). Major tributaries are Turnback Creek, Limestone Creek, Little Sac River, Sons Creek, Horse Creek, Cedar Creek, Coon Creek, Brush Creek, Bear Creek, and Turkey Creek (Figure Lo03). Figure Lo04 delineates how the tributary sub-basins fit together to form the Sac River basin in Missouri. The Sac River basin is bound to the southeast by the James River Basin and to the southwest by the Spring River basin both of which are part of the Arkansas-White-Red River basin. It is bound on the west by the Clear Creek sub-basin of the West Osage River basin, and to the east by the Pomme De Terre River basin. To the north it drains into the Truman Reservoir sub-basin of the West Osage River basin.
Human population in the Sac River basin was 83,720 in 1990 (DuCharme and Miller 1996). Cities and towns found partially or entirely within the basin are Springfield, Willard, Republic, Brookline, Billings, Halltown, Miller, Strafford, Ash Grove, Everton, South Greenfield, Lockwood, Greenfield, Arcola, Milford, Jerico Springs, Umber View Heights, El Dorado Springs, Collins, Flemington, Humansville, Stockton, Fair Play, Bolivar, Aldrich, Dadeville, Morrisville, and Walnut Grove (Figure Lo05). Springfield is the largest municipality in the basin. The major roadways found in the Missouri portion of the basin are U.S. Interstate 44, U. S. Highways 54, 60, 65, and 160, and Missouri state highways 13, 14, 32, 39, 82, 96, 97, 123, 125, 174, 215, 245, and 266 (Figure Lo06). Many other smaller county roadways allow access to most parts of the basin. Urbanization, intensive animal based agriculture, and poor land use practices are the primary water quality related problems in the watershed.
The Brush Creek Inventory and Management Plan (Groshens 1997) focuses on the Brush Creek sub-basin and includes more detailed information and management objectives for that portion of the Sac River basin. These objectives include efforts to enhance stream and riparian habitats, efforts to improve water quality and information concerning the maintenance and improvement of native aquatic fauna and recreational fishing opportunities.