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Show PART II NATURE, USE AND MANAGEMENT OF WATERSHED LAND installed on irrigated land. About 3,000 diversion dams have been con- structed mainly to divert streamflow and provide runoff protection and reduce erosion on watershed lands. Land leveling improves the oppor- tunity for efficient use of water and reduction of return flow that carries pollutants into streams. Proper range use is important to maintain adequate cover for soil protection and improve the quantity and quality of desirable vegetation. About 8,000,000 acres are receiving proper range use. Brush and weed control is a practice that has been applied to over one million acres of range and pasture to increase vegetal watershed land protection and improve quality of water yield. Nearly 400,000 acres have been seeded with grasses. The supply of livestock water is vital to proper range use and local water storage furnishes some water- shed protection. Cooperative project-type programs The Watershed Protection and Flood Prevention Act provides for technical and financial assistance by the federal government to states or other qualified local organizations for land treatment, flood pre- vention, agricultural water management, recreation, municipal and industrial water supplies, and fish and wildlife developments on water- sheds up to 250,000 acres in size. The Act also authorizes the coordi- nation of related work of other agencies, including the Departments of Interior and Army. Projects under this Act include the planning and treatment of entire watersheds as resource units. Within the region five watershed protection and flood prevention projects are in operation or are nearing completion. In the Green River Subregion there are two projects: Boulder Lake and Ferron. Boulder Lake Watershed in west-central Wyoming is an agricultural water manage- ment project and supplies supplemental water to 8,620 acres of irrigated land. The Ferron Watershed Project, located in central Utah, is presently under construction. This multi-purpose project includes storage for irrigation water, fish and wildlife development, and provides flood protection for 12,000 acres of floodplain. Indian Wash and Roatcap Wash are flood prevention projects located in the Upper Main Stem Subregion in Colorado. The floodwater-retarding structure on Indian Wash provides protection to the eastern suburb of the city of Grand Junction. Structural measures on the Roatcap Wash Project provide flood protection to the irrigated farm area near the town of Olathe. 19 |