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Show PART III CURRENT WATERSHED CONDITIONS AND PROBLEMS, AND EFFECTS OF PROBLEMS Flood and sediment on cultivated and pasture land Flood and sediment damage is a problem on 348,000 acres of culti- vated and pasture land in the region. Approximately 42 percent of the affected area is in the Green River Subregion, 40 percent in the Upper Main Stem, and the remaining 18 percent is in the San Juan-Colorado Subregion. Upstream watersheds are subject to high intensity thunderstorms. Precipitation from these storms sometimes falls at rates greatly exceeding the infiltration capacity of the soils and there is surface runoff. Damages result from floodwater and sediment when this type of storm occurs on drainages above irrigated land. Storms during the harvesting period may damage harvested crops and the deposited sediment and debris reduces land productivity. Irrigation distribution systems are often damaged or filled with sediment. Other fixed improvements such as fences, buildings and roads are subject to damage. Flooding of this type is typical in the watersheds where detailed studies led to works of improvement under the Watershed Protection and Flood Prevention Act. Other Damages Fire on forest and rangeland Fire damage is an annual problem on approximately 27,000 acres of forest and rangeland. About 63 percent of the acreage is in the Green River Subregion, 26 percent in the Upper Main Stem, and the remaining 11 percent is in the San Juan-Colorado Subregion. The problem of fire on forest and rangeland centers on two unique factors -- (1) the low value per acre of typical vegetation on these lands and (2) their remoteness. Forest fires destroy timber and produce a devastated landscape, while rangeland fires do not usually alter the landscape appearance as noticeably. There is need for public education on the real costs of fires, not only in aesthetic damage and lost live- stock forage and wildlife habitat, but also in the costs of erosion and sediment production following the fires. With increasing numbers of persons using the federal land there has been a corresponding increase in the number of fires started. Fewer acres are actually burned than previously, however, due to improved fire fighting capability. The remoteness of many fires and the lack of roads to them sometimes causes long delays in reaching the scene. Federal agencies are attempting to achieve a maximum delay time of 60 minutes to any fire. This can be achieved by road construction and increased use of air facilities. 42 |