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Show PART III CURRENT WATERSHED CONDITIONS AND PROBLEMS, AND EFFECTS OF PROBLEMS The actual costs of fires are a combination of presuppression, suppression and rehabilitation costs, plus resource losses. The result of this complexity is that there is difficulty in developing an economic evaluation system applicable to fire costs. An adequately financed basic research and development program designed to produce reliable economic evaluation is needed to permit appraisal of oppor- tunities to lower acreage burned and reduce dollars of damage. Forest and rangeland damaged by fire need emergency treatment to reduce flood and erosion damage in and below the watershed after denudation by fire. The Sudden and complete denudation of large areas by fire poses a particularly serious threat to watershed and downstream values. Where fire consumes both the plant cover and the litter, the soil is wholly unprotected. Infiltration is decreased, overland flow occurs, and erosion is accelerated. Damage from floods and sediment deposition may occur both locally and downstream, but this damage can be reduced by emergency land treatment. Salinity The total salt burden in the Colorado River at Lee's Ferry is estimated to be 8.2 million tons per year. About two-thirds of the salt comes from natural sources while the other third is attributed to man-made sources. Conventional methods of wastewater treatment do not remove dissolved mineral solids and removal would require costly desalination processes. It is estimated that the contribution of salts from irrigated land is about two million tons. This is of major significance and is an average annual load of about 1% tons per irrigated acre. The remainder of the salt burden which is considered to be of man-made origin is principally from mining, industrial, and municipal sources. The major source of salts can be termed to be "geologic" in nature and not related to man's activities in the watershed. Mining, industrial, and municipal sources contribute relatively minor salt loads in comparison to those from irrigated lands and natural sources. Effects of minimizing salinity problems will have limited benefits in the Upper Colorado Region. They will be localized to the areas where the problems exist. Overall water quality in terms of salinity, total dissolved solids or salt load, as applied to the surface water, is satisfactory. However, there is an eightfold increase in the long- term dissolved solids concentration between the headwaters-high mountain country and Lees Ferry, Arizona. The Lower Colorado and California Regions thus have the most to gain from any benefits from watershed management that results in improving this water pollution factor. |