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w C,.o) t,.,,) ';;::l!; MAJOR SALINITY CONTROL ACCOMPLISHMENTS Since 1975, BLM has invested substantially in the study and control of salinity from both diffuse Cnonpoint) overland sources and point sources on BLM lands in the upper Colorado River basin. More than a dozen major studies were conducted from 1975 to 1982 to -quantify salinity yields from public lands, -identify salt transport mechanisms, -describe the effects of livestock grazing on salinity processes, and -describe the effects of coal mining on salinity processes. BLM salinity status reports issued in 1978, 1980, and 1984 summarize the results of these studies and describe salinity control strategies on the public lands. Appendix B lists BLM salini ty reports. Additional studies are needed to -quantify threshold conditions of marine shale stabilities to permit preventive conservation, -determine effectiveness of various land conservation practices in controlling salt yields and provide a basis for an economic evaluation of erosion control techniques, and -quantify salinity contribution from ground water flow. In 1983, BLM's emphasis shifted from studies to the identification and implementation of specific salinity control projects. BLM directed its offices in the upper basin States to identify issues and incorporate them in resource management and activity plans. Potential salinity control projects were identified for the Montrose, Grand Junction, Craig, and Moab Districts. A total of 12 activity plans in three different States have been completed and partially implemented since 1983, with salinity control as an objective. Two earlier plans have been inplemented in Arizona. The following map identifies the locations of each plan, and the associated table lists objectives, status, and types of controls. The cost effectiveness for the 12 plans ranges from $35 to $60 per ton of salt removed. Total implementation costs of the individual plans may be misleading relative to salinity reduction. Since the plans generally provide multiple resource benefits, the total cost exceeds the cost associated with salinity reduction. Most of the activity plans rely upon increased vegetation cover to reduce soil erosion and control salinity. Where annual precipitation is less than 12 inches per year, many years are required to verify cover objectives. Estimates of total completion and project verification times in years are included for each of the 12 activity plans. Development and implementation of additional salinity activity plans is dependent on resource management planning schedules and available funding. 17