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N '0 W ~ . . . In the Grand Valley, studies of level-basin irrigation on two major soil types are nearly complete. The results indicate that level basins are a practical and effective way of applying surface irrigation water. About 1/3 of the irrigated lands in the Grand Valley have deep enough soils and flat enough slopes to allow practical basin leveling. Level-basin irrigation eliminates surface runoff, allows close control of deep percolation, requires no more energy than traditional surface irrigation methods, simplifies irrigation water management, and reduces labor requirements or can easily be automated. Yields of corn, alfalfa and small grains during five years of study have equaled and in some cases significantly exceeded Grand Valley average yields. The second year's data have been obtained from a study of crop water use from high, saline water tables. Results to date indicate that water tables 60 em and 105 em below the soil surface can contribute significantly to water needs of corn and alfalfa, even though the water is highly saline. Established alfalfa obtained all water needed for evapo-transpiration during 1982 from a 60 em water table. However, surface irrigation is still needed to prevent salt buildups at the soil surface. Methods of modifying irrigation SChedUling procedures to account for high water table contributions will be developed after additional data are collected. A final report has been issued in a cooperative study with CSU on design of irrigation pipelines to transport sediment laden irrigation water without excessive deposition, and on deSign of irrigation pipe turnouts from canals to minimize diversion of sediment into the pipelines. Another phase of the same study has evaluated techniques for minimum tillage of corn under graded furrow irrigati'on in the Grand Valley. E. Monitoring and Evaluation Monitoring and evaluation (M&E) activities have been extremely limited since initiation of the Uinta Basin 'and Grand Valley projects. The Utah Bureau of Water Pollution Control has recently completed a two-year monitoring program which essentially collected and established some baseline data. It included measurements on several stream sites, in return flow drainageways, and in some groundwater observation wells. The SCS also provided funding for limited irrigation water management field monitoring by CSU in the Grand Valley in the 1980, 1981, and 1982 irrigation seasons. This field monitoring was to evaluate some of the furrow irrigation design criteria, and to monitor results of several onfarm irrigation improvements to determine implementation needs or modifications which would be useful to the program. CSU was also to evaluate effectiveness on reducing deep percolation and Colorado River salt loading from several irrigation systems. Copies of the February 1982 report are available through SCS or ARS. Two significant 1982 monitoring activities included 1) the development of long-term monitoring plans from the Uinta Basin and Grand valley projects and, 2) the installation of a "popcorn" data collection site in the Uinta Basin for irrigation management schedules and monitoring purposes. The long-term monitoring plans were developed to provide a basis for staffing and funding monitoring activities to evaluate program implementation impacts on water management, deep percolation, and salt load reductions. The monitoring plan is designed to evaluate a cross-section of various onfarm irrigation systems and will serve as a basis to more accurately determine project impacts. Major components of the plans include onfarm irrigation evaluations, wetland and wildlife habitat evaluations, data collection and analyses, plus an economic evaluation component to be added later. 19 K N' c:t L "<0.;, k>:~