Tuesday, November 6, 2007 - 4:30 PM
145-9
Irrigation Rights, Salinity Obligations.
Salt management is a critical component of irrigated agriculture in arid regions like the western San Joaquin Valley (WSJV). This requires sustaining acceptable level of salinity in the crop root zone, subsurface drainage and a location to dispose drainage water, particularly, the salts it contains, which degrade the quality of receiving water bodies. Despite these needs, irrigation in the WSJV was started with insufficient attention to sustainable re-use or disposal of saline drainage water, and to salt disposal in general. The costs of regional collection of the drainage water and its disposal into San Joaquin Delta, or the San Francisco Bay , or the Pacific Ocean are extraordinarily high; the same is true for in-valley disposal, involving drainage water reuse to reduce drainage volume that must accommodate Se contamination. In response to water quality mandates by regional and state water quality control boards, farmers have begun implementing irrigation and crop management practices that reduce drainage volumes. Farmers and technical specialists also are examining water treatment schemes to remove salt or dispose of saline drainage water in evaporation basins or in underlying groundwater. To promote the most effective and least expensive solution to salt management, we suggest that the responsibility for salt management be combined with the irrigation rights of farmers. This approach will motivate water delivery agencies and farmers to seek efficient methods for reducing the amount of salt needing disposal and to determine methods of disposing salt in ways that are affordable and environmentally acceptable.
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