WSP12980 - Laserfiche WebLink

Home Browse Search

I I I I I I I I I I I I I I I I I I I hour deliveries and increases in main canal unsteadiness. Additional irrigation flexibility in excess of the current 12-hour run program (which comprises almost 13.5 percent of all delivery events), thus has the potential to conserve additional water, but only if used in combination with other conservation projects. This is due to the increased operational discharge that generally results from flexible deliveries, which in conjunction with the current capacity limitations of the District's distribution system, will not allow changes in run-time alone. When implemented with the construction of additional mid-lateral reservoirs or interceptors though, alternative irrigation schedules can provide a viable means of water conservation and also prevent the increased lateral spillage deduction that was applied to the 12-hour delivery project. Two types of additional flexibility have been proposed: allowing 6-hour deliveries and "on- demand" run times. Similar in concept to the 12-hour program, 6-hour deliveries encompass flow orders with a six hour duration while "on-demand" deliveries allow for complete flexibility as to the (time) length of the water order. It is estimated that 6-hour deliveries will increase the use of non-traditional (non 24-hour) deliveries to 30 percent of all delivery events, and provide one-third more water savings than the 12-hour delivery program. On-demand deliveries are expected to increase the use of non-traditional (non 24-hour) deliveries to 40 percent of all delivery events, and provide one-sixth more water savings than the 6-hour run-times. Based upon conservation values from the current 12-hour delivery program, and when combined with water conserved through the capture of lateral operational discharge by the joint interceptor or mid-lateral reservoir projects, four variations of additional irrigation scheduling conservation costs can be derived. Six-hour and on demand runs only are estimated to conserve approximately 55,000 and 103,000 acre-feet, respectively. The 48,650 or 46,200 acre-feet of lateral discharge that the interceptor or mid-lateral reservoir would capture is added to these estimates resulting in the annual conservation value for additional irrigation scheduling flexibility with interceptors or mid-lateral reservoirs. Ending flows included in the earlier interceptor water conservation estimate are not included here because ending flows and additional irrigation scheduling flexibility both target tailwater. A major factor affecting water conserved by this project is water user management. Thus, a combination of studies to determine management practices and water user incentives to manage on-farm water use could result in as Draft: Subject To Revision 12/21/95 40