A bold initiative to take farm water conservation to the next level is being vetted by the South San Joaquin Irrigation District.
The first milestone of a year-long, $750,000 study on the feasibility of replacing canals serving 72,000 acres of farmland in Manteca, Ripon, and Escalon with a pressurized delivery system controlled by computers that would arm ditch tenders with tablets and growers with smartphones is being discussed during Tuesday’s SSJID meeting.
It would replicate the successfully pressurized system put in place in Division 9 south of Manteca and west of Ripon two years ago. The $14 million investment allowed growers who had been using groundwater with high salinity levels that can ultimately render soil sterile to take water instead from the SSJID system.
That coupled with a four-year investment of $4.5 million to help farmers throughout the district implement more efficient farming practices has saved the district over $3.5 million so far. Both the growers’ conservation program and the Division 9 pressurized system also saved enough water to allow SSJID to net $4 million more in out-of-district water sales to other water purveyors as of mid-2013.
The bottom line of such a system goes way beyond stretching water supplies. Although no cost has been generated so far, based on the Division 9 switch to it could push $100 million to implement a district wide pressurized system. The district could finance improvements through future sales of water it saves as well as from Tri-Dam Project power sales.
Among benefits the project would yield for farmers include increased crop yields, improved crop quality, reduced use of fertilizer and water, less energy use for pumps, reduced farm labor costs, reduced run-off, irrigation scheduling flexibility, improved air quality by eliminating diesel pumps, increased land values, and enhanced drought year resiliency due to less water use.
The project would also protect groundwater quality due to reduced leaching of fertilizers. It would reduce SSJID maintenance costs, conserve groundwater, allow the district to serve more farmers that currently rely on pumps, and would increase beneficial use of the district’s water rights.
Should the district ultimately switch to a pressurized system it would make more water available for domestic use in the cities of Manteca, Ripon, Escalon, Lathrop, and Tracy as well as free up more water for sale to other locations in California. It would effectively increase the district’s water supply by eliminating spillage as well as water waste. The pressurized system allows growers to use high efficient drip systems to get water to trees. Those closed systems also allow the intermixing of chemicals to further reduce costs and time by directing fertilizer and other nutrients directly to trees.
One potential drawback is a pressurized system could ultimately mean less water recharging underground aquifers. Some 40 percent of the 300,000 acre feet of the water the SSJID imports from the Stanislaus River watershed ends up recharging aquifers. Most of it is through seepage at Woodward Reservoir as well as from losses in canals and storage basins. But a sizeable amount is also attributed to flood irrigation. If pressurized delivery was available district wide, it would make the placing of drip irrigation financially feasible allowing flood irrigators to switch. Adequate pressure would mean growers wouldn’t need to employ expensive pumps that consume thousands of dollars of electricity monthly for even a relatively small almond orchard.
The Division 9 pressurized systems has significantly reduced pumping of all types cutting electricity use as well as air pollution since many farmers used diesel engines to operate pumps.
The board meets Tuesday at the district office, 11011 East Highway 120, just east of Manteca.