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SSJID conserving water could hurt those relying on groundwater

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POSTED August 9, 2017 12:20 a.m.

Flood irrigation of the endless almond orchards surrounding Manteca, Ripon, and Escalon is an inefficient use of water. That is especially true when compared to the pressurized irrigation system that South San Joaquin Irrigation District made possible in District 9 south of Manteca and west of Ripon.
The pressurized system has sent water use tumbling, increased almond yields, reduced air pollution as gas powered pumps are no longer needed, cut fertilizer use, and has helped push back salt water intrusion in underground aquifers.
Expanding pressurized delivery systems seems to be just what the state wants done for “wiser” use of water. It is a costly proposition but in the long run pencils out. It would seem that bringing pressurized water delivery to the rest of the SSJID would be logical given the cry statewide for agriculture to reduce its water use.
There’s a problem, however. It might conflict with a state mandate to make sure underground water basins don’t pump more water than is restored during a given year.
That’s because all of that flood irrigation coupled with the SSJID canals that aren’t lined as well as Woodward Reservoir seepage recharge the underground water table. It makes the SSJID irrigation system a net water recharger of its sub-basin of the aquifer that those pumping water in Manteca, Lathrop, Escalon, Stockton, and rural areas including farms rely on.
What this means is simple. If SSJID becomes too efficient at conserving surface water it could put others that rely on well water in a world of hurt in two different ways.
If the de facto recharging SSJID does by default is reduced or eliminated, it would reduce the amount of water that basin pumpers can take out of the ground.
Even more serious is what it would do to rural residents and even farms that rely exclusively on well water.
Two years ago in northeast Ripon a farmer stopped flood irrigating his orchard given it was being removed to make more way for tract homes. Within the year neighbors saw their well levels drop substantially. It did not happen over the course of years. It happened virtually overnight. It is clear when SSJID growers stop flood irrigating they will no longer be helping neighbors counter their continuing draw down of the aquifer.
This presents an interesting problem for the SSJID.  If they opt to take steps to become what would arguably be the most water efficient irrigation district in terms of use in California, they could raise havoc with efforts for urban users and non-irrigation district farmers to continue pumping water without the ground basin authority being forced to go to a rationing or cap system.
Yet they have a duty to their customers that would benefit significantly by reducing surface water use in terms of saving money on everything from water and electricity to fertilizer as well as having the ability to increase yields.
Does the district go ahead and pressurize more of the delivery system and then recharge the groundwater table on purpose? That of course would create more expense.
Then there is another state edict — or at least one that was threatened during the drought — that Sacramento could seize without compensation any water that is saved for use elsewhere in California. That threat makes moving forward with pressurization precarious given water sales to other entities would be needed to finance pressurization. The SSJID would need assurances in the form of a state guarantee that the revenue source to finance a pressurized system won’t be pulled out from under them.
It illustrates what’s wrong with the fragmented approach that passes as state water policy. In a nutshell, they want irrigation districts to conserve more but then threaten to take away the key funding source to make pressurization efforts possible. Then they come along with an absolute groundwater conservation mandate that undermines efforts to conserve surface water.
Water Woodward when he picked out the site for the reservoir that the SSJID would eventually name in is honor was looking for a way to bring water to give life to the South County fields. He picked a location 21 miles to the northeast of Manteca that could capture water behind a dam and then allow the gravity flow of water to the farthest reaches of the fledgling district.  The site was chosen in 1915 and completed a year later.
Besides the fact the state today couldn’t even draft a request for proposals for an environmental study of a proposed dam site in the time it took the SSJID to pick a site for Woodward Reservoir and complete it, they certainly wouldn’t allow the creation of a 36,000 acre foot reservoir that does double duty as a groundwater recharger.
The soil beneath the reservoir is like a sieve, allowing more than 10,000 acre feet a year to soak into the ground and make its way to underground water tables.
While we need to conserve water and expand storage capabilities, it is doubtful given the state’s fragmented approach that has every water-related bureaucratic fiefdom issuing decrees in a vacuum that the best answer will ever see the light of day.

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