Retired Water Manager Calls for Regional Swap
In an editorial in the Santa Cruz Sentinel on April 25, 2010, retired Santa Cruz Water Production Superintendent, James Bentley, wrote, “The City Council has been swayed into accepting a costly and environmentally unfriendly water solution when another viable and sustainable option exists which could minimize or eliminate the need for desalination.” The option Bentley refers to is the water swap with Soquel Creek District -- sending wet season water to Soquel in exchange for well water during drought.
Bentley participated in discussions of water supply options in the late 90’s that included this option detailed in the Alternative Water Supply Study (2000). That option was dismissed because the City was concerned that it would lose water diversion rights if it re-opened rights negotiations with the state. That concern is no longer an issue because the City has opened negotiations with National Marine Fisheries Service regarding fish habitat. Bentley calls for putting the water swap option back on the table. The following article includes a description of that option.
Making Use of Winter Flows
John Ricker, County Water Resources Division Director, is exploring two options that would make use of winter runoff to recharge aquifers and improve fish habitat in our streams. The first option is to divert water using existing City of Santa Cruz diversion and treatment facilities during high-flow periods in the San Lorenzo River to restore aquifer levels in Scotts Valley. That water would be used to reduce winter groundwater pumping in Scotts Valley and/or be infiltrated into abandoned quarries to recharge the Santa Margarita Aquifer, where the water is 200 feet below its historic level due to pumping by Scotts Valley. This recharge and in-lieu recharge would increase both groundwater storage and dry season base flow in the San Lorenzo River, improving fish habitat. Another approach in the same area would restore stormwater infiltration in developed, impervious areas of Scotts Valley to increase groundwater storage and reduce storm runoff.
The second option Ricker is exploring is for City of Santa Cruz to send treated surface water during high-flow periods to Soquel Creek Water District. During those periods the District could reduce its pumping of groundwater, thereby allowing the aquifer to recover. This option was considered in a study commissioned by the Santa Cruz Water Department published in 2000.1 That study included the possibility that in return for getting water from Santa Cruz during wet periods, Soquel Creek District would deliver well water to Santa Cruz during droughts. According to the study, “Limited use of the wells by the Soquel Creek Water District during winter periods – when supply could be augmented by the City – should reduce the stress on the aquifer and enhance natural recharge.”
Both options would require revision of the City’s water rights to divert water from the San Lorenzo River and possibly the North Coast Streams. Some of those rights date back to pre-1914, when the State didn’t require bypass flows to preserve fish habitat. Consequently, the City has a right to take unlimited water from the North Coast Streams. Its water rights to the San Lorenzo River at the Ocean St. Extension diversion have no minimum bypass flow requirements. Water rights for the Felton Diversion for diversion of high winter flows include minimum bypass requirements, but these may not be adequate, given the increased concern and greater understanding of fish flow requirements. In 2000, the Water Department did not pursue the option of a regional water swap with Soquel Creek District because of a concern that re-opening water rights would allow the State to require significant reductions in summer water diversions. According to Bill Kocher, Santa Cruz Water Department Director, this concern is no longer an issue, since the City has since entered into a process of developing a Habitat Conservation Plan that will modify its water rights to surface streams.
Despite the fact that the Habitat concerns are no longer at issue, Santa Cruz Water Department has not responded favorably to our request that this option be re-considered. According to Bill Kocher there option is not worth pursuing because the Purisima Aquifer is in overdraft and therefore Soquel Creek District would not be able to export water to Santa Cruz during a drought. Our response is that the agreement between Soquel District and Santa Cruz should include a provision that Soquel would match Santa Cruz’s curtailment during drought years. Then there would certainly be water available to deliver to Santa Cruz. For example, in a drought where Santa Cruz and Soquel are curtailing water use by 20%, Soquel could send 20% of its normal season well water to Santa Cruz. That’s the minimum Santa Cruz would receive. Once the aquifer reaches a level safe from salt-water intrusion, the potential to export water to Santa Cruz could be significantly higher.
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water diversion and other sources
I've been listening pretty carefully at the public desal meetings, and there were a few things that came up that this article is ignoring, but I think have to be addressed - and some that haven't been mentioned.
-Robert Curry's assessment that the University could supply its own water with wells drilled on Marshall Field was an interesting idea - but the speakers said that the obstacle was mainly political, in that North Coast farmers worried that UCSC's wells would draw from the same sources as theirs, thus depleting or at least reducing their own water supplies - and so the political will to fight them just wasn't there. That has to be addressed directly - if it's true, or countered properly if it's not. It would be a terrific solution.
-I live in the Soquel Water District, which has told customers that about a third of its water is about to be designated unusable because of high Chromium 6 levels.Discouraging in itself, that also means that there would be much less water for the Soquel District to send back to SC if Soquel were to get winter water from SC in an exchange. Another problem with the exchange is the question of storage - speakers stressed that they'd looked at all the available places for storage and none of them were available, do-able politically (like the quarry) or like building a big holding facility on Soquel Creek. So water received from SC during the winter would be used instead of drawing from aquifer water, yes, but it would have to be used right away, not stored, and there's a serious question of whether the recharged aquifer water would be sufficient to both keep out the salt water intrusion and still repay SC, given the third that Chromium will/has ruined.
-Pipelines - where will we get the money for this, and for right-of-ways? What other kinds of changes will be needed in the coming years of climate mess? Maybe all that should be tied together in a single project - changes for piping and storage cooordinated with swaps and planning for growth or lack of.
Thanks, Randa for raising the
Thanks, Randa for raising the issue of chromium 6 in the Soquel Creek Water District wells pumping from the Aromas Aquifer. If this contamination proves serious, it would require expensive treatment to remove the chromium. This certainly compounds an already unsustainable situation.
What we're proposing is a regional collaboration that could include resting Soquel District wells during winter months, making the situation there more sustainable. The potential for reciprocal water to go to Santa Cruz needs to be determined and the chromium 6 studies will have an impact. We need to support Ricker's investigation of this option. Currently the Soquel Creek Water District Board has directed their staff to investigate the options if desalination is not built. We think Santa Cruz needs to do the same. -Rick Longinotti, editor
p.s. The infrastructure for the water-sharing with Soquel Creek District is minimal compared to the cost of building a desalination plant. The lowest cost option would extend pipes from Santa Cruz storage facilities near Dominican Hospital to Soquel, and some new storage tanks in Soquel that could store a day's water usage.