said Tim Quinn, executive director of the Association of California Water Agencies. “My members have always stood up for that with local restora- tion projects where flow is always an element.”
Flows help define how well the Delta ecosystem performs, as well as the health of the many waterways that feed water to the system. It is a complicated relationship, filled with many variables, including the constant advance and retreat of saltwater from San Francisco Bay and the alterations to the natural system through human actions. Some scientists say it would be useful to alter the Delta’s highly struc- tured flow regime to one that better facilitates the recovery and restoration of native plants and fauna. “A key to restoring natural ecosystem functions – a central part of a reconciliation approach – is to reintroduce some of the variability in flows that better supported native aquatic habitat,” the Public Policy Institute of California (PPIC) said in a June 2012 report, Where the Wild Things Aren’t – Making the Delta a Better Place for Native Species. The authors recommend several new strategies to reconcile Delta habitat and flows.
A “reconciled” Delta would be managed “in a manner that might realistically achieve the … co-equal goals of water supply reliability and eco- system protection for the Delta as an evolving place,” according to the PPIC report, which notes that flow manage- ment “will have to become much more flexible, take place on shorter time steps, and account for hydrologic con- ditions spanning many years.” Changes to the Delta from human activity have suppressed the ecosystem to the point where its natural resilience “is a thing of the past,” said Bobker. “We are where we are because there has been a failure to balance,” he said. “We have evolved to the point where … we have legal protections for the ecosystem but for decades those values and legal requirements have not really been valued and discharged.”
July/August 2012
Flow management primarily entails the timing, magnitude and duration of pumping operations at the Central Valley Project’s (CVP) C.W. “Bill” Jones Pumping Plant and the State Water Project’s (SWP) Harvey O. Banks Pumping Plant. “Because of the effects of altered flows, including entrainment, managing flows within the Delta is an important tool for re- ducing the impacts of water diversions on fish,” says the Delta Stewardship Council’s final staff draft Delta Plan. Whether additional flows are needed for the Delta and where that water might come from is complicated. The CVP and SWP are currently re- sponsible for releasing sufficient stored water from upstream reservoirs to meet Delta water quality standards; and other upstream water users could be required to share in this responsibility. Environmental groups say the respon- sibility could extend to those currently not obligated to furnish flows, such as the Sacramento River settlement con- tractors, San Joaquin River exchange contractors and non-project water rights holders such as the Modesto Irrigation District, Yuba County Water Agency, East Bay Municipal Utility District or San Francisco Public Utilities Commission. Water users upstream of the Delta are concerned the state will look toward their interests in trying to answer the flow question.
“When I step back and look at this, there is an interesting conver- gence – the zeal for more flows [and] the interest to make exports more reli- able – that’s the classic debate going on in the Delta,” said David Guy, presi- dent of the Northern California Water Association (NCWA). “From a flow perspective, we know there are people that want to go upstream to look for additional water to help solve those problems and that is exactly what gets Northern California excited.” Concern extends to hydropower
producers, who depend on the right amount of water being available at the right time to generate electricity for the state’s power grid.
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“A key to restoring natural ecosystem functions – a central part of a reconciliation approach – is to reintroduce some of the variability in flows that better supported native aquatic habitat.”