SANTA CRUZ -- The city predicts the number of people living within its water service area could rise 10 percent by 2030 from levels seen in 2010, a quarter of which could come from increased enrollment at UC Santa Cruz.
Although university growth plans aren't known beyond the next eight years, another population will have a far greater impact on how much water is available much sooner than that.
State and federal regulators want the city to reduce diversions on the San Lorenzo River and North Coast streams -- where it gets about 85 percent of its water -- to improve spawning and raising habitat for the endangered coho salmon and threatened steelhead.
According to the National Oceanic and Atmospheric Administration Marine Fisheries Service, the population of California Central Coast coho was estimated at 6,000 spawning adults when listed under the federal Endangered Species Act in 1996. The population was estimated at 500 in 2010, a year during which only one or two male coho was observed in the Santa Cruz Mountains' streams, the agency reports. No juvenile coho have been observed in the river since 2005, though there are runs in Scotts and San Vicente creeks on the North Coast.
The federal agency's current demand for the city to leave 80 percent of natural flow in the river and streams has led to a shift in the public pitch for a controversial desalination plant -- one that places fish protection on par with safeguarding against drought. The city says the new flow standard is achievable in normal and wet years but not in dry years without a new water supply.
"I had no idea at the start that it would end up driving this thing," water director Bill Kocher said of negotiations with fish regulators that began 12 years ago. "When you sit down and look at whatever we have accomplished with water -- all the conservation we have achieved has been dedicated to fish. Now we have to decide what do we want to do (for people)."
Yet, the fish regulators won't back desalination, saying supply decisions should be left to city leaders.
"It doesn't matter to us what the solution is as long as the solution is reached," said Joyce Ambrosius, Central Coast supervisor for NOAA Fisheries.
Mike Taugher, a spokesman for California Fish and Game headquarters in Sacramento, said his agency would review the desalination proposal but doesn't believe it's needed.
"We think the city can meet the needs of its citizens and the flows for salmon with its existing supply," Taugher said.
FISH VS. PEOPLE
Fish need healthy stream flow for migration to sea, as well as healthy habitat in the river and creek beds for raising and spawning. The amount of water needed and available changes based on runoff and migration cycles -- and for some time the city hasn't been able to assign a figure to the 80 percent flow mandate.
However, the department earlier this month pegged the loss at 1 billion gallons annually on average, or about a quarter of what the system is capable of producing in good years. That would leave 3 billion for demand, which matches water use right now but would fall short of dry-year supply and will fail to accommodate growth.
Regulators are trying to figure out what to do about that a, and it isn't clear when the negotiations will be settled.
"Since you're not going to get (80 percent) in critically dry years, what are we going to require?" Ambrosius said. "We definitely understand when there is hardly any water in the stream, they can't produce more water and put it in the stream."
This spring, after receiving two-thirds of the average rainfall, the city began testing whether it could meet the flow standards while simultaneously asking customers to cut back 5 percent. Kocher said the system performed OK until early July, at which point the city had to increase diversions to avoid significantly drawing down the Loch Lomond Reservoir.
That is the kind of scenario in which a desalination plant could help by producing up to 2.5 million gallons of drinking water daily by removing salt from ocean water. The proposal sets up an interesting test for regulators.
In weighing a permit for the plant, the state Coastal Commission will look at whether the loss of small marine organisms when ocean water is drawn in presents a worthwhile trade-off. Is it acceptable to kill larvae and plankton on intake if the outcome may be more water left in the river and streams for salmon?
"That concept has been talked about a lot, but the commission hasn't been able to address it yet," said Tom Luster, the agency's desalination expert. "The whole issue in Santa Cruz is, is there a one-to-one relationship (if an organism is killed on intake but a fish saved in the river)?"
Al Smith of Corralitos, a retired member of the Monterey Bay Salmon and Trout Project working to restore coho habitat, said, "I don't see how we are going to be able to do a good solid fish culture without some level of desalination."
GROWTH IS KEY
Regulators also must evaluate whether the plant would replace lost water or simply add more to the mix. The answer may lie in how the agencies plan to handle growth, a projection that is a best guess based on housing goals, population estimates and development policies.
Rick Longinotti, a founder of Santa Cruz Desal Alternatives, said he doesn't believe the city has been transparent about how much water will be needed to serve its largest customer.
"They have downplayed the severity of fish habitat constraints on account of wanting to give more water to the university," he said.
Kocher rejects that notion, telling the City Council in a recent memo that "absent any additional growth, the shortfalls attributable to (fish flow), would not be materially different, meaning the long-standing problem has nothing to do with growth."
Santa Cruz has enough water to serve its 92,000 customers in normal or wet years, when the total annual supply is at least 4 billion gallons. But in multiple dry years, when the system produces between 2.6 billion gallons and 2.8 billion gallons, curtailment is required.
That problem clearly would be exacerbated by adding people. But is growth at UCSC really the problem?
The answer lies in balancing perspectives.
Of the roughly 360 million gallons in additional annual water demand projected for the city systemwide from 2015 to 2030, a fifth is expected to stem from UCSC, according to the 2010 Urban Water Management Plan's projections for demand reaching 4 billion gallons. The projected increase in demand from UCSC is just 5 percent less than the increase anticipated from single- and multiple-family residential combined.
"Is this desal project tied to university growth? Yes, absolutely," said former county supervisor Gary Patton. "(City officials) have committed to themselves that (desalination) is how they are going to provide the water."
The 151 million gallons of water used at UCSC in 2011 represents 5 percent of the city system's overall consumption but is 28 percent less than the campus used at its peak of 210 million gallons 15 years ago.
The university has requested 100 million gallons more annually to expand into undeveloped land north of the main campus. That amount represents a 66 percent increase compared to current use.
When viewed during drought conditions, however, UCSC's impact heightens. The 100 million gallons -- which will be offset at the university's cost elsewhere in the system -- would amount to 8 percent of what the city would be short during multiple dry years in 2020 if overall demand reaches the 3.8 billion gallons projected.
UCSC, whose growth plans are unknown beyond 2020, has not taken an official position on the desalination plant. But John Barnes, associate vice chancellor for physical planning and construction, noted the city's water supply can cover university growth in normal and wet years but can't meet demand systemwide in dry years. Therefore, he said the argument that desalination solely serves the university's aims "isn't terribly credible."
John Leopold, a county supervisor and member of the Santa Cruz Local Agency Formation Commission charged with approving the university water expansion, said he believes fish habitat negotiations and a decision about desalination should be completed before determining whether the water system can support growth.
"We're not doing it in a logical way," Leopold said. "We're doing it based on politics, which is not really the best way to make decisions about natural resources."
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PROJECTED GROWTH AND DEMAND
SANTA CRUZ WATER DEPARTMENT
Year Population Water demand
2010 92,165 3.1 billion gallons (actual use)
2020 97,793 3.84 billion gallons
2030 101,700 4.04 billion gallons
SOQUEL CREEK WATER DISTRICT
Year Population Water demand
2010 37,720 1.3 billion gallons (actual use)
2020 38,871 1.4 billion gallons
2030 39,550 1.3 billion gallons
SOURCE: 2010 Urban Water Management Plans, Santa Cruz and Soquel Creek Water District