Water agencies and cities across the Bay Area are preparing for another significant drought, bringing back mandatory water rationing and raising all-too-familiar concerns over dwindling water supplies.
And while the recent dry spell will mean shorter showers and yellow lawns, California's latest drought emergency doesn't appear to be a factor in Mountain View's plans to grow over the next two decades. With the backdrop of two successive dry winters and statewide drought declarations, city officials believe water demand is still low and flexible enough to support a vast increase in new residents and jobs.
City Council members are expected Tuesday to approve the city's Urban Water Management Plan, a key document detailing how Mountain View plans to provide enough water for residents in the face of uncertainty. Droughts are getting worse, likely as a result of climate change, and water providers for Mountain View like the San Francisco Public Utilities Commission (SFPUC) are raising alarm bells over future supply shortages exceeding 50%.
Meanwhile, the city's population is expected to balloon by 47% to 117,000 residents by 2045, along with a similar spike in employment of 28% to 126,000 jobs. Demand for water will likely increase by 35% over that period, according to city staff. Housing currently soaks up a majority of the city's water use at 58%, followed by irrigation at 24%.
Despite the dual threat of extended droughts and growing demand, the plan shows positive signs that suggest Mountain View can handle both. The first sign is that Mountain View, in general, uses less water today than it did in past years regardless of steady population growth. Historical water use peaked in the 1980s at over 16,000 "acre feet" per year, or about 5.2 billion gallons, compared to just 9,856 acre feet today.
The second sign is that Mountain View has a strong track record of ratcheting down water consumption in the face of droughts. Water use plummeted between 2013 and 2015 amid a historic drought and tight restrictions on water use and irrigation. City officials say Mountain View achieved a whopping 29% reduction in water use during the peak of the recent drought, and that water use has yet to return to 2013 levels.
The question looming over the plan, however, is whether the SFPUC is going to close the spigot. The regional water supplier, which accounts for 84% of Mountain View's water, is taking an unusually conservative approach to drought planning, making water shortage assumptions based on a lengthy eight-and-a-half-year drought. The plan is modeled on a hypothetical repeat of California's drought from 1986 to 1992, followed immediately by the drought from 1976 to 1977, raising eyebrows about how realistic those assumptions are.
"It does seem a little bit extreme to bookend the two worst-case scenarios together and then have that end up being something that's considered a likely outcome," said Councilwoman Sally Lieber at the May 25 council meeting.
Also fueling the SFPUC's conservative approach to drought planning is pressure from the state. California's Water Quality Control Plan for the San Francisco Bay/Sacramento-San Joaquin Delta Estuary -- better known as the Bay Delta Plan -- seeks to reduce how much water can be siphoned from the San Joaquin River in order to protect fish habitat along the river's tributaries.
Under both these assumptions, Mountain View could see its supply from SFPUC shrink by anywhere from 36% to 54%, though the numbers are not set in stone. Not only is the utility seeking to mitigate the problem with storage expansion and more recycled water, but both the Bay Delta Plan and the SFPUC's pessimistic drought model are hotly debated and subject to change.
Councilwoman Lisa Matichak said the city's water management plan, still clouded with uncertainty, should be approved even if it must be revisited once cities and the SFPUC sort out the right approach to balancing regional water needs with environmental protection.
"I think for now it's the best approach we have," she said.
Meanwhile, the Santa Clara Valley Water District -- which provides about 10% of Mountain View's water -- is expected to adopt an emergency water shortage declaration on Wednesday, June 9, along with mandatory water use reductions for county residents. The reduction is expected to be a 15% cut compared to 2019 usage. Valley Water officials say 2021 has been the third-driest year on record since 1977, and that snowpack statewide has been "virtually gone" since mid-May.
At the height of the last drought, the water district put out an aggressive campaign to get residents to reduce water usage, including fines for water wasters flouting the water use restrictions.