As Sacramento-area water agencies have pushed back against the state’s plan for mandatory water cutbacks in recent weeks, a recurrent theme has been climate: The proposed rules, they argue, are inherently unfair because it takes far more water to sustain a similarly sized patch of grass in Sacramento than it does in coastal communities such as San Francisco.
As the rules are currently framed, communities that tend to be high water users in summer are those that have to cut the most. Nearly half the water agencies in the Sacramento region are targeted for the steepest cuts proposed by state regulators – 36 percent – with the rest facing slightly lower mandates. The region essentially is being punished, local water leaders said, for its withering summers and famously dry heat, while coastal communities are rewarded for their more moderate climes.
The Association of California Water Agencies, a broad-based organization that represents water districts throughout the state, laid out a similar argument in a lengthy letter to state water regulators last week. The group urged the state to take factors such as sunshine, heat and humidity into account when mandating how much water each California community must conserve in response to the drought.
ACWA provided the board with a detailed breakdown showing relative water use after adjusting for climatic factors. When adjusted for climate, the data showed, the sizable gap in per capita water use between many coastal and inland water agencies narrowed considerably.
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“The targeting needs to be more evenly balanced across the state,” said David Bolland, ACWA special projects manager.
For now, the State Water Resources Control Board has shut the door on the climate discussion. Its latest draft regulations, released Tuesday, include no adjustments for the state’s climatic variances and continue to target communities that used the most water per capita last summer for the steepest conservation targets.
The reasoning, board officials said, is pretty straightforward: The heavy summer water use in inland communities such as Sacramento is largely due to people using water to sustain lawns and other landscaping choices that would not normally survive an inland summer. Adjusting for climate would take away impetus for inland areas to conserve water by planting landscapes more suited to hot, dry conditions.
“Our focus is on reducing outdoor water use,” water board scientist Max Gomberg said. “We needed to focus on the areas with the highest outdoor water use.”
The bulk of annual household water use in the Sacramento region is applied to landscaping, said Ellen Hanak, director of the Water Policy Center at the Public Policy Institute of California. That is partly due to the relatively large size of the region’s lots and its penchant for lush lawns. But she agreed climate is also a factor.
Evaporation removes about 33 inches of water annually from each square foot of grass in much of San Francisco, but about 57 inches from a similarly sized patch in Sacramento, according to researchers at the California Department of Water Resources. The disparity can be explained by a process called evapotranspiration: the loss of water due to soil evaporation and plant transpiration.
In transpiration, water moves through a plant’s roots, is secreted through small pores in its leaves and vaporized in the atmosphere. In soil evaporation, water goes straight from the soil to the atmosphere. Weather plays a large role in the process. Areas with abundant sunshine and high temperatures have higher rates of evapotranspiration.
“No patch of grass really exists in a vacuum,” said Amy Talbot, water efficiency program manager for the Regional Water Authority, which represents the interests of more than 20 Sacramento-area agencies. Climate, she said, is “kind of out of control of the water agency,” and a conservation plan that doesn’t account for it is “less equitable.”
Einar Maisch, general manager of the Placer County Water Authority, agreed. “If you have a yard in our region and you have a yard in the North Coast, the same yard requires more water. (Sacramento-area residents) using water in an identical way have higher per capita water usage.”
State water officials counter that such arguments miss the point: As the state enters a fourth year of drought, they say, residents need to rethink gardens to suit native conditions.
Hanak, with the Public Policy Institute, agreed. Inland California residents, in particular, need to shift their attitudes about lawns, she said. The water board’s proposed regulations provide “a very good reason for changing landscapes.”
“It’s more about getting rid of lawns that are only there to look good, and shifting to drought resistant plants,” she said.
Last month, citing unprecedented drought conditions, Gov. Jerry Brown ordered urban water agencies across California to cut urban water use, on average, by 25 percent over 2013 by next February. The board’s draft framework for carrying out that order divides the state’s 411 urban water agencies into nine tiers, based on their per capita water use between July and September last year. Each tier is assigned a mandatory conservation target, ranging from a 4 percent cut to a 36 percent cut, with the biggest water users targeted for the biggest cuts.
As proposed, 10 of the Sacramento region’s 23 water districts would need to cut water use by 36 percent this year. All but two Sacramento-area communities would have to cut usage by at least 28 percent over 2013 levels.
Adjusting water conservation targets for evaporation rates would be an “incredibly complex” process, said State Water Board Chair Felicia Marcus.
Simple math also plays a role: The San Juan Water District in Granite Bay, one of the state’s thirstiest, reported using 477 gallons per person per day last summer. By comparison, San Francisco used about 45 gallons per person per day during that time frame. Making a household that consumes nearly 500 gallons of water each day cut use by 20 percent saves more water than making a household that uses less than 50 gallons a day cut use by 20 percent.
In a way, Marcus said, climate “is in essence taken into account,” because inland districts are forced to cut by a large amount but generally not required to drop their per capita water use to the levels seen along much of the coast.
Persuading inland residents to transform their landscaping en masse “is not something that can easily happen overnight, as this switch requires investments,” Hanak said. Nor will it suddenly shrink inland lots, which tend to be larger than coastal lots.
But residents still can pay attention to how much water they put on their yards, Hanak said.
“If you can get people to reduce overwatering, you can get quite a bit of savings,” she said. “There is room for that in the short term without changing landscaping.”
Call The Bee’s Phillip Reese, (916) 321-1137.