In the lengthy march toward turning the Napa Pipe development from blueprints to buildings, one issue has gained increasing attention: its water consumption.
One hundred fifty-four acres of old industrial lands south of Kennedy Park are to become home to a Costco emporium, stores, restaurants, offices and up to 945 homes. The residents, business owners and employees coming to the mixed-use community all are expected to use water supplied by the city, which recently approved a water service deal with Napa Pipe’s developer.
But how much stress might the development’s new customers put on water supplies, in a city placed – like all other water-providing agencies in California – under mandatory use cutbacks since this spring?
Joy Eldredge, manager of the city Water Division, said the supply studies for Napa Pipe – which are required under the California Environmental Quality Act – indicate Napa can provide water to the development “under all single- and multi-year drought scenarios.”
Eldredge estimated the development, endowed with all of its planned residential and business areas, would require 300 acre-feet of water annually. That sum is less than 2 percent of the 15,200 acre-feet Napans typically consume in a non-drought year, she said. (The city has reported a 29 percent water-use reduction in July compared to the same month in 2013, as Napa and other towns comply with mandatory drought-related cutbacks the state imposed in April.)
One acre-foot of water, which equals 325,851 gallons, has long been a common benchmark for an average U.S. family’s water use for one year. But key aspects of Napa Pipe’s design should greatly reduce water requirements compared to the conventional suburban home with large, lush but thirsty lawns, according to city water officials.
“A lot of the homes, as proposed, are mixed use; the concept is work-loft (combinations) with retail downstairs,” she said Tuesday. “Higher-density development is much less water-intensive than standard single-family homes. Those 943 units sound like a lot, but they will use recycled water in shared common areas for their landscaping.”
Keith Rogal, the developer representing Napa Redevelopment Partners, described the 300 acre-foot annual water use figure as a conservative estimate that “is considerably more than we expect the project to require, given the relatively small housing units, the commitment to using recycled water (for irrigation) and the use of water-efficient fixtures.
“But we share Eldredge’s view that such forecasts should be made very, very conservatively,” he said in an email.
Though Napa Pipe’s projected water use per household is less than half of traditional levels, the efficiency gains made in irrigation, household fixtures and landscaping choices over the last 25 years make that goal reachable, according to Jay Lund, professor of civil and environmental engineering at UC Davis.
“It’s certainly attainable; if you go to some parts of the world they use less water still, but for California it’s doing pretty well,” he said, adding that per-family water use in many parts of California has gradually fallen to half an acre-foot per year.
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“The most important thing is avoiding the outdoor landscaping,” said Lund. “In the initial development, that’s your opportunity to find the easiest efficiency gains, in landscape irrigation.”
Councilwoman Juliana Inman said Napa Pipe’s design, and its reliance on reclaimed and not drinkable water for landscaping, should keep the project manageable for the city.
“It doesn’t have any large-lot development with lawns; this is like town houses and flats,” she said. “The residential component is limited to largely indoor water use, without the big outdoor water use you would have in single-family homes. It’s not like building a subdivision with 900 homes, because it’s a lower water demand.”
Other City Council members acknowledged the sensitivity of allowing a large new housing development in a time of record dryness, but said both Napa and the developer are equipped to preserve the city’s relatively ample supplies – at least in current conditions.
“I think we need to do a better job communicating with the public what our water situation is,” said Councilmember Mary Luros. “The water (supply) we have in Napa is pretty good as far as our reservoirs compared with the rest of the state.”
“One thing is that we don’t know exactly what this project will look like in the end. We really don’t know what’s going to happen, because it could be sold to other developers down the road. We know some things for sure. But at the end of the day, we can only do what we can.”
Councilman Scott Sedgley agreed that current city water stores could support Napa Pipe – but only if the California drought doesn’t extend too far into the future, a risk for the development given its planned build-out over many years.
“I detect a lot of concern (from Napans), and it’s a very valid concern,” he said Tuesday. “Will we, as a community, have enough water for the future if this drought continues? That’s the million-dollar question.”
“At what point do we declare a moratorium on all building? That question is always out there,” said Sedgley. “We hope the drought doesn’t last that long but if it does, that’s what we’d have to do as a council.”
Whatever Napa Pipe’s future, he added, one of its key elements – its emphasis on water-efficient plants and minimal lawn area – must become the new normal for local home construction.
“We are letting lawns go brown now (during the drought), but personally, I think we as a society in the West have to quit irrigating green lawns if they’re not used for recreational purposes,” said Sedgley. “The big front lawns are hopefully a thing of past. It’s just a luxury we can no longer afford even when we do get normal rainfall again.”