Issue link: http://winesandvines.uberflip.com/i/629061
18 WINES&VINES February 2016 WINE INDUSTRY NEWS green. "We can drive along the highway and look at vineyards with micro-drip systems, which put the water right on the roots, and think how efficient that is. They've been doing it for a generation, and that's one reason we have groundwater problems now." If micro-drip or other irrigation systems are in fact depleting groundwater levels, what is left for agriculture in a historically dry state? "What we are doing over the next few years is to try flooding fields during winter wet sys- tems," Sumner said. "We have people on cam- pus measuring how much winter flooding will benefit almonds, alfalfa and vines." Deep flood- ing during winter storms would, they believe, recharge groundwater supplies. The mental image of deliberately flooded vineyards is perhaps disconcerting, but it's not new technology. Nat DiBuduo, long-time presi- dent of Allied Grape Growers, a marketing cooperative serving some 600 grower-members in California, recalled his father flooding his fields in the mid-20th century. "The vast majority of vineyards are irri- gated. Most comes from groundwater or res- ervoirs," he said. "In the San Joaquin Valley, it's predominantly groundwater." A little bit of seasonal rain will not replenish the supply. "It's taken centuries to build." Flooding provides two things, DiBuduo said. "It puts water down, and the excess goes into ground" instead of running off into bays and estuaries. In soils that are excessively salty, the moisture goes below the vine root zones. "When you flood, the root zone is out of the middle of rows. It's old-style farming. Pumping too much groundwater creates another problem, he said. "Imagine an inflated water balloon between two layers of dirt. If you suck that water out, you can't blow the balloon back up. We've got to come up with solutions. Farming's been around for a long time, and farmers are optimists. We're all survivors." Dr. Lowell Zelinski, a viticulture consultant and vice president of the Independent Grape Growers of Paso Robles Association, agreed. "Rainfalll here is OK but not great. It's better than it has been, but not sufficient to affect groundwater. Typically our rain comes in the spring, so we're still optimistic." Paso faces a political dilemma this year. A proposal to establish a new water district will come before voters March 8. The proposal asks landowners and registered voters if they want a district; funding is another question. "I'd like to see the district formed," Zelinski said. He thinks the district is likely but voters won't pass funding for one. An emergency mora- torium on new groundwater extraction in San Luis Obispo County was enacted by the Board of Supervisors, but "that lasted about two hours," he said. "If you have an acre or 20 acres without a well, it's now just rangeland." —Jane Firstenfeld Water runoff pools next to a vineyard in the Oak Knoll District of Napa Valley.