GEYSERVILLE — Winegrape growers that depend on water in the Russian River Basin to protect their vines from frost assert they have a better idea of how much water they’re using and how to limit such use, while wildlife regulators say they’re getting more precise information of water overuse and tools to curtail it. That’s what a capacity gathering of 168 vineyard and winery professionals braved an Alexander Valley downpour to hear at a Feb. 26 workshop on the nascent Russian River Frost Program. That program was presented to the State Water Resources Control Board in November as way to cooperatively manage water use similar to Napa Valley’s three-decade-old regime.