In other presentations:

• David Zoldoske, director of the Center for Irrigation Technology, took issue with a Pacific Institute report that between 4.5 and 6 million acre feet of water could be saved in irrigated agriculture.

He and other researchers released a report stating water conservation alone would not free up large amounts of water for other uses. He said the study did not take into account that water is reused if there is deep irrigation or runoff: “The water goes someplace.”

Groundwater overdraft of about 2 million acre feet per year continues to be a problem, Zoldoske said. “Instead of the groundwater rising, the opposite is happening,” he said.

Switching from flood irrigation to drip reroutes water within a region but does not create new water outside the basin, Zoldoske said.

• Tim Quinn, executive director of the Association of California Water Agencies, said the concept of “coequal goals” for water use is costly as efforts are made to improve water supplies while restoring ecosystems.

Despite shunning of surface water storage, he said, there have been success stories in the past 15 years as new water supplies totaling 2 million acre feet — more than the current yield of the State Water Project — have been created. He said some $6 billion has been spent, mostly by local agencies.

• Eduardo Currea, sales manager for the U.S. and Mexico with Rain Bird, talked of the use of water for overhead frost protection in vineyards.

Currea said ice encasement serves as a heat source. He said it is important to determine the capacity of water needed. Running out of water and ceasing application early can compound problems, he said. And starting the systems too late can also be a problem.

Currea said it is vital that sprinkling systems be aligned so that water is falling on the vines. He said it may be necessary to have workers in raincoats check on that alignment.

• Andy Smith, an accounts manager with Reinke Mechanized Irrigation Systems in Boyne, City, Mich., talked of mechanized irrigation with pivots and diversity they offer.

He said systems can deliver water above the canopy, in the canopy and at ground level. He said they can be used for chemigation and fertigation and for “regenerative water use,” for example applying “dirty water” from dairies to forage crops.

For municipalities, they can be used to apply treated effluent.

“But it’s not ‘set it and forget it,’” he said, citing an example of the need to clean pig hair out of a filter.