The lengthy plan to reverse decades of decline in the Delta while also serving the water needs of millions includes much more than just 45 mile long proposed underground tunnel system from Clarksburg to south of Discovery Bay... and yet those tunnels overshadow the entire discussion.
After all, the water tunnels are the mechanism by which supporters can claim the plan will work. And yet, that plan won't answer one of the biggest questions: how much water will the tunnels transport from north to south?
"This plan does not include any guarantees for water supply deliveries," said Mark Cowin, director of the state Department of Water Resources, at the Thursday unveiling of the first portion of the long awaited Bay Delta Conservation Plan (BDCP).
The draft plan will be released in two more spurts through the end of April and is the work product of some seven years of research and discussions by water agencies, scientists, activists, and beyond and the core of a 2009 state law that mandates "co-equal" goals of a reliable water supply and Delta ecosystem protection.
Which gets us back to the question about how much water the BDCP will allow to be transported to the south.
The tunnels were downsized from earlier plans when unveiled by Gov. Jerry Brown last July, and are now designed to carry a maximum of 9,000 cubic feet a second to pumps located at the south end of the Delta region.
For those who don't measure water in cubic feet, that's 67, 320 gallons a second.
But state officials say that's simply the maximum, not the target. They say the BDCP will only allow as much water to be taken out of the river -- through intake stations between Clarksburg and Courtland -- as the plan's species protection rules will allow.
"We're not talking about one species, we're talking about how to better manage 57 species," said Chuck Bonham, director of the California Department of Fish and Wildlife.
The first draft BDCP chapters released on Thursday include 22 separate conservation measures and envisions a 50-year time period for protection of fish and animal species in an area encompassing some 60,000 acres.
Still, there's that not-so-certain threshold of water that will be diverted by the tunnels of the Sacramento River.
State water director Cowin said the goal is a range slightly above and below the 20 year average of water usage, which he pegged at about 5.3 million acre feet a year.
(Translation: that average is about 1.73 trillion gallons.)
The proposal has done little to dissuade critics from calling the project a boondoggle.
"The Bay Delta Conservation Plan continues to rely on an unrealistic, grossly expensive proposal that fails to meet the state's own objectives in the Delta," said state Sen. Lois Wolk, D-Davis.
She and other critics argue that the plans reliance on underground tunnels is a major flaw. And much of the criticism falls squarely on Gov. Jerry Brown, whose 1982 effort to build a peripheral canal was soundly rejected by voters.
"The governor wants the tunnels," said Bob Wright, of the activist group Friends of the River. "They're not looking at any alternatives."
The alternative some Delta regional groups want is a much smaller tunnel -- one two thirds smaller than the current Brown administration proposal.
And they have even have some support even in Southern California, as local agencies may want more certainty about how much certainty about how much water they'd be getting before ponying up as much as $14 billion to construct the twin underground tunnels.
"We hope this draft and future revised drafts analyze a full-range of alternatives," said San Diego County Water Authority general manager Maureen Stapleton in a written statement about the new BDCP proposal.
And, as has so often been the case in the past, there's always the threat of lawsuits.
As one participant in Thursday's release of the draft proposal, a federal lawsuit from more than a decade ago may have said it best: "Water litigation is a weed that flowers in the arid West."