Jerry Brown, preoccupied with campaigns for other offices, only occasionally engaged in governing California during his first stint as its chief executive 30-plus years ago.

One of the few issues that he did pursue was a "peripheral canal" to carry Sacramento River water around the Sacramento-San Joaquin Delta to the California Aqueduct near Tracy, and thence southward.

The canal would complete the water plan that Brown's father had begun two decades earlier and, he contended, arrest the Delta's environmental deterioration from sucking its water into the aqueduct.

That assessment was justified, but initial support from some environmental groups turned sour; they worried that new plumbing would remove physical barriers to massive increases in water shipments.

Ironically, however, big farming interests – particularly the Boswell and Salyer empires – also opposed Brown's plan because, they feared, it would generate too little water. At the time, they were facing severe cutbacks in federal water by the Jimmy Carter administration.

The odd-bedfellows alliance of environmentalists and farmers forced Brown into old-fashioned political horse trading – such as promising public works projects to fence-sitting legislators – to win approval.

However, his victory in the Capitol was short-lived as opponents gathered signatures for a 1982 referendum to overturn his plan. The campaign for the canal was inept, its opponents were well-financed and the canal was rejected by voters just months before Brown's governorship ended.

Exactly 30 years later, Brown is back in the governorship and reviving the peripheral canal, only it's morphed into a pair of 33-foot-wide tunnels.

Brown and the Obama administration will declare agreement on moving forward on the Delta tunnel project this week.

So what's changed?

The Delta has deteriorated even more, judges have restricted pumping to protect it, farmers complain of shortages, and with a 50-plus percent growth in population, Southern Californians are worried about water supply reliability.

Environmentalists remain largely opposed for the same reasons – a fear that better plumbing could increase water shipments southward and, incidentally, remove water supply as their biggest tool in fighting urban land development. But their old allies in the farming community are now vigorously supporting the tunnels.

Water users, not taxpayers, would pay for the project. But the restoration of the Delta's habitat, a key element of the overall plan, would depend largely on a bond issue that's been withdrawn from the 2012 ballot and will be rewritten. So that's a potentially weak political link.

Will it happen?

It should, but it's no more certain than Brown's other legacy project, a bullet train system.

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