By Dan Walters, Sacramento Bee

The bad news is that a dry winter means the Sierra snowpack is only half of its statistical normal as the annual spring runoff begins.

The good news is that we’re still living off the unusually wet winter we had two years ago and major reservoirs – Shasta, Trinity, Oroville and Folsom – on the Sacramento River and its tributaries, plus the off-stream San Luis Reservoir, have very healthy leftover supplies, thereby cushioning the effects of the current shortfall.

Dan Walters

That’s what dams and reservoirs are supposed do, in case anyone has forgotten why water users and taxpayers spent billions of dollars to construct them decades ago.

California is not a desert, or at least most of it isn’t. In an average year, about 200 million acre-feet of water flow through the state. In a subpar year, flow might drop to 150 million acre-feet, but with total human use, including agriculture, only about 40 million acre-feet, the reservoirs allow us to even out the supply and keep water flowing to homes, fields and industry.

There are other benefits to reservoirs, such as flood control, fishing, water skiing and camping, but providing a dependable water supply for 38 million Californians is their primary purpose. Without them, 21st century life as we know it would be impossible.

Ironically, however, as those five big reservoirs, and dozens of smaller ones, do what they were designed to do – mitigate the negative effects of a dry winter – some Capitol politicians are talking about removing additional off-stream reservoirs from a controversial water bond issue.

The reservoirs were included to get Republican votes for the bond measure, but now that Democrats have two-thirds supermajorities in the Legislature, they don’t need GOP votes.

An election on that $11.1 billion bond issue has been postponed three times already because it’s loaded with pork, such as a quarter-billion-dollar handout to a power company owned by Warren Buffett and a park in the district of a former Assembly speaker, and politicians are worried that it would be rejected.

The pork should be removed and the bond issue reduced, as Gov. Jerry Brown wants.

However, two off-stream reservoirs to improve the reliability of California’s water supply are not pork, or at least shouldn’t be.

They shouldn’t be financed by taxpayers, as the current general obligation bond would do. They should be financed by water users, as dams and reservoirs have traditionally been financed. And if it makes more sense, surface storage reservoirs could be replaced with other forms of storage, such as underground.

However it’s done and however it’s financed, improving the reliability of California’s vital water supply through more storage makes sense now and will make even more sense if, as many believe, more of our precipitation falls as rain, rather than snow, due to global warming.