Just like 25 years ago, California’s top politicians and special interests are lining up behind the idea of a canal that would suck in pristine Sacramento River water, send it flowing through or around the Delta and pump it south to thirsty users.

Perhaps, like then, it will take a collection of oddball but fervent opponents to halt it. Only this time, some of the canal supporters are swaying one-time opponents in Contra Costa County and the south Delta to join them by offering a through-Delta canal with buttressed levees and a permanent gate at Five Points at the head of Old River, respectively.

The levees along the south fork of the Mokelumne River and Middle River would protect the fresh water, fisheries and island farmland from saltwater intrusion. Plus, that plan would keep Southern California and Bay Area water users from taking water above the Delta and from threatening Contra Costa County’s water supply.

With the barrier, Middle River in the south Delta would be cut off from the effects of water drawn into the state and federal pumping plants, allowing it to return to a more natural ecological state to the benefit of farming and fisheries.

Oh, happy days? No quite. The so-called through-Delta conveyance is just one of several options that are being formulated. It’s been on the table since 2000 when first proposed by the infamous Cal-Fed, state-federal, Bay-Delta water consortium that died after Congress eventually refused to fully fund it.

However, the through-Delta plan might be the best alternative, and the only hope to protect Delta interests, even if it tastes like castor oil. The other two options: a peripheral canal or a dual peripheral canal and through-Delta canal are potential landmines to the economic, environmental and recreational stability of the Delta.

Gov. Arnold Schwarzenegger’s proposed $9 billion water infrastructure bond doesn’t contain money for water conveyance. However, $2.5 billion of Schwarzenegger’s proposed water bond would be promised for Delta restoration and improving fish habitat contingent on the acceptance of a canal.

The governor’s office and the Association of California Water Agencies already are campaigning heavily for the hearts and minds of Californians on the canal issue. Schwarzenegger’s assistants are countering the myths of the plan to send Sacramento River water around, instead of through, the Delta, so it can be pumped south. Southern California water agencies are warning Californians that they will be parched unless there are major modifications with the water strategy.

That is enough for opponents of any canal to remain sentinels of any political con job. Before anyone at the state Capitol or elsewhere takes Schwarzenegger’s water storage and Delta restoration bond proposal seriously, let’s wait until December when a state blue-ribbon task force, which has been carefully weighing the Delta options, is to recommend a solution to California’s water crisis.

Then, the campaigning can begin.