It’s apparently legal for California’s water districts to raise property taxes without a public vote to pay for the proposed $25 billion Delta twin-tunnel project, but that doesn’t make it right.

As crazy as it sounds, the Santa Clara Valley Water District and others in the state can move the massive project forward this fall without the approval of California voters or the Legislature for either the tunnels themselves or for property tax increases to pay for them.

It’s just wrong. The local water board should reject the idea out of hand. If it wants to raise taxes for this, it should at least ask voters for permission.

At a minimum, the Santa Clara Valley District will be on the hook for a whopping $225 million from property owners and ratepayers if the tunnels move forward. But Northern Californians have little or nothing to gain from the project, which will further drain the fragile Delta so that Central Valley farmers can keep growing thirsty crops in what amounts to a desert.

Other Bay Area districts understand this. The Contra Costa Water District, East Bay Municipal Utility District and the San Francisco Public Utilities Commission are not planning to participate in the twin tunnel funding.

The Santa Clara district’s staff argues the project will result in a more reliable water supply. But for that, the tunnels — the largest state water project in history — are the very definition of overkill: Each would be bigger than the Chunnel between England and France, even though state officials know they will produce no more water than what’s pumped today. Building two tunnels in case one fails is insane.

The local district’s 1.8 million customers could be on the hook for an even larger share of the cost if some of the other 20 participating water districts pull out of the project. The San Diego County Water Authority, which is part of the giant Los Angeles-based Metropolitan Water District, is raising serious red flags about the project.

What’s needed to ensure stability is restoring the Delta’s health. Repairing levees and increasing the flow of water through the estuary rather than diverting more of it could be done at a fraction of the tunnels’ cost. These are the kinds of projects the governor and Legislature should include in the water bond they’ll debate Monday to possibly place on the November ballot.

Assuming we eventually get rain — and if we don’t, there’ll be nothing to send through the tunnels — the answer to more reliable water supplies is expanding the capacity of reservoirs, restoring overpumped groundwater and scaling up recycling and conservation, including requiring plumbing for reuse of gray water.

If a new conveyance system is necessary, a smaller, single tunnel proposed by a coalition of environmental and business groups would be cheaper and do far less environmental damage.

These are the ideas the Santa Clara Valley Water District board should be exploring, not raising taxes without a public vote to pay for the state’s tunnel vision.