Where is it written in the “Book of California” that coastal cities that are addicted to Sierra snowpack runoff from outside of their water basins can play the “pristine environmental trump card” to try and kill a desalination plant using ocean water?

There is indeed a morality debate going on in Huntington Beach over whether to allow the proposed Poseidon desalination to be built. The Surf City USA folks in Orange County are locking horns over protecting the coastal environmental near the proposed plant and the need to have another water source to buffer against droughts.

But the real environmental damage isn’t what will happen in close proximity to where the seawater is sucked into the plant, separates elements that make water non-drinkable and then return those elements to the ocean.

It’s what Huntington Beach’s demand for water — as well as that of the rest of the Los Angeles Basin including Orange County — is and will do to damage a much more threatened ecological system some 360 miles to the north.

That is where the mother of all water districts — the Metropolitan Water District of Southern California (MWD) — is pushing forward to make sure their cup doesn’t run dry without a peep from anyone in Surf City USA  debating the plan to devastate areas tens of thousands time larger than the desalinization plant .

The MWD wants a tunnel bypassing the Delta to assure the stability of their water supplies during droughts although they use the smoke screen of saying their main concern is a massive earthquake that might collapse Delta levees.

By diverting water south of Sacramento that the MWD takes from the Sierra snowmelt and sending into a tunnel under the Delta and then dumping it directly into the California Aqueduct, it will deprive the already hammered Delta ecological system of the benefit of water that would have flowed through it .

The loss of water to evaporation via surface flows through the Delta is minimal. But the loss of water to fish and vegetation given how less and less water would seriously alter water temperatures, reduced oxygen levels and impact the food chain among others has the potential to be catastrophic.

The MWD supplies water to numerous cities in the Los Angeles Basin including Huntington Beach as well as the San Diego area.

Huntington Beach uses primarily well water but it still sucks water out of the ecological systems in Northern California via the MWD.

To its credit, Huntington Beach is part of the Orange County Water District that takes treated wastewater and infuses it with surface water to replenish aquifers.

The issue isn’t whether a city in the Golden State uses — and reuses — water wisely, but making sure the step taken going forward to weather the growing water crisis have a minimal impact on the overall California ecological system.

Given the MWD — and by extension Huntington Beach — already are monkeying with the Delta ecological system, they must weigh whether the desalinization plant in their own backyard or the continued importation of water that now flows through the Delta is higher on the ecological Richter Scale.

Cities within the water basins that feed the Delta are already doing their part.

Manteca treats wastewater that originates from ground and surface sources and returns it to the San Joaquin River to flow into the Delta.

Turlock is preparing to switch to a treatment system where the water they use will be repurposed for agricultural uses. As such it will take pressure off of natural water flows to the Delta that are tapped to help grow food that helps feed people in Modesto as well as Huntington Beach.

The pressure on waster in the San Joaquin River and Sacramento River basins that flow into the Delta is not abating. It will get worse whether you attribute it to megadrought cycles that have existed for centuries, modern climate change science, or growth.

It is clear desalinization plants in Southern California  — an arid region that long ago exceeded its ability to support itself from water originating in its own basin — will provide a more stable water supply at overall significantly less damage to the overall California environmental balance sheet.

Auxiliary arguments about a desalinization plant being a tourism killer in Huntington Beach can’t be weighed in a vacuum. Continued use of water originating in Northern California during drought conditions will have devastating impacts on tourism in not just the Delta but near north state reservoirs.

Should a well-to-do community siphoning water to sustain itself — and even grow — from another water basin be able to protect their tourism economy at the expense of tourism economies in less affluent parts of California?

Desalinization plants around the world have helped cities proposer in areas that lack adequate surface water supplies.

New technologies plus the rising cost of water that is either stored behind dams or pumped from aquifers getting higher in price with each passing month when non-contracted water is sold is  helping such plants pencil out even in places like California’s where water — despite how scarce the commodity can be at times —is cheap.

San Diego — where Poseidon has built a similar plant — is now getting 10 percent of its water supply from desalination.

The Orange County Water District that serves 2.5 million people including Huntington Beach wants to buy water from the plant Poseidon is proposing in Surf City USA.

The NIMBYism of the opposition is off the scale.

It is OK to continue to further devastate natural waterways hundreds of miles away to help sustain Huntington Beach and nearby communities but don’t you dare touch the Pacific Ocean in their own front yard.

California will weather the challenges of not enough water through compromise and actions that take the entire state into account and not simply sell one region substantially short to allow another region to keep growing and prospering.

And in terms of balancing the scales when it comes to water, the Poseidon plant in Huntington Beach will barely be a drip in the overall scheme of how the Los Angeles Basin is drinking, bathing, filling swimming pools, irrigating lawns, and such way beyond the means of their water basin.

This column is the opinion of editor, Dennis Wyatt, and does not necessarily represent the opinions of The Bulletin or 209 Multimedia. He can be reached at dwyatt@mantecabulletin.com