Hard to Fathom : Recreation: It has its own beach, underwater tunnel and island. Do not even ask the Santa Clarita couple about how much it will cost to heat the back-yard ‘monsterpiece.’

Moses parted the Red Sea, but he might be daunted by the size of Linda and Steve Erenberg’s back-yard swimming pool.

It is, in a word, massive.

Whereas it takes about 13,000 gallons of water to fill the average swimming pool, the Erenbergs’ new pool will consume a projected 140,000 gallons.

And don’t even ask about a heating bill. If a normal pool is warmed by a 400,000 BTU heater, the Erenbergs pond will take a million BTUs.

Add to all this an 18-foot waterfall, one underwater tunnel, a beach, an island, four bridges and a swim-up bar. Then throw in a 20-person spa and sunken conversation pit, topped by a 15-foot tiled water slide that empties into a 12-foot-deep diving hole.

The only thing missing is a champagne-spouting volcano.

The pool takes up about 4,000-square-feet of the Erenbergs’ 1 1/2-acre home site in Santa Clarita. Their 3,800-square-foot, four-bedroom ranch-style home uses up much of the rest.

The couple has one child, an 18-year-old daughter, April, who is away at college.

So what are they planning to do with a pool the size of Las Vegas?

“That’s a good question,” says Erenberg, who is owner of SCV Pools, Spas and Masonry in Santa Clarita.

His answer is that he did not mean to build the pool that consumed Santa Clarita; the project just sort of took on a life of its own.

“Four years ago, when Linda, April and I moved in here, we looked at the back yard and said we could really build something nice out there,” he said.

So he started out modestly, laying out the pool of his dreams with spray paint on the area on which he would build his aquatic masterpiece.

So far, so good.

But over time, he would look out the window and realize that he had forgotten something and would add it to the pool and area. Three years and $350,000 later, the pool is nearing completion. It should be ready to be filled with water by Halloween.

Erenberg, 41, said he knows of only one other private pool of this size in Los Angeles County, but he is quick to add that it does not have everything that his pool has. Certainly not its own private beach.

He admits that there were times during the drought when he had concerns about using the water. Then last winter the skies opened and flooded the area.

“The pool actually filled up by itself before we had finished it. We got a Jet Ski and sort of tooled around in it,” he said.

A Jet Ski in the swimming pool did not thrill his neighbors. Neither have all the truck traffic and noise resulting from the construction.

“Well, it’s an affluent community where people don’t like that sort of thing,” said next-door neighbor John McVay.

McVay said construction created a certain amount of chaos for neighbors, and that some are less than amused by the big trucks rumbling in and out. But McVay added that “now that the project is nearing completion, the animosity should die down.”

“People think we have totally lost it,” said Linda Erenberg, 39, who works as her husband’s partner in the pool construction business. “I admit I have had doubts when I realized how much the project had sort of grown into a monsterpiece . . . (but) this is our business, and we wanted our pool to be a showplace.”

She said she had no idea and does not want to think about how much it will cost to fill the pool with water, or what her monthly electricity and water bill might be.

She does know that the $350,000 pool has boosted what she would ask for the house to $950,000, should she want to sell it, which she has no intention of doing.

Steve Erenberg is unrepentant about what some might call the worst sort of conspicuous consumption. He looks at the pool as a labor of love, as well as a way to share what he does well with those in the community.

“We have not only planned a number of parties for our friends and neighbors, we will be donating our recreation area to various charities who want to hold benefits out there,” he said.

He said the Henry Mayo Hospital Guild has booked a fund-raising party there, and added that he expects to be as generous as possible with other community groups.