The thundering of water gushing over Canyon Lake's dam Thursday was music to the ears of those who oversee that lake as well as Lake Elsinore.

"It's a beautiful cascade," said Lake Elsinore Aquatics Resource Director Pat Kilroy. "It's probably 6 inches above the actual spillway, so it's going pretty good."

For the city as well as the Elsinore Valley Municipal Water District, it's raining money. When Canyon Lake's level reaches 1,382 feet, the point at which it begins to overflow the dam, that means the district can ramp up its treatment plant full blast to convert the lake water to drinking water.

"We've been running our water treatment plant up there to use that water instead of paying for real, expensive imported water," district spokesman Greg Morrison said. "We're running our plant at 7 million gallons per day."

Before the series of storms started recently, the district had been extracting about 5 million gallons per day because of its low level. The lake was nearing the point where the district would have to stop drawing on it to honor an agreement with the Canyon Lake Property Owners Association to keep it at a minimum of 1,372 feet above sea level, Morrison said.

Lake Elsinore benefits because the water spilling over the dam flows down the San Jacinto River channel into the lake. That, combined with the rainfall and runoff that goes directly into Lake Elsinore, reduces the amount of money the city and water district would have to spend to keep the lake from drying up.

Also, the infusion of water keeps the lake healthy and attractive to anglers and boaters, adding money to the coffers of the city and surrounding businesses.

"It's just Mother Nature helping out what the city and water district have been doing to stabilize the lake levels," Morrison said.

The lake evaporates at a rate of about 4 1/2 feet per year, and a lack of a decent amount of rain in the last couple of years led the lake to fall below the 1,240 elevation level last fall for the first time since 2005.

The 1,240-foot elevation, which gives the lake a maximum depth of 22 feet, is considered the lowest level at which the lake functions in optimal health and below which it begins to deteriorate. Below 1,240 also means the city must shut down its launch ramp on the lake's northeast side to boats, other than small craft such as jet-skis and kayaks.

The rain this week had brought the lake back a few inches above 1,240 feet by midweek, and officials expect the lake to gain up to a foot per day for several days.

"By the end of this, we'll probably be at about 1,244 or 1,245 ---- that's very good news," said City Councilman Thomas Buckley, who can see the lake from his home. "We're supposed to have another rain storm, so I think we'll get a couple of years ahead on the evaporation."

Call staff writer Michael J. Williams at 951-676-4315, ext. 2635.