Irvine Lake begins mass draining project for upgrades to 93-year-old reservoir

Irvine Lake began draining this morning ahead of the El Niño and to upgrade the 93-year-old reservoir.

Aside from making room for the upcoming El Niño, the water draining is part of the Irvine Ranch Water District's $470 million Santiago Creek Dam improvement, which provides drinking and irrigation water to 1.5 million residents in Orange County. 

"We need to replace the outlet tower and the spillway completely," said John Fabris, a spokesperson for Irvine Ranch Water District. "We're going to bring it up to state-of-the-art in terms of seismic safety."

Wendy Tochihara likes to fish in the lake and wonders where the fish will go.

"We want to save that fishery. It's huge," she said. "I want a full fishery assessment of that lake."

She said that the trophy-class fishery is home to massive catfish, trout, sturgeon, wipers and bluegill.

"These bass that were put in that lake are called F1 largemouth bass," Tochihara said. "Those are the purest form of Florida strain largemouth. You can't get them."

Right now, the fish have a home that's around 23 feet deep. In three weeks, it's expected to go down to five feet. Once the contractors are prepared to work on the dam, that's when crews will drain it completely. 

The California Department of Fish and Wildlife said they can't enforce anything since the fish are non-native species that live in a private lake. They suggested residents contact Irvine Ranch Water District or Orange County Parks to temporarily relocate the fish or host a fishing derby. 

Fabris said their goal is to restock the lake when the project is done in the summer of 2032. Tochihara said it won't be the same. 

"If all those fish are dead and they stock the lake with smaller fish, it's no longer a trophy-class fishery," she said. "Are the people going to come back?"