California's Diamond Lake Opens

USSFN:  10/14/03 - On Friday, Oct. 3, the Metropolitan Water District of Southern California, in partnership with the California Department of Fish and Game (DFG), opened one of the best and most diverse fisheries at Diamond Valley Lake near Hemet in southwest Riverside County.  Measuring 4½ miles long and two miles wide, the lake promises to be an angler's paradise, state fishery experts predict.

"Like many others throughout the region - actually we've had calls from across the country and from as far away as Japan - I've really been looking forward to getting out on the lake and landing some of the big bass that have been growing for the past five years," said Jill T. Wicke, Metropolitan's manager of water system operations.

The Metropolitan Water District of Southern California is a cooperative of 26 cities and water agencies serving 18 million people in six counties. The district imports water from the Colorado River and Northern California to supplement local supplies, and helps its members to develop increased water conservation, recycling, storage and other water-management programs.

"Because this is a drinking water reservoir and emergency supply for about 18 million people, Metropolitan's number one priority is the safety and reliability of the lake's water. After those concerns are assured, you're going to find me and my family out on the lake," said Wicke, an avid angler.

Because of the extensive fishery planning involved at Diamond Valley, Mike Guisti, the lead DFG biologist at the lake, calls the outcome a true Department success story. In collaboration with Metropolitan since 1997, DFG managed the lake's fishery since 1999.

"Keep in mind, this lake is just three years old," Giusti said. "For its age, it's the best fishery in Southern California. And, if the growth rates continue, in five years there won't be another lake that can touch it."

Before the water district began filling the 260-billion-gallon reservoir in early 2000, DFG biologists invited anglers from across the state to provide input on how they would like the fishery to be managed.

"The fishery was developed with a lot of help from the public. It wasn't just any one person's plan, or strictly a Fish and Game plan," said Giusti. "We had people who asked us about bringing in several different types of fish, and building underwater reefs."

The Department responded by establishing nearly a dozen different fisheries and constructing a series of pipe caves and brush structures, as well as hundreds of rock reefs that form underwater havens for the fish.

Even before the lake's opening day, DFG officials sensed Diamond Valley's potential for becoming one of the Department's premier successes, as one of the of the most respectable fisheries in the West.

"We have the potential for a 20-pound plus bass to be caught here, but I think that is still five to 10 years away," Giusti said. "I think the genetics are in our favor, as well as the growth rates we are seeing. And, there's a ton of food in there."

Diamond Valley's bass fishery planning began in 1997 when eight lakes were sampled for bass. Those waters included Upper Otay, Miramar, Castaic, Casitas, Pyramid, Perris and Lake Hodges. The goal was to retrieve samples of bass and send them to the University of California at Davis to determine which were the purest of the bunch.

With about 96 percent pure largemouth bass genes, Lake Hodges proved to offer the best genetic material. As a result, in February 1999, DFG relocated 217 Hodges bass to an 80-acre pond constructed on the floor of Diamond Valley. The bass averaged 2 to 4 pounds, with a half-dozen between 5 and 8 pounds, and one more than 8 pounds.

The lake's structure has proven to be conducive to a successful, diverse bass fishery. Prior to the filling, a structure was placed between 35 to 120 feet down when the lake is at full pool. Lake levels are expected to fluctuate annually about 35 feet.

Although no largemouth bass were planted since the original stocking, preliminary estimates taken in the spring show there are 35,000 largemouth bass greater than 12 inches in the lake. Of those fish, the average size is 2 to 4 pounds.

"The reservoir is maintaining amazing growth rates," Giusti admitted. "In their first year, bass are rreaching 12 inches and are putting on a pound per year thereafter."

Meanwhile, smallmouth bass were taken from Shaver Lake in Central California to help the mountain lake recover from a stunted bass population. Some 1,700 smallmouth bass averaging 7 inches were placed into the Diamond Valley rearing pond. Each year since 2000, DFG has added 500 smallmouth to the lake.

"The vegetation below the lake's surface helps promote bass growth," Giusti said. "When the lake filled, it flooded the vegetation along the reservoir's floor and slopes, making great habitat. hat habitat should last for another five years."

Most of the fish growth at the lake stems from a well-balanced food source. DFG introduced two strains of crawdads - both red swamp and signals - silverside minnows and panfish, as well as tule perch, carp, shad and freshwater shrimp that came in with the imported water.

"The silversides are the primary reason the bass are so big. When I cruised the shoreline when he lake was lower, it was like a river of fish and all of them were silversides. They are great bass food," Giusti said.

Bass are not the only species on the fishery menu. Channel and blue catfish also are available, yet may be difficult to target for many anglers because no night fishing will be permitted. Some 100 3- to 5-pound channel catfish were relocated from Metropolitan's nearby Lake Mathews, as well as 200 blue catfish from 5 to 25 pounds.

"Diamond Valley is a pretty steep reservoir and catfish like gently sloping reservoirs, so we'll have to see how things go," Giusti said. "However, it's possible that a catfish more than 100 pounds could be in the lake some day, but that could take 20 years. Eventually, I could see a big blue catfish grow about 5 pounds a year. But right now, I bet the bigger blues that were put n are about 30 pounds."

Bluegill and redear sunfish also are part of the fishery mix. In cooperation with the Arizona Game and Fish Department, DFG transferred 400 redears from the Colorado River, with Arizona contributing another 100,000. About 3,000 bluegills came from Lake Perris and 20,000 were purchased from private hatcheries in Central California. "The lake should support decent panfish fishery," Giusti said.

In addition, Diamond Valley offers the most successful two-tier fishery in the region. The cold-water fishery may be the most successful put-and-grow fishery in the state, Giusti said, offering several strains of trout including Hot Creek, Eagle Lake, Coleman and Whitney.

"I think this lake is going to offer a fishery we haven't had before in Southern California," he said. "There's no doubt that the quality of trout is here. In fact, the growth rates exceed what we could do in a hatchery. Since 1999, we've stocked more than 200,000 trout. I could easily see 20-pound limits of five fish when the lake opens. Right now, there isn't a trout in the lake under 2 pounds. They should be averaging 2 to 5 pounds. We should see a lot of fish in the 7-to10-pound range."

General statewide fishing regulations will govern the reservoir. Creel limits are as follows: five bass 12 inches or larger, regardless of species; five trout and only five in possession; no limit on panfish; and 10 catfish.

For more information on Diamond Valley Lake and the fishery, visit Metropolitan's Web site at www.mwdh20.com.

Contacts: Bob Muir, Metropolitan Water District, (213) 217-6930; Troy Swauger, Department of Fish and Game, (916) 654-2096