Fisherman Stan Wright said he is afraid a continuing loss of water at Lake Wilson could cause a massive die-off of fish at one of the best angling places he knows in the United States.

"That’s my biggest concern," said Wright, a recurring guest and one-time host on the Hawaii TV program "Let’s Go Fishing."

Wright said in some parts of the lake normally 75 feet deep, the depth has dropped to 35 feet.

Tree roots and dumped shopping carts are visible along some areas of the exposed bank.

Dole Foods Co. Hawaii, the operator of Lake Wilson, said it is in the process of fixing an outlet valve that has been draining the water.

"We’ve been working on the problem for the last week and a half," said Daniel Nellis, operations director. "We’ve identified the problem. We’ve got engineers working on it."

Nellis said the drained water has been irrigating Dole fields and some water may be emptying into Kaukonahua Stream.

He said none of the Dole crops has been harmed by the valve malfunction.

Nellis said he doesn’t know the exact cause of the malfunction but suspects it may be metal fatigue.

"This is the kind of thing that can happen with valves … something has given way, so it won’t close," he said.

The company has not said how long it will take for the problem to be fixed.

Lake Wilson is the largest fresh water reservoir in the state with a capacity of 3 billion gallons and a meandering shoreline of 20 miles.

The source of the water is the watershed in the west Koolau mountains.

State officials who operate a fishing area in Lake Wilson said they are monitoring the situation.

"We’re concerned about the health of the fish in the lake, if the water level drops much further," said Deborah Ward, spokeswoman for the Department of Land and Natural Resources.

If the lake continues to drain and a die-off seems near, state conservation officials have a plan to put temporary pumps into the lake to circulate the water and provide oxygen for the fish.

Last July, Dole announced it was fixing three broken outlet valves to provide greater control over water levels in the reservoir and added protection against flooding.

Nellis said Dole began repairing some outlet valves last year and will continue the work once the broken valve is fixed.

He said once the valve is fixed, he hopes rain will refill the reservoir.

Wright said a variety of freshwater fish, including peacock bass and largemouth bass, inhabit the waters, and the fishing is good.

"I would put it against any mainland lake," he said.