Dole Foods will fix three broken outlet valves on a water release system at Wahiawa’s Lake Wilson, providing greater control over water levels in the reservoir and added protection against flooding.
The repairs will allow Dole to better control the flow of water to its fields downstream, and to quickly release water from the lake to prevent a dam breach, which could send millions of gallons of water toward the North Shore.
"We are doing this to upgrade the system and to make the (water level) faster to lower," said Dan Nellis, Dole Food operations director.
The repairs will focus on valves that control flood gates near the Lake Wilson dam spillway. Once fixed, the three valves will allow dam operators to open and close the flood gates, sending water through a network of tunnels and into Kaukonahua Stream. Currently, only one of the valves—and the one gate that it controls—is operational, greatly slowing Dole’s ability to manage water levels in the lake.
"We are investing in what resources we can," Nellis said. "The system is safe, but we are upgrading it to make it safer."
According to Nellis, Dole is in the final stages of securing a contractor for the project.
At the June Wahiawa-Whitmore Village Neighborhood Board meeting, Dole reported that the repairs will cost an estimated $1 million and take a minimum of six months to complete. Nellis said the project could be delayed for up to four months if complications with the aging flood gates arise.
Howard Green, a Honolulu attorney who owns half of the lake and leases his property to Dole, said he has been urging Dole to fix the water release system since late 2008. Although he said the approval process for the repairs has taken longer than expected, he is grateful to see the project beginning to take shape.
"The process of getting Dole to do this has been slower than I wish it were," Green said.
The Wahiawa-Whitmore Village Neighborhood Board has also been supportive of the valve repairs.
"It’s a flood control issue," said board co-chairman Joseph Francher. "This has been sitting out there for years, and nobody wanted to spend the money to get it repaired."
The valve repairs follow a $1.5 million overhaul of the outlet tunnels in the dam, which Dole completed last year. According to Nellis, Dole upgraded the tunnels in preparation for the valve repairs.
"We overhauled the outlet tunnel to prepare, and now we go in and do the valves," Nellis said. "The intention all along was to reduce the volume faster."
In addition to improving Dole’s reaction time in heavy downpours, the valve repairs will allow lake owners to prevent flooding by reducing reservoir levels even before the rain starts to fall. In March 2009, Dole drained water in the reservoir to 65 fee to reduce pressure on the embankments and provide added capacity for rain water.
Nellis hopes the repairs will prevent close calls like a December 2008 rainstorm that increased water levels to within eight feet of the top of the dam.
"The ability to drain the reservoir means we are able to protect the dam from the potential of over-topping … which could ultimately destroy the dam and cause a much larger flood in the Waialua area," he said. "It needs to get done."