Dillon Reservoir waters Denver during Cheesman project
Ryan Summerlin October 4, 2010
SUMMIT COUNTY – With Denver Water drawing more heavily from Dillon Reservoir, levels are down about 8 feet and are slated to drop 3-4 inches daily until Dec. 1, Frisco Bay Marina marina manager Phil Hofer said.
As of Monday, the reservoir was about 4 feet lower than normal for October, Denver Water spokeswoman Stacy Chesney said.
She said three factors contribute to the lowering water levels: Denver needs more water because of an unusually hot and dry September; the high country weather has not produced usual inflow levels; and a rehabilitation project at Cheesman Reservoir requires water levels to remain high and steady.
It has caused more boaters than usual to pull their vessels out of the water early, Hofer said. Others have moved their boats to a mooring in deeper water, and use a dinghy or marina shuttle for access. In recent years, boats have been able to remain on slips until closing day.
“It has inconvenienced boaters who want to boat as long as they can,” Hofer said, adding that the marina’s shorter fall hours mean boaters who rely on shuttle service must come in earlier.
Fishermen must walk farther, Hofer said, as do those using canoes and kayaks. The rowing club launches from the side of the old road, which is more of a challenge and means getting a bit muddier.
“It’s affecting everybody for sure because the water goes so far from the permanent structures,” Hofer said. “We can only move the docks out so far before the cable runs out.”
Nonetheless, it’s not something unexpected or new for the marina manager who’s been working on Lake Dillon for about 15 years. He remembers the reservoir being down 21 feet in the spring of 2005 and down about 6 feet in the fall of 2006. He added that he’s known all season about Denver Water’s plan to draw from the reservoir.
Hofer said because the drop is happening late in the season, with the summer tourism peak come and gone, it’s not drastically affecting the marina’s income or operations. He added that it’s still possible to get customers in and out of the water – even if it is more difficult.
The marina closes for the season Oct. 17, with crane day slated for Monday, Oct. 11. Neither date is unusual. Meanwhile, the Dillon Marina launch ramp is available to 60 feet down during the hours of 8:30 a.m. to 5:30 p.m., weather dependent, until Sunday, Oct. 24.
“We adapt, overcome and modify. We can’t control it. It is what it is,” Hofer said. “We’re used to changing water levels. It’s not as bad as it seems or looks.”
The Cheesman Reservoir technical rehabilitation project involves divers who need water levels to stay high and steady, Chesney said. Cheesman Reservoir is in the South Platte drainage system near Deckers.
“Fluctuating water levels wouldn’t be ideal for that type of work,” she said. Instead of drawing from the South Platte system, water is flowing from the Dillon Reservoir through the Roberts Tunnel, into lower reservoirs and toward the Denver water treatment plants.
The two-year, $18.3 million Cheesman project is part of a 10-year capital plan to replace and rehabilitate aging infrastructure throughout the state. Divers work 24 hours a day, seven days a week to upgrade the dam’s valve system, including installing trash racks to prevent debris from clogging the valves. Crews also will install new control systems and a control building and will update the dam’s electrical systems.
The improvements are being made to a dam that contains original infrastructure dating back more than a century, Chesney said.
“We are making upgrades to protect dam safety as well as continuing to provide a reliable water supply and smooth operations of our dams,” she said. “It’s time to make upgrades to the (Cheesman) system.
“It’s a pretty intense technical project,” Chesney said, adding that it’s the largest scale rehabilitation project Denver Water has done in recent history. Similar work was done at Gross Reservoir near Boulder.
She and Bob Steger, Denver Water’s manager of raw water supply, pointed out that they try to draw “strategically” from each water system. When the Cheesman project is complete, it will be a primary water source for Denver throughout the winter.
The Cheesman project is slated for completion in early December, at which point the Roberts Tunnel will be shut off. In mid-December, work will begin on the tunnel to replace and refurbish valves. It’s slated to take all winter.
SDN reporter Janice Kurbjun can be contacted at (970) 668-4630 or at email@example.com.