A town official says the building of Rueter-Hess Reservoir and Dam has cut the risk of major flooding in Parker-area gulches and will save millions of dollars on mandatory safeguards for bridges.
The last time Parker or the Federal Emergency Management Agency conducted a comprehensive study of major drainage ways was 1977, and a lot has changed since then, says Tom Williams, manager of the town’s engineering and stormwater division.
The Town of Parker and Douglas County, along with the Urban Drainage and Flood Control District, are revising a master plan that considers everything from flood flow rates to erosion along Newlin Gulch and Baldwin Gulch. The master plan will include updated analyses and computer models, as well as identify existing and potential future issues.
The most noticeable change since the 1977 study is the construction of Rueter-Hess Reservoir and Dam, a 72,000-acre-foot water storage reservoir and 185-foot structure southwest of Mainstreet and Chambers Road. Williams believes the master plan research will reveal a significant reduction in flood danger from a 100-year event, which means that instead of building or replacing a $1 million span bridge, the town could put in a box culvert at less than half the cost.
“We’re not talking small money. We’re talking about millions of dollars here,” Williams said.
It’s difficult to estimate the overall long-term savings, and officials won’t know until the completion of the $200,000 analysis how much massive flood flows would decrease. But Williams gives the example of a drainage ditch that crosses Recreation Drive, a small thoroughfare west of Challenger Park that runs behind the King Soopers at Lincoln Avenue and Jordan Road, as one area where cost-savings might be realized.
The million-dollar bridge project has been on the books for years but was delayed because of the steep construction costs. The revised master plan will probably reveal that a culvert could easily withstand the strongest flows, Williams said, precluding the need for a large bridge structure with concrete pillars and reinforced materials.
“If a 100-year event occurs in Newlin Gulch, when the reservoir wasn’t there, there would be a big wall of water coming down the gulch,” he said.
There are several major bridges over Newlin Gulch that will eventually need to be replaced or expanded, including ones on Chambers Road, Jordan Road, Lincoln Avenue and Mainstreet. Those projects range in cost from $100,000 to more than $1 million, but culverts might become the preferred option.
The benefit, albeit unintended, was welcome news for Town Council, and was met with kind words from the Parker Water and Sanitation District. Relations between the entities are thawing after years of tension, and the reduced financial burden on the town resulting from the reservoir could further repair any bad feelings.
“If in their analysis of storm flows, the town is able to reduce the size and therefore the cost of future bridges, then this is a nice win for residents of the town,” said Jim Nikkel, project manager for the district.
In all likelihood, the reservoir already prevented erosion damage from a major rainstorm in early July, Williams said. The Parker Water and Sanitation District, which is only allowed to capture a portion of the flows in Newlin Gulch, has the ability to control the amount of water that is released by the dam.
The Urban Drainage and Flood Control District is paying $100,000 of the cost for the watershed study, and Parker and Douglas County are contributing $70,000 and $30,000 respectively. A master plan update was delayed for 35 years because town planners knew the completed reservoir would change predictions for flood flows.