Flood control plan chosen for Boxelder Creek

By Cherry Sokoloski
North Forty News

Wellington and properties near the Highway 14/Interstate 25 interchange will be the big winners if a Boxelder Creek flood mitigation project is built.

In May, the Boxelder Creek Regional Alliance adopted its preferred plan to minimize the impacts of flooding from the creek. The plan calls for enlarging Clark Reservoir on Coal Creek north of Wellington and building a new facility, to be called the Edson Reservoir, south of Wellington at the confluence of Indian Creek and Boxelder Creek. The reservoirs would be sized large enough to take care of the entire Boxelder Creek drainage area, according to Rex Burns, an engineer with Larimer County.

In a report from the May 11 meeting, Burns said the plan will deliver "the greatest flood mitigation benefit per dollar of cost."

By enlarging Clark Reservoir, all but a small residual flow from the Coal Creek floodplain would be removed, thus taking most of Wellington out of the 100-year floodplain.

With the combined reservoir storage, Boxelder Creek flows would be reduced by one-third, and Cooper Slough flows would be reduced by about one-half at Highway 14.

Burns pointed out that the plan would provide "a significant benefit for existing and proposed land uses in the vicinity of Highway 14 and I-25." By adding storage at the two reservoirs, the need for additional diversion facilities downstream would be eliminated, he said.

Members of the Alliance include Fort Collins, Larimer County, Wellington, Windsor, Timnath, a group of property owners and a couple of irrigation companies. While Timnath has participated in the alliance all along, the town has opted to build its own diversion structure, at a cost of $4 million to $5 million, because it can be accomplished much more quickly than reservoir construction.

According to Timnath Town Administrator Becky Davidson, the town's diversion structure is being designed this year, with construction anticipated in 2007. Alliance members estimate that construction of storage facilities could take a minimum of three years.

No figures were available for the entire cost of the Boxelder project, but Phase I improvements are estimated to cost from $14.2 million to $16.1 million.

Consultant PBS&J will produce a draft of a Boxelder Creek Storm Water Master Plan calling for construction of the two reservoir facilities. One of the purposes of the master plan is to identify improvements that have regional impact and could be considered for regional funding, Burns said.

The next meeting of the alliance is set for June 20, 1:30 p.m., in the Carter Lake Room of the Larimer County Courthouse Office Building. At that meeting, alliance members are expected to accept the master plan and refer it to the member jurisdictions for adoption.