Longmont to begin building Heron Lake flood mitigation channel — Longmont Times-Call

Heron Lake flood relief channel project vicinity map via Times-Call and the City of Longmont
Heron Lake flood relief channel project vicinity map via the Times-Call and the City of Longmont

From the Longmont Times-Call (John Fryar):

Construction is to start in early August on the project, which will include a spillway and low-flow outlet structure that will be built at Heron Lake — the easternmost pond on Boulder County’s Pella Crossing open space area about ½ mile west of Airport Road — as well as a drainage channel from the lake south to the St. Vrain River and a maintenance road alongside that channel.

In September 2013, a breach on the St. Vrain River’s north bank resulted in floodwaters filling and overtopping the ponds at Pella Crossing, with the sheet of water eventually crossing Airport Road north of the river and affecting more than 400 properties after entering the city’s Longmont Estates Greens, Champion Greens, Golden Ponds Estates and Valley subdivisions.

The Heron Lake Relief Channel drainage system will intercept any floodwaters in Heron Lake and divert that water back to the St. Vrain River rather than having them flow east into Longmont, according to a news release from the city’s Public Works Department and Boulder County’s Parks and Open Space Department…

It will span three property parcels. Two, including Pella Crossing and land adjacent to the river, are owned by Boulder County, and the third is owned by the private Golden Land Company, which eventually plans to mine gravel there.

The city is the lead agency on the project. Boulder County, which assisted in the planning and engineering, is contributing $100,000 in funds it’s getting from the Federal Emergency Management Agency toward the $925,000 estimated total design and construction cost. City officials said Longmont is pursuing federal Community Development Block Grant-Disaster Recovery funds to cover the rest.

More St. Vrain River coverage here.

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