LARIMER COUNTY — Final approvals for the Northern Integrated Supply Project, a large water development project that will include construction of two new reservoirs in Northern Colorado, have not yet been granted, but motorists on U.S. Highway 287 north of Fort Collins will begin to see activity beginning in June.

The Northern Water Conservancy District, the water project developer, posted information on its website today indicating that geological crews will be on site in areas visible from U.S. 287 assessing rock and soil aspects of the dam site for the future Glade Reservoir necessary for design purposes. The work may last up to six months.

Advancing design work now, even before final approvals, helps Northern Water compress the project timeline. 

If the U.S. Army Corps of Engineers makes its final determination this year, then construction could start as early as 2023 with the Glade Reservoir ready for water by 2028.

Glade Reservoir will be a 170,000 acre-foot reservoir that will displace about seven miles of U.S. 287 when it is built. An acre foot is 326,000 gallons, enough water to cover an acre one-foot deep.

Relocation of the highway could begin as soon as 2023 if approvals come this year.

Glade, according to previously reported project details, would be joined by another new reservoir, Galeton, a 45,600 acre-foot reservoir northwest of Ault. In all the project will cost about $1.1 billion and be paid for by water users in 15 communities or districts: Central Weld County Water District, Dacono, Eaton, Erie, Evans, Firestone, Fort Collins-Loveland Water District, Fort Lupton, Fort Morgan, Frederick, Lafayette, Left Hand Water District, Morgan County Quality Water District, Severance and Windsor.

The work to begin in June, called the Glade Reservoir Geotechnical Design Assessment, will help to inform design and construction planning, the water district said on its website. Work will include:

• Digging a 1,000-foot-long trench at the main dam for material testing and foundation drilling.
• Constructing a test pad of embankment material types.
• Producing aggregates and rock fill from the quarries and investigating material characteristics.

If work proceeds like it has on the Chimney Hollow reservoir west of Carter Lake in Larimer County, all the aggregates necessary for the dam and its foundation will be quarried on site to avoid having to haul massive amounts of material in or out of the reservoir footprint.