Southern Water Supply Project

The Southern Water Supply Project pipeline carries Windy Gap Project and Colorado-Big Thompson Project water 110 miles from Carter Lake to several Northeastern Colorado communities. Plans for year-round deliveries through the pipeline began in 1991.

Alternate Supply for Broomfield
In the early 1990s Broomfield received half its water from Great Western Reservoir, located downstream of Rocky Flats, a former nuclear weapons facility. Due to potential contamination of the reservoir, the U.S. Department of Energy agreed to provide Broomfield with an alternate water supply.

At that same time a regional study forecasted an increasing demand for water in the southern portion of Northern Water's service area. Communities facing higher water quality standards needed reliable year-round water deliveries.
The proposed Southern Water Supply Pipeline met Broomfield's needs and could also provide other communities with a year-round water supply. In addition, sharing a single pipeline would be less costly than if each participant built its own project.

Pipeline Construction
Construction on the first phase of the pipeline, from Carter Lake to Broomfield, began in 1993. The last 41-mile section from Platteville to Morgan County was finished in 1999. 

Due to project participants' increasing water demands, particulary during the higher-demand summer months, a West Longmont pump station was added in 2003. Two years later an additional pump station at Broomfield followed.

A third pump station on the eastern section of the pipeline will be built when needed. Together, the three pump stations will increase system capacity by 80 percent.

Southern Water Supply Project map
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Twelve Project Participants
Northern Water owns and operates the Southern Water Supply Project pipeline, while individual participants have contractual rights to the water. Total project constructions costs were $68 million.

The project participants are:
  • Fort Morgan
  • Broomfield
  • Hudson
  • Berthoud
  • Longmont
  • Erie
  • Louisville
  • Morgan County Quality Water District
  • Little Thompson Water District
  • Central Weld County Water District
  • Superior
Southern Water Supply Project II

Design and right-of-way activities are underway for the Southern Water Supply Project II, a 20-mile pipeline from Carter Lake Reservoir to the Boulder Reservoir. Learn more>>