A JOINT AGENCY WATER SUPPLY PROJECT

The Cherry Creek Project Water Authority (CCPWA) is a Colorado Title 29 Authority formed in 2005 through intergovernmental agreement between the Inverness Water and Sanitation District, the Pinery Water and Wastewater District and the Cottonwood Water and Sanitation District and the Town of Castle Rock. The Authority was formed in order to purchase and develop water supplies for these four entities from the upper Cherry Creek Basin. The Authority purchased surface water and ground water rights, and property intended for reservoir construction from Western Water Company, a privately held water company. The Authority then purchased additional senior surface water and alluvial rights and deep groundwater in upper Cherry Creek. The Authority then developed a Master Plan and used the plan as a basis for a water rights application for these rights and an augmentation plan to utilize this water. The plan was decreed as 10CW318 in 2015. The Authority is now implementing the plan by constructing facilities.

This project is the construction of a 650 acre-foot reservoir located directly adjacent to Cherry Creek near Franktown, Colorado. There is currently an abandoned gravel pit at this location which contains alluvial ground water fed by Cherry Creek. The plan is to expand the volume of this gravel pit and seal the pit from Cherry Creek with a concrete slurry wall. The Walker Reservoir is part of the facilities required to develop a conjunctive use water supply project as described in the Cherry Creek Project Master Plan. The CCPWA has decreed tributary water rights amounting to 1,265.9 acre-feet of water supply on Cherry Creek. These water rights are senior and junior water rights with appropriation dates of 1885 to 1984. This project is intended to maximize the development of these surface water supplies. This project will allow for storage of up to 2,000 acre feet per year which is the decreed annual storage volume with fill and refill. The project is to divert senior and junior surface water rights when they are in priority. The annual yield of the project will be firmed by using deep ground water rights. The deep groundwater utilized for firming each year as necessary, is a small percentage of the total decreed ground water of 7,699.1 acre-feet. 

Water will be diverted from Cherry Creek through an alluvial wellfield and pumped into the reservoir. 

The water in the reservoir will be used directly by the Pinery Water and Wastewater District through releases to Cherry Creek and then pumping the water into their water distribution system a short distance downstream using existing alluvial wells. The other participants (Inverness Water and Sanitation District, the Arapahoe County Water and Wastewater Authority, and the Cottonwood Water and Sanitation District) will move the water downstream from Walker Reservoir during conditions where the stream is live either to points of diversion for direct use or may trade water for other sources such as WISE water. The plan also considers moving the water via Cherry Creek to Rueter Hess Reservoir subject to the Parker Water and Sanitation District’s willingness to lease or sell diversion and storage capacity. Storage in Rueter Hess would greatly expand the window of deliveries and hence would improve the participants’ capability to manage the water supply.