The Upper Arkansas Water Conservancy District is working with Round Mountain Water and Sanitation District to advance a new reservoir project in Custer County.

Projects Manager Gracy Goodwin provided an overview of the project at the July Upper Ark district board meeting. She said the two districts began collaborating on the project to address the need for a source of augmentation water on Grape Creek upstream from DeWeese Reservoir.

Goodwin said the two districts are seeking grant funding for the Round Mountain Reservoir Feasibility Study and Design project. Round Mountain conducted a preliminary feasibility study that laid the groundwork for the current project.

The proposed 7-acre reservoir would be built on land owned by Round Mountain and would have a storage capacity of approximately 150 acre-feet, Goodwin said. “The goal would be to start construction within 3-5 years.”

The Round Mountain district provides water and sanitation services to the towns of Westcliffe and Silver Cliff and lies within the boundaries of the Upper Ark district in Custer County.

Custer County Commissioner Tom Flower, an ex officio member of the Upper Ark board, said, “I believe this is a great project. I think there’s going to be a desperate need.”

Director Mike Shields represents Custer County on the Upper Ark board. He said the proposed reservoir site is “in an excellent spot” just south of Westcliffe, which is upstream along Grape Creek.

Goodwin noted that the reservoir project meets multiple objectives of Colorado’s Water Plan, including:

  • New water storage capacity.
  • Increased storage and reliability for municipal water supplies.
  • Maintaining the Grape Creek ecosystem.

Goodwin said the feasibility study would include:

  • A water rights and hydrologic analysis.
  • A streamflow analysis.
  • A geotechnical investigation.
  • Development of conceptual design alternatives.
  • An environmental permitting review.

The design component of the new project would include dam design and engineering and pump station design.

Goodwin also said that the proposed reservoir site is off-channel and that augmentation water (water released from the reservoir to replace out-of-priority water use) would be returned to Grape Creek at the same location from which it would be diverted, with diversions only occurring during high streamflow conditions.

Board Vice Chair Greg Felt asked if the reservoir would be accessible to the public for recreation purposes.

District General Manager Terry Scanga said that decision would be “up to Round Mountain” since they own the property. He also noted that, as an augmentation reservoir, “it could be drawn down almost all the way” during drought conditions, which would be detrimental for recreational uses.