The May 8 board meeting of the Upper Arkansas Water Conservancy District featured updates on two Custer County water projects – Round Mountain Reservoir and Wenke Pond.
Project Implementation Manager Gracy Goodwin reported that the State Engineer’s Office (Colorado Division of Water Resources) recently approved design and construction drawings for Round Mountain Reservoir.
Upper Ark District Hydrologist Jord Gertson reported that the District has completed work on the Wenke Pond that will allow the pond to be used as a source of augmentation water for a key segment of Grape Creek.
Round Mountain Reservoir is a joint project between the Round Mountain Water and Sanitation District and the Upper Arkansas Water Conservancy District. It is proposed to be built near Grape Creek just south of Westcliffe.
The Round Mountain District provides municipal water services for approximately 1,000 residents of Westcliffe and Silver Cliff but faces challenges exacerbated by limited resources.
District Engineer Chris Manera, who has studied the feasibility of the project, said one of those challenges is a municipal well “that can deplete Grape Creek.”
He said having the 150-acre-foot reservoir upstream will help protect that well and, therefore, the municipal water supply for residents of Westcliffe and Silver Cliff.
Essentially, when water use in the two towns threatens to deplete flows in Grape Creek, the proposed reservoir will allow the Round Mountain District to release water to the creek to maintain streamflow.
Manera said officials with the Colorado Dam Safety Program rated the dam as a “low-hazard dam,” which represents “no risk of loss of life or structures.”
Goodwin said she is working with Engineering Analytics, the firm that created the reservoir design, to write up bid documents for the project.
Gertson reported that the Wenke Pond provides 12.35 acre-feet of storage that will serve as a source for replacing water used out of priority on a portion of Grape Creek.
Paul Wenke, owner of the pond, approached the Upper Ark District in 2021 after State water officials began to implement a new pond-management plan.
The Division 2 Engineer’s Office (Colorado Division of Water Resources) manages water rights in the Arkansas Basin and implemented the pond-management plan after identifying more than 10,000 ponds, including the Wenke Pond, with no legal right to store water.
The ponds represent an illegal use of water because (1) they don’t have a court-decreed right to store water and (2) storing water in reservoirs increases evaporation, thereby taking water from senior water-rights owners.
In January 2022, the Conservancy District board of directors approved an agreement with Wenke that prevented him from having to drain his pond.
Under the terms of the agreement, the Upper Ark District will replace the pond’s evaporative water losses and will be able to store water in the pond to replace other out-of-priority water use on Grape Creek.
As previously reported, Wenke paid the District a $5,000 application fee and agreed to pay $660 per acre-foot of water stored per year.
The District agreed to pay an estimated $15,000-20,000 to cover fees, install measuring devices and modify the outlet structure to allow for the pond’s water level to be raised and lowered as needed.
At the May 8 board meeting, Gertson said contractors had temporarily drained the pond and installed a new outlet pipe equipped with a gate valve that “will allow water-level control for administration purposes.”
Gertson noted that the contractor also performed some excavation to increase the pond’s storage capacity and enhance its utility as a source of augmentation water. “We still need to install a staff gauge,” he added.
Upper Ark District Advisor Terry Scanga said that all of the Water Court decrees that will allow the pond to be operated as an augmentation structure have been issued.
Image: The red dot at the bottom of this satellite image shows the proposed location of the Round Mountain Reservoir just south of Westcliffe. DeWeese Reservoir can be seen at the top of the image (image courtesy of the Upper Arkansas Water Conservancy District).
