Rueter-Hess Reservoir, storing water behind the Frank Jaeger Dam, is in operation and has stored as much as 30,000 acre-feet (“ac-ft”). However, it has taken a lot of effort to bring this centerpiece of the Parker Water and Sanitation District (“PWSD”) water supply system to fruition. This series of blogs tells the story of the development of Rueter-Hess Reservoir.

In the early 1980s, PWSD prepared a Master Plan that indicated, with the expected future growth at that time, the district could have a water supply shortfall of approximately 3,000 acre-feet per year (“ac-ft/yr”). At that time the district was mostly dependent on the KOA alluvial aquifer well, with some of its supply being provided by limited Denver Basin aquifer wells.

The KOA well water right is relatively junior in the priority system (1946); however, at that time, Cherry Creek upstream of Cherry Creek Reservoir was not being administered, i.e. it did not have to operate pursuant to an augmentation plan (see LWS blog on Augmentation Plans, posted on April 17, 2019). Therefore, the KOA well could produce a large portion of the district’s water demand. This was because the KOA well could produce approximately 1,800 gallons per minute, and there were only a few hundred water taps requiring water service in Parker at that time. We understood the lack of water rights administration would probably not be the case in the future, therefore, the water supply needs assessment also accounted for the potential that the KOA well would not be a large part of the future reliable PWSD water supply due to significant periods of time when the right would be “out of priority.”

Because of the perceived future water supply shortfall, the district commissioned a study led by Mr. Bruce Lytle to identify potential sources of supplemental water supplies to meet this shortfall. An initial study by Morrison Knudsen Engineers (“MKE”) and Mr. Lytle identified three potential reservoir locations in the upper Cherry Creek Basin, including:

Castlewood Canyon;
Bridge Canyon; and
Confluence

***Figure 1:*** *Potential Reservoir Sites (1985).*

The general locations of these reservoir sites are shown in Figure 1. Based on the hydrology at each site and the administrative practices at the time, each of these reservoir sites was deemed adequate to meet PWSD’s future water supply needs, based on water supply availability on Cherry Creek at these locations. Based on the analysis of these sites from a preliminary geotechnical perspective (MKE) and from a hydrology and water rights perspective (Mr. Lytle), a Water Court application was filed in 1985 in Case No. 85CW448.

During the pendency of the case further analysis of the reservoir sites was conducted and it was determined that the preferred reservoir site was rebuilding the Castlewood Canyon dam within Castlewood Canyon State Park. The original Castlewood Canyon dam was built in 1890 but had seepage problems from the beginning. The dam finally failed during a storm event in 1933. Some history on the Castlewood Canyon dam can be found at:

https://cpw.state.co.us/placestogo/parks/CastlewoodCanyon/Documents/Castlewood-CanyonDam.pdf

The rebuilt Castlewood Canyon dam was preliminarily designed to store approximately 24,000 ac-ft. With expected significant times when the junior water right sought in 85CW448 would be out of priority, this much storage was judged to be necessary to provide a firm yield of 3,000 ac-ft/yr for PWSD.

With the dam being situated within the State Park, PWSD was required to obtain approval from Colorado State Parks to be able to proceed with the project. However, after negotiations with the State Parks Board, PWSD’s request was denied in 1991. Good reservoir site, but no access to build the dam. Therefore, PWSD had to come up with a Plan B to obtain the needed reservoir storage. Watch for Part 2 of the Rueter-Hess Reservoir history blog series to learn where PWSD went next.

If you need any help with developing new or supplemental water supplies, whether surface water or groundwater, LWS can help. Please give us a call (303-350-4090) or an email.

Bruce Lytle bruce@lytlewater.com

Chris Fehn chris@lytlewater.com

Ben Bader ben@lytlewater.com

Anna Elgqvist anna@lytlewater.com