Berth trustees hear water‑supply roadmap; staff urges firming Windy Gap units and treatment expansion

Berth — Town water officials on Tuesday delivered a detailed briefing on the municipality’s water portfolio and its plan to match supply with projected growth, urging trustees to pursue storage that would “firm” delivery from variable Windy Gap allocations.

At the meeting, Water Utilities Director Ken Matthews and consultants from Spheros and other firms laid out the town’s current mix: roughly 1,822 acre‑feet per year from the town’s decree water, about 653 acre‑feet tied to Colorado‑Big Thompson (CBT) units, and a variable yield from 10 Windy Gap units that can range from low to roughly 95 acre‑feet per unit if firmed. Matthews said the Windy Gap allocation “varies pretty significantly year‑to‑year,” and that the town should not base long‑term commitments on Windy Gap water unless it has firm storage.

“We are not going to advise the town to make any commitments based on a water supply that is not firm,” said Ken Matthews. “Firming means having a place to store the water when it’s available so the town can use it in dry times.”

Why firming matters: storage options and tradeoffs

Presenters described two broad approaches to firming: obtain an interest in existing east‑slope reservoirs (for example, Dry Creek) or work toward participation in larger firming projects such as Chimney Hollow. Consultants noted Chimney Hollow cannot reliably deliver for several years because of a staged fill and water‑quality monitoring; current estimates put meaningful deliveries several years out.

Pete Johnson, who spoke for regional supply partners, said options are limited and often costly. “There’s a limited universe of methods and locations we can use to firm up Windy Gap supplies,” he said, noting that Chimney Hollow’s full availability will depend on multiyear testing and remediation work.

South Plat project and new junior rights

Staff also reviewed the South Plat water‑supply project, a multi‑component plan that includes new junior water rights recently decreed for Milikin and Section 20 reservoirs, a recharge facility and a well field that would yield water near the confluence of the South Plat and St. Vrain rivers. Those wells will be junior rights and would require replacement water through augmentation plans — typically the stored or reusable water the town can accumulate.

Spheros project manager Andrew Casease presented the semiannual "snapshot" used to guide the town’s water dedication policy. Under conservative drought assumptions, the town currently has about 535 acre‑feet of water credits that have been committed to developers but are not yet treated at the town’s plant ("unrealized demand"). The firming status of Windy Gap significantly changes how many single‑family equivalents the town can safeguard: under the most conservative (no Windy Gap yield) drought scenario the system serves roughly 9,000 single‑family equivalents; with a firm Windy Gap yield that capacity rises substantially.

Treatment capacity and timing

Trustees heard that the town’s existing water‑treatment plant is nearing capacity during peak periods. Staff recommended a roughly 1 million‑gallon‑per‑day (MGD) expansion as a first step. Ken Matthews said such a project typically takes about five years from siting through regulatory approval and construction in a realistic timeline, though construction alone is often nearer two years once approvals are complete.

“We shouldn’t wait to build the treatment capacity if we plan to bring significant new supplies online,” Matthews said. Staff are also evaluating regional treatment partnerships that could be faster or provide alternative sequencing.

Board response and next steps

Trustees asked for a simple spreadsheet summarizing the town’s shares, units, typical acre‑foot yield and general price guidance for reference; staff agreed to provide that. Several trustees emphasized the value of pursuing firm storage while simultaneously pursuing careful, phased plant improvements.

Staff identified immediate next steps: continue South Plat negotiations, pursue firming partnerships (Dry Creek and other storage interests), finalize the water‑treatment expansion scoping and update the water‑dedication policy at the board’s next snapshot review.

Provenance: This article is based on the water portfolio and snapshot presentation and Q&A (timeline entries covering SEG 1250–SEG 3271).