Staff outlines water‑supply constraints, Longmont agreement and options for housing growth

Aaron, the town’s utility/UEP director, briefed the panel on Lyons’s water supply and how intergovernmental agreements with Longmont shape growth capacity. He described three primary water sources the town relies on: native Saint Vrain/Saint Brain Creek rights, Colorado‑Big‑Thompson (CBT) units and Lake McIntosh shares. On relative cost he told the group: "One unit of this CBT is probably $60,000 currently," and said Lake McIntosh shares have been explored as a lower‑cost alternative for some affordable housing strategies.

Aaron explained how the Longmont IGA frames buildable capacity: "Our agreement is we can have 1,200 and something service connections. We currently have over 900," he said, and staff estimated roughly 300 remaining 0.75‑inch equivalents under the current arrangement. Staff said Longmont has indicated those remaining connections could be supported if the town requires either 1 CBT or 1.5 Lake McIntosh shares per typical single‑family equivalent, but staff also said the town would need to renegotiate the IGA if the town sought significantly more connections.

The briefing covered technical details (CBT yield variability, Northern Water allocation percentages, and how connection size correlates to unit requirements) and policy implications: because CBT costs have risen sharply, Lake McIntosh shares were presented as a potentially less expensive option for targeted affordable housing, but supply and matching rules would need coordination with Longmont. Staff will include the water‑supply narrative, test sites and high‑level infrastructure cost estimates in the comp‑plan addendum submitted for SB 24‑174.