Boulder staff report adequate local supply this year; Northern Water urges attention to Colorado River negotiations

City of Boulder water staff and Northern Water officials told the Water Resources Advisory Board at an April meeting that local water-storage indicators and streamflow forecasts point to a year in which the city is unlikely to declare drought use restrictions, while stressing that broader Colorado River negotiations remain unresolved.

Crystal Mori, senior water resources engineer for the City of Boulder, said the city’s projected storage index (PSI) is about 1.4 — above the drought-alert threshold in the city’s drought plan — and that staff do not currently expect to implement mandatory water-use restrictions. “Preliminary analysis indicates that the PSI is around 1.4, which is comfortably above the 0.85 and at a level where we would not anticipate the need to declare drought restrictions,” Mori said.

The PSI is a ratio of expected supply to anticipated demand that incorporates current reservoir storage in Boulder Creek watersheds, anticipated allotments from the Colorado-Big-Thompson (CBT) system and a 10‑year demand baseline that reflects recent conservation. Under the city’s drought plan, a PSI between 0.85 and 0.56 would trigger a Stage 1 drought alert with a target of up to 20% water savings and limits on lower‑priority outdoor uses.

Mori reviewed supply indicators: South Platte Basin snowpack at roughly 88% of median, Colorado‑headwaters snowpack at about 77% of median, University Camp snow sites at about 90% of median and Lake Eldora at 63% of median (Lake Eldora has already peaked and begun melting). Streamflow forecasts shown to the board were near average, and Northern Water had set an “average” CBT allotment for the year. Mori said the city expects mountain reservoirs to fill this year but will continue to monitor conditions through the summer.

Northern Water General Manager Brad Winn and Water Rights Manager Kyle Whittaker briefed the board on the Colorado River system and ongoing multistate negotiations over operations of Lake Powell and Lake Mead. Whittaker summarized the compact framework and compliance measures that affect reservoir operations and deliveries. He described the compact’s 10‑year average compliance point at Lee Ferry and explained why that averaging system makes operations and negotiations complicated as reservoirs fall and rise.

Whittaker and Winn described the current negotiations as focused not on rewriting the Colorado River Compact but on operating criteria for Powell and Mead after the 2007 interim guidelines expire. They said parties are evaluating alternatives that would balance storage protection and deliverable allocations; some proposals would require larger cuts from Lower Basin users, and others would ask additional contributions from the Upper Basin.

Northern Water staff reiterated technical points about CBT and Windy Gap supplies. Board members asked about how CBT quotas are set; staff explained the quota is a board decision for Northern Water and that, earlier this year, Northern set an 80% CBT quota as the working allocation across its units (Windy Gap orders are administered differently). City and Northern staff also discussed how CBT return flows support South Platte tributary reservoirs and how removing those deliveries could change local streamflow patterns.

Board members asked about long‑term trajectories under climate change. Northern Water staff said modeling includes drought and climate scenarios and that a lower long‑term average inflow would require much larger, basin‑wide adjustments to operations and uses. Both city and Northern staff stressed that municipal per‑capita use has declined in recent decades while total demands have grown with population and development.

The city said it will keep monitoring PSI, snowpack, streamflow forecasts and Northern Water allotments and will revisit drought status if conditions change.

Ending: Staff scheduled continued monitoring through the summer and said any decision to declare water‑use restrictions would be brought back to the board and to city officials for review.