Northern Water entered its 2026 allocation cycle with storage above long-term averages and a weak snowpack forecast, forcing a familiar question for Colorado-Big Thompson board members: How much water can you safely deliver this year without compromising next year?
It looks like it will be another dry year. After a winter of low snowfall and warm temperatures, many resorts are cutting their losses early this spring and closing up shop for the season. Farmers and plant enthusiasts are considering the availability of irrigation water throughout the growing season.
Even residents across the Front Range's growing population are preparing to stretch a limited water supply as they watch the green grass peek its blades above the soil line.
Colorado is no stranger to drought. During the 1930s, water scarcity forced many farms into foreclosure. In response, a transmountain diversion that could bring water from the Colorado River to the East Slope was proposed. In 1957, after 20 years of regulatory and funding hurdles, the project was completed.
Other large U.S. systems were built to mitigate similar challenges in the 20th century. California’s Central Valley Project and State Water Project move water long distances and rely on annual allocation percentages tied to hydrology, while Arizona’s Central Arizona Project distributes Colorado River water based on priority tiers during shortages.
The C-BT Project, which is owned by the Bureau of Reclamation and managed by Northern Colorado Water Conservancy District (known as Northern Water) includes 12 reservoirs, 35 miles of tunnels, 95 miles of canals, and 700 miles of transmission lines. Today, it provides a supplemental water supply to nearly 1.1 million residents and 615,000 irrigated acres.
“It helps build on what the local water suppliers can produce,” says Jeff Stahla, Public Information Officer of Northern Water. “It’s incredibly important because it can smooth out the highs and lows of hydrology.”
Allocation of the water
The project was originally estimated to deliver 310,000 acre feet, which were divided into 310,000 equal shares.
“As the construction came to a close, leadership recognized that the project could not produce 310,000 acre-feet every year but that it would still meet the supplemental needs of the region by providing larger amounts during dry years and lesser amounts during wet years,” said Stahla.
To manage this, the quota system was created to allow the board of directors to set the maximum amount of water to be released each year. If the quota was set at 100%, then it would deliver one acre-foot per share; if it was set at 70%, it would deliver 0.7 acre-foot per share. Quota decisions weigh projected inflows against existing storage and multi-year carryover targets, rather than a single-season outlook.
High precipitation fluctuations in the past have meant that the C-BT has rarely needed to deliver large quotas for consecutive years. However, “rarely” does not mean “never.”
In the early 2000s, Colorado experienced an extreme multiyear drought, stressing cities and farms and testing the water infrastructure.
In 1999, the quota was set at 80%. In 2000, it was set at 100%, delivering the full acre-foot per share to water-stressed areas. The following year, the quota was set at 90%.
By 2002, the high quotas from previous years collided with the height of the drought. Despite it being the driest year, the quota was set at 70% because the reserves had been drawn down.
“We learned this year’s distribution can affect next year’s distribution and the year after,” Stahla said.
Allocations for 2026
More normal precipitation patterns from the last two years led to the C-BT Project reserves being above the 69-year average when the Northern Water board of directors went into its annual meeting to set the quota on April 9.
According to Northern Water’s announcement, while the board discussed that the dry conditions could have warranted a maximum quota, they announced an allocation of 80%, reflecting a more conservative approach and offering more flexibility if drought persists.
Meeting the needs of a changing demographic
Originally, the C-BT served mostly agricultural purposes. While agriculture is still the largest user of the C-BT water, over the decades, more and more shares have been converted to municipal use as the area evolves.
“As more water has been owned by municipalities, they have been more conservative and have not used every drop of their quota most years,” said Stahla. Northern Water has created programs to ensure that users are not penalized for not using their full allocation, incentivizing keeping more water in the system.
Northern Water also altered when the allocations were announced in response to the changing demographics. Until 2002, quotas were announced in April. Perfect timing for Colorado farmers, but it wasn’t as useful to municipalities that might need winter water delivery. “With more units now being owned by cities, they need to know there is a balance in their accounts at the start of the water year,” said Stahla.
An initial quota is now set in November, typically at 50%, followed by an April supplemental quota, granting cities more flexibility and clarity.
Lessons learned
As other states contemplate large-scale water transfers, the C-BT offers some lessons learned after nearly 70 years in operation. “Number one would certainly be patience,” said Stahla.
He also notes that the length of these projects is important because they often span different administrations.
“One administration might give you what seems like an edge, but you need to be thinking really long term on these,” Stahla said. “Being conservative on those permitting efforts really helped us.”
As water professionals face changing environmental factors, demands, and demographics, projects like the C-BT will continue to provide an example of flexibility but also preparation.
“For the past 10 years, we’ve had relatively normal precipitation in Northern Colorado, which sometimes leads people to ask, ‘Why are you building these reservoirs?’” said Stahla. “Years like these are nature's reminders to us that we need to collect water when we have it available so that we can use it when we need it.”
