Water Advisory Board – August 2026: Drought Planning, Water Exchanges, and WaterFair Results

Longmont’s water system is built for difficult years, but this summer is a reminder that preparation does not make drought disappear. It gives us more options for responding to it.

At the August Water Advisory Board meeting, the conversation covered current stream and reservoir conditions, a proposed short term water rights exchange to support augmentation in the St. Vrain Basin, the impact of the 2026 WaterFair, and continuing work on conservation, infrastructure, and water policy.

Table of Contents

• Water Conditions: Low Creek Flows and Strong Reservoir Storage
• A Proposed Water Rights Exchange for the St. Vrain Basin
• Water Exchanges Are a Regular Part of Basin Management
• WaterFair 2026: Connecting Art, Science, Policy, and Water
• Conservation, Code Updates, and Future Water Board Topics
• Longmont’s Position During Regional Voluntary Restrictions

Water Conditions: Low Creek Flows and Strong Reservoir Storage

Water calls remain active across the basin. A call is in place on the Lower Platte and Beaver Canal system, on St. Vrain through the Wacott Turner Ditch, and on Lykins Gulch through the Niwot or Nelson Ditch. Staff are also continuing conversations with water users on Dry Creek, including Upper Baldwin, Lower Baldwin, Rice Ditch, John Rice Ditch, and Coffin Davis, to determine whether a coordinated call can be established there.

Those conversations matter because a water call only works when the affected users can participate in the administration needed to protect senior rights and account for available flows. Dry Creek coordination has been challenging, but work is continuing.

Creek conditions remain exceptionally dry. The St. Vrain flow at Lyons was about 26.5 cubic feet per second during the meeting, far below typical historical conditions. Boulder Creek was reported at approximately 5.5 cubic feet per second at the gauge, with much of that limited flow being diverted.

Reservoir storage provides an important counterweight to those low streamflows:

• Union Reservoir: 56.9% full, holding about 7,264 acre-feet.
• Button Rock Reservoir: 99.18% full, holding about 16,175 acre-feet.

Button Rock remaining nearly full is a major part of Longmont’s drought resilience. It allows the city to protect a high quality, high elevation supply while continuing to meet water needs through a broader portfolio of sources and exchanges.

A Proposed Water Rights Exchange for the St. Vrain Basin

The board considered a proposed water rights exchange agreement with the St. Vrain and Left Hand Water Conservancy District. The agreement would be structured as an intergovernmental agreement because both parties are public entities.

The proposal is intentionally short term. It would last no longer than one year and would not renew automatically. That makes it possible to move forward through a City Council resolution rather than a longer ordinance process.

What Would Be Exchanged?

The district would provide Longmont with approximately 148.8 acre-feet of Colorado-Big Thompson water before the end of the irrigation season. In exchange, Longmont would make releases of fully consumable water to support the district’s augmentation plan at mutually agreed rates.

This is not simply water for water. The two supplies have different characteristics and can be used in different places within the system.

Colorado-Big Thompson water can be useful to Longmont for treatment plant supply, storage, irrigation, and other operational needs. Receiving that water lower in the system can reduce the need to release water from Button Rock Reservoir, which helps preserve storage during low flow conditions.

The fully consumable water Longmont would release is valuable to the district because it can be used to replace depletions under its augmentation plan. Those replacements help ensure that out of priority water uses do not injure senior water rights downstream.

Why the District Needs Augmentation Water

The St. Vrain and Left Hand Water Conservancy District’s augmentation program began during the late 1980s and early 1990s, when the state increased regulation of small wells, cabins, residential uses, and other water uses that had not previously been fully accounted for in the water rights system.

The district created an umbrella augmentation plan to account for those small depletions across the basin. Under this approach, replacement water does not necessarily need to be delivered at the exact same moment or location where the original use occurs. Instead, replacements can be made at other points within the basin so that the basin is satisfied from a water rights perspective.

The program now includes approximately 214 memberships. Most are in the St. Vrain Basin, and the program’s annual depletions total about 182 acre-feet, with roughly 160 acre-feet associated with St. Vrain Creek.

These are mostly small uses, but small uses add up. They include:

• Seasonal cabins and year round residences
• Domestic wells and indoor household uses
• Small lawn and garden irrigation pumps
• Small farms
• Commercial and nonresidential uses, including venues near the river and tributaries

Many members use less than one acre-foot per year, and some use only a fraction of an acre-foot. That makes meaningful reductions difficult. Reducing use across a large number of very small users is much more complicated than reducing one large diversion.

Storage Challenges at Lake Number Four

The district’s principal augmentation storage facility is Lake Number Four near Hygiene. The reservoir was heavily damaged in the 2013 floods and required a lengthy reconstruction effort. During that period, Longmont partnered with the district by making replacement releases in exchange for water, helping keep the augmentation program functioning while the reservoir was rebuilt.

The district also operates Copeland Reservoir near the entrance to Wild Basin, along with several direct flow rights and ditch company shares. But current conditions are tight. Lake Number Four is less than half full, holding about 280 acre-feet, and it has not filled in the previous two years. Direct flow rights are also producing less water as more senior priorities come into effect.

If conditions continue and Lake Number Four cannot fill next year, the district projects that its stored supply could be exhausted in 2028.

The proposed exchange would help preserve the water currently in Lake Number Four for future needs. The district would trade Colorado-Big Thompson water that it cannot use directly for augmentation, while Longmont would provide replacement water on the district’s schedule. It is a practical way to make two different water supplies work harder for the basin.

How Longmont Can Make the Releases

Longmont already manages a substantial set of replacement obligations tied to water court decrees, leases, exchanges, and other agreements. Daily accounting aggregates those requirements so the city can plan releases across the system rather than treat every obligation as completely separate.

The proposed exchange would be one additional component of that larger accounting process. Typical replacement releases are relatively small, generally in the range of about 0.2 to 0.5 cubic feet per second, with higher releases in summer and lower releases in winter.

Staff indicated that the obligation may fit largely within operational flexibility already maintained for daily releases, though it could mean operating with a little less extra margin at times.

Board Recommendation

Staff supported the agreement as beneficial to the basin, particularly under drought conditions. The board recommended moving forward with the proposed exchange agreement for City Council consideration.

The exchange also gives Longmont flexibility. The Colorado-Big Thompson water received could be directed to the water treatment plant, stored, used for irrigation, or applied to other city needs. Using that supply lower in the system can be more efficient than making additional releases from Button Rock during very low flow conditions.

Water Exchanges Are a Regular Part of Basin Management

Water exchanges are not unusual, although each one requires its own analysis. In a typical year, Longmont may receive roughly half a dozen to a dozen exchange requests. Agreements involving private entities can sometimes be handled more directly, while agreements with governmental entities require an intergovernmental agreement process.

The city currently has about a dozen existing agreements of this type. Staff generally use a 75 acre-foot minimum as a starting point because these arrangements require time, accounting, engineering, and legal review. Still, every proposal is evaluated individually.

Some exchanges are water for water. Others are water for money. The essential question is whether the arrangement makes operational, financial, and basin-wide sense.

WaterFair 2026: Connecting Art, Science, Policy, and Water

The meeting also included an impact report on WaterFair 2026, an annual community event built around the interconnectedness of water, art, science, culture, public health, and policy.

WaterFair is co-led by the city with local nonprofit, grassroots art, public health, and watershed partners. Its goal is not just to share information. It is to help people understand how water moves through homes, infrastructure, rivers, watersheds, communities, and ultimately the larger connected water system.

This was the third annual event, and it was the largest yet, with 425 participants, a 20% increase from the prior year. Eight languages were represented at the fair.

Following the Journey of Water

The first two years focused on where Longmont’s water comes from. This year’s theme was where our water goes.

The event was intentionally arranged as a journey through the water cycle. Participants began with water use in the home, then moved through stormwater, wastewater treatment, creek health, water law, agriculture, and the broader watershed.

The event included nine core stations, a reduction from previous years after feedback showed that too many stations made the experience harder to navigate.

Station themes included:

• Water use in homes
• Stormwater
• Wastewater treatment
• Nature-led design and the Resilient St. Vrain Project
• St. Vrain biodiversity
• Healthy watersheds
• Youth water art
• Agricultural water use
• Water law and prior appropriation

The wastewater treatment station was especially hands-on. City staff used an interactive activity involving floating poop emojis to explain the real work of removing waste from water before it is returned to the creek. It may sound silly, but it made a complicated process approachable and memorable.

Making Water Law Understandable

Water law can be a tough topic for anyone, much less elementary school students. The water law station focused on prior appropriation, showing how water in a creek is allocated and why seniority matters when flows are limited.

The station was led with support from the St. Vrain and Left Hand Water Conservancy District and the Northern Colorado Water Conservancy District. The goal was simple: make the structure behind water rights understandable without making it boring.

That is important because water law is not abstract when streamflows are low. It determines who can divert, who must curtail, how replacement water is delivered, and why exchanges like the one discussed by the board can be so valuable.

Art, Culture, and Community

WaterFair included 12 partner organizations, an Azteca ceremony and water blessing to open the event, and a marimba ensemble during the fair. The Keep It Clean Partnership displayed youth art submitted from across Boulder County.

One highlight was a riparian art sculpture garden made from five-gallon water jugs. The jugs were used to represent the amount of water used per person each day, then transformed into animals and habitat elements. The sculptures included fish, birds, a turtle, and a memorable beaver, showing exactly why creative work belongs in public water education.

The event also closed with a giant St. Vrain watershed map extended all the way to the ocean. That visual connection matters. Water begins locally in the mountains, moves through the St. Vrain Basin, joins larger river systems, and is part of something much bigger than any one community.

Measuring What People Learn

WaterFair does more than count attendance. It measures educational outcomes through pre-event and post-event questions, demographic information, and participant passports completed at each station.

Questions this year included where St. Vrain Creek goes after it leaves Longmont and which fixture inside a home uses the most water. The results showed stronger understanding after the event.

Participants also identified conservation resources relevant to their lives. The event highlighted that toilets are among the largest indoor water users and that city rebate programs can help residents make conservation upgrades. It also reinforced everyday actions that protect clean rivers and streams.

The fair’s short-term objectives include increasing knowledge of:

• Longmont’s water sources
• Water conservation behavior
• Local water distribution and treatment systems
• Water law and prior appropriation
• Cultural awareness and connection
• Local watershed recreation and stewardship

Work is also underway to secure additional grant funding so WaterFair can continue growing and potentially expand into a winter event.

Conservation, Code Updates, and Future Water Board Topics

The board discussed several continuing policy and planning items.

Longmont has already updated its landscape code to prohibit nonfunctional turf in new development and redevelopment, including rights-of-way. The city has also updated its code related to fines for water-related violations, bringing local enforcement authority and fine structures closer to state requirements.

At this point, staff have not needed to assess fines because people have been responsive when issues are identified. Staff are also continuing to consider water conservation work, irrigation practices, water use, leak maintenance, and related code questions. No additional code package is currently scheduled for City Council review.

Future Water Advisory Board discussions are expected to include:

• Ralph Price water rights
• The Beckwith diversion structure
• Updates following a meeting with the State Engineer’s Office
• Watershed Center work beyond forest health, including stream restoration and fish passage projects
• Water rate structure review and future rate adjustment cycles

Longmont’s Position During Regional Voluntary Restrictions

The board also noted recent regional reporting that many of Colorado’s largest water providers are operating under voluntary water restrictions. Longmont was not among the providers identified as needing those restrictions.

That does not mean water is abundant. Creek flows are low, water calls are active, and drought conditions are real. It means Longmont’s planning, storage, supply portfolio, conservation work, and operational flexibility have created room to respond without immediately imposing restrictions.

That is the value of long-range water planning. It is not about waiting for a perfect year. It is about having enough tools to manage an imperfect one.

Frequently Asked Questions

What is the proposed Longmont water rights exchange?

The proposal would exchange approximately 148.8 acre-feet of Colorado-Big Thompson water from the St. Vrain and Left Hand Water Conservancy District for fully consumable replacement water released by Longmont to support the district’s augmentation plan.

Why does the augmentation program need replacement water?

The program replaces water depleted by small wells, residences, cabins, irrigation pumps, farms, and certain commercial uses so those uses do not injure senior water rights when they are out of priority.

How long would the proposed agreement last?

The proposed intergovernmental agreement would be limited to one year or less and would not automatically renew.

How full are Longmont’s reservoirs?

At the time of the meeting, Union Reservoir was 56.9% full with about 7,264 acre-feet, while Button Rock Reservoir was 99.18% full with about 16,175 acre-feet.

What was the focus of WaterFair 2026?

The 2026 event focused on where water goes after it is used, following its journey from homes through stormwater and wastewater systems, into creeks and watersheds, and through the water law and agricultural systems that shape its use.