Where Does Longmont Get Its Water?

The City of Longmont’s drinking water is all surface water that comes from streams, lakes, and reservoirs that are fed by snowmelt and rainfall in the St. Vrain Creek watershed and the Colorado and Fraser Rivers on the west slope.

The North St. Vrain Creek watershed stores water in the Ralph Price Reservoir while the South St. Vrain Creek watershed stores water in Burch Lake. The North and South forks combine to form the St. Vrain Creek near the town of Lyons. From there, the Highland and the Palmerton Ditches are used to carry water from the St. Vrain Creek to our treatment centers.

Water from the Colorado and Fraser Rivers in Grand County is delivered to Longmont via the Colorado-Big Thompson (C-BT) project, operated by the Northern Colorado Water Conservancy District. Water from reservoirs in Grand County flows through the Adams Tunnel and is delivered to Longmont through Carter Lake via the St. Vrain Supply Canal and Southern Water Supply Pipeline.

History of Longmont’s Water Utilities

The first settlement in the present-day Longmont area was a trading fort built by Ceran St. Vrain and the Brent brothers in 1838. Settlers began to set up residences along the St. Vrain River, using stream water for their domestic needs. As the colony grew, a few individuals went into business hauling water from the streams which customers stored in large barrels or cisterns. A town pump was located in the center of town at the corner of 4th and Main Streets. On September 8, 1879, the 300 block of Main Street caught fire and was completely destroyed. The only water for fighting the fire came from the town pump and a bucket brigade that formed from the St. Vrain Creek. The fire led to the formation of the first fire fighting company in 1880. The fire of 1879 and the recognized need for a clean water supply were the impetus for developing a water system. On April 1, 1882, the Longmont taxpayers voted a $70,000 bond to build the first pressurized waterworks system.

Water Efficiency Plan

Longmont is dedicated to providing safe, reliable water while conserving resources. For nearly 30 years, the city has focused on using water wisely to ensure there’s enough for everyone, now and in the future. This updated plan builds on past efforts and meets state requirements to reduce water use and be ready for changes in the climate.

The City of Longmont’s Water Conservation Program is seeking your input on the latest update to our efficiency plan! This is a great opportunity for you to share your thoughts and help shape our conservation efforts for the next seven years.

Your feedback is crucial as we strive to create effective programs that benefit our community and conserve our precious water resources. We encourage all residents to participate and make their voices heard.

How to Participate:

• Review the full updated efficiency plan
• Review an executive summary of the plan in English
• Revise un resumen ejecutivo del plan en español
• Take the water efficiency plan survey

Together, we can make a positive impact on Longmont’s water future! Thank you for your involvement.

Water Supply and Drought Management Plan

Longmont Drought Supply Response Level: Sustainable Conservation Level

Longmont is currently at the sustainable conservation level. At the sustainable conservation level the City will continue to implement Best Management Practices to conserve the water resources of the City. To learn how you can save water, visit the Water Conservation pages.

Learn more about Colorado’s drought status.

In an ongoing effort to inform residents and City Council about Longmont’s projected available water supply and demand, staff first began preparing a formalized Water Supply & Drought Management Plan during the drought of 2002. This plan has been annually reviewed and adopted by City Council since that time.

Read the current City of Longmont Water Supply and Drought Management Plan