Greeley's water starts as pure Rocky Mountain snowmelt and the Water Department uses the latest technologies and most effective practices to further improve the quality of drinking water. Two water treatment plants make the water safe to drink in Greeley. The Bellvue plant is located at the mouth of the Poudre Canyon and runs continually throughout the year. The other plant is located at Boyd Lake in Loveland. The Boyd plant is a seasonal peaking plant, which runs through the lawn watering season and is shut down for maintenance during winter months when there is low water demand.
Bellvue Water Treatment Plant
In 1905, Greeley's 5,000 citizens voted whether to go to the mountains for high quality drinking water. 
Those in favor of the water infrastructure won by a landslide; 97% of the voters approved the measure. It took two years to build the Bellvue Water Treatment Plant. The site was completed in 1907. The other important component in the process was the 36-mile wooden transmission pipeline that conveyed the water from the Bellvue Plant to Greeley. The original plant has been enlarged and upgraded several times before being replaced by conventional filtration in 1946-1947 and was most recently upgraded in 2007. The Bellvue Plant can treat 35 million gallons of water per day and operates 365 days per year to ensure the City is never in short supply of high quality water.
Boyd Lake Water Treatment Plant
The Boyd Lake Treatment Plant provides seasonal drinking water to Greeley water customers. This facility produces 38 million gallons per day. The plant supplements the Bellvue Water Treatment Plant by providing additional water in times of high demand. The plant was built in 1964 and was last upgraded in 2005. The Boyd Lake Plant also serves as back-up for the Bellvue Plant in case of an emergency. The plant's raw water supply comes from both Boyd Lake and Lake Loveland. The treated water from this plant must be pumped to the city's finished water reservoirs.