Committing Today to a Better Tomorrow.

Drinking Water Treatment Plant 

Our new state-of-the-industry water treatment plant uses the latest treatment processes. It came online in September 2020. To learn more about the Thornton Water Treatment Plant, watch our Your Water Quality video and read the What It Takes To Treat Your Water Waterblogged.

Safety

Our water quality laboratory provides constant water sampling, monitoring, and testing to closely monitor our water before, during and after the treatment process to make sure it’s always ready to drink and meets stringent state and federal water quality standards. Learn more on the city of Thornton’s water quality page.

Taste & Smell

There are many factors that cause differences in how water tastes and smells. For Thornton, these variations occur because of natural elements in our source water. Learn about the natural taste and smell of water in our blog.

Hardness

A measure of the amount of dissolved calcium and magnesium that occurs naturally in all water, hardness doesn’t mean the water is bad. Our blog tackles the issue of water hardness.

Lead

Lead in drinking water is primarily from materials and components associated with service lines and home plumbing. Thornton does not install lead service lines and elevated lead levels have not been detected in the city. We have the latest information in our Water Quality Report.

Due to the age of Thornton’s water infrastructure, there are no recorded lead service lines in the city of Thornton. Customers can use our Water Service Inspection viewer to locate their address and research the potable water service line materials at their property. A service line can be considered non-lead without further verification if one of the following criteria is met:

1. The service line was installed after the state lead ban of January 31, 1988, or after an earlier local ordinance or regulation banning lead.

2. The service line is four inches or more in diameter.

For more information on your water service line, contact Thornton Utility Operations at 720-977-6500 or visit the city of Thornton water quality page.

PFAS

Across the nation, water utilities are addressing the impact of PFAS on water supplies. Our Thornton water team is proactively taking steps to inform residents; assess levels, scope, and source of contamination; and examine next steps to meet EPA levels. People do not need to stop drinking their water because of the recent PFAS HAL update. Visit the city of Thornton’s PFAS page for more information.

Water Quality Report

This 2026 Annual Water Quality Report provides an overview of the tens of thousands of water quality samples and analyses performed in 2025. Staff members monitor the drinking water from where it starts as snowmelt in the headwaters of the South Platte River basin, throughout the treatment process and distribution system, to where it ends at customers’ taps.

To learn more about water quality in Thornton, read the 2026 Water Quality Report. 

Para obtener más información sobre la calidad del agua en Thornton, lea el informe de calidad del agua 2026.

Sources & Storage

Starting as snow high in the Rocky Mountains, Thornton sources its water from Clear Creek and the South Platte River. Based on our water rights to these sources, we divert it, store it in 19 reservoirs, and treat it to water quality standards to supply drinking water to our customers. Access the City of Thornton water services page here.

Thornton Water Project

The Thornton Water Project is a new pipeline that will provide the water required to meet the future needs of our growing community. The new pipeline is slated for completion in 2027 at the earliest.

Sustainability & Agricultural Stewardship

Did you know our state regulates different types and uses for our water rights, including securing water storage for our city? In the mid-1980s, Thornton purchased farmland in Larimer and Weld counties to shift the water rights from agricultural use to municipal use in Thornton. Those rights will provide Thornton’s supply of water well into the future. For information on Thornton’s land stewardship on our Northern properties, visit the Northern Properties Stewardship webpage.

Water Meter Upgrades

Thornton has been upgrading its household water meters and registers, replacing the current batch with more precise versions that will be compatible with new water reading technology, called Advanced Metering Infrastructure (AMI). Learn more about these upgrades on our Lines, Hydrants and Meters page.

Advanced Metering Infrastructure

The city is replacing 25,000 residential water meters to be compatible with Advanced Metering Infrastructure (AMI) technology. This will enable us to track hourly water usage data instead of monthly. Additional AMI technology will be installed over the next two years to be able to detect water leaks and other issues much sooner. The quicker the city and customers are alerted to leaks, or other high-water issues, the quicker we can address them and prevent water from being wasted. Learn how AMI can detect leaks early on our Lines, Hydrants and Meters page.

Pipeline Rehabilitation

Thornton continuously works on various Capital Improvement Projects including maintaining 625 miles of underground water lines, some 60+ years old. The pipeline rehabilitation program utilizes new technologies to repair deteriorated pipes throughout Thornton’s water distribution system. Locations are identified based on pipe breaks and an annual review of pipe age data. You can see information about different projects throughout the city on the Capital Improvement Projects interactive page under the “Water” tab.

Capital Improvement Program

The Capital Improvement Program (CIP) provides for cost-effective design and construction of capital projects that enhance the quality of life for citizens or result in the reduction of ongoing maintenance costs. We have a five-year CIP plan, which is updated annually. Projects include improvements to transportation, city facilities, trails, and the water, storm sewer, and sanitary sewer systems. Visit our interactive map for information on the Capital Improvement Projects.

Water Efficiency Plan

Thornton’s Water Efficiency Plan establishes long-term water efficiency goals that encourage the efficient use of available water resources. Our objective is to reduce the amount of additional water needed to serve existing and future customers, while maintaining a high-quality urban environment. We implement, monitor, measure and evaluate water-efficiency activities and regularly revise the Water Efficiency Plan to meet these targets.

Review a summary of the 2025-2031 Water Efficiency Plan, here. 

Revise un resumen del Plan de Eficiencia Hídrica 2025-2031, aquí.

Improving Water Efficiency in New Developments

Thornton’s city planners understand the importance of water for our community. New guidelines will ensure we continue to develop our communities responsibly.

Naturally Thornton & Parks

Thornton manages over 140 miles of trails and 2500+ acres of parks and open space for residents to enjoy. Our H2Overhaul for sustainable landscapes is a tiered approach for the future of our open spaces. With low to no maintenance, we allow existing high-water plants and grasses to expire and replace them with native, low-water alternatives. Learn more at Naturally Thornton.

WaterSmart Program

Stay informed about your water account with WaterSmart. Just create a WaterSmart profile and set alerts, get text reminders, track and compare your consumption, find leaks, get personalized tips on ways to save and lots more.  Sign up to access your WaterSmart account.

Water Use Rules

Rebates* & Free Services

To encourage everyone in the community to help us save Thornton’s water supply, we offer many rebate programs, discounts and free services to reward residential and business customers.

* Rebates may be considered taxable income by the IRS. Consult a tax professional for more information.

Drought Plan

Planning for drought means managing supply, demand, and impact, and ensuring the delivery of adequate supply to all water customers. The plan also includes additional steps for reducing water demand and acquiring additional water supplies. Read the drought management plan. For current drought phases and restrictions, please visit our Drought Response page.