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What impact will the Thornton Water Project have on river flows in the Poudre River?

The Thornton Water Project does not include new diversions from the Poudre River. The water rights that Thornton has ownership in have been diverted from the same location on the Poudre River for over 130 years. Thornton’s Water Court Decree, which was affirmed by the Colorado Supreme Court, requires Thornton to take specific actions to protect the Poudre River, shareholders in the Water Supply and Storage Company, and other water users on the Poudre River.

ConstructionProperty Owners

Will Thornton restore impacted properties to pre-construction conditions?

Yes. In consultation with each landowner, the construction zone will be restored to the prior condition of the property, including the restoration of landscaping, fencing and access roads that do not interfere with the operation of the pipeline.

Property Owners

Will Thornton compensate property owners for easements to construct the buried pipeline?

Yes. Thornton’s acquisition process provides landowners with just compensation and follows the rules and regulations required for easement acquisition.


Why can’t Thornton use the Poudre River to deliver its water?

As a municipal water supplier, Thornton is charged with providing its constituents with a safe drinking water supply that protects human health. The water Thornton receives through its partial ownership in the Water Supply and Storage Company has been diverted from the Poudre River eight miles upstream from the city of Fort Collins since the 1880s. Consistent with Thornton’s Water Court Decree as affirmed by the Colorado Supreme Court, the TWP will not change that operation. Water quality in the Poudre River degrades substantially below this diversion point as the river collects storm water runoff, agricultural runoff, and discharges from multiple wastewater treatment plants. While it is possible to treat a degraded source of supply with advanced treatment technologies, this practice presents a higher risk to human health and safety. In addition, these technologies use substantially more energy and chemicals to produce water that meets Safe Drinking Water Act Standards, and consequently leave a much larger environmental footprint than conventional treatment. This is why Thornton, like other water providers, such as the city of Fort Collins, Northern Water, the city of Greeley and the Tri-Districts, choose high quality sources of supply.


What will the pipeline look like? What will I see? Will there be above ground structures?

The 42-inch welded steel pipeline will be buried, but you might see access hatches, manhole lids, and vent pipes. There will be a number of discharge structures located along the pipeline for pipeline draining. Pipeline markers and test stations for corrosion protection will be above ground.


Where does the water for the project come from?

The water comes from the Cache la Poudre River and is diverted eight miles upstream from Fort Collins into reservoirs owned by the Water Supply and Storage Company.


Where can I find the Thornton Northern Water Supply Project decree?

To view the decree, open the Findings of Fact, Conclusions of Law, Judgement and Decree on Remand.

ConstructionGeneralProperty Owners

Will Thornton maintain access to impacted properties during construction?

Yes. Access to properties along public streets and roads will be maintained during construction. The access might not be at the same location currently used, but access will be maintained and restored to its original location as quickly as possible.


Why is Thornton starting now if the pipeline isn’t needed until 2028?

We want to continue to be a good community neighbor and collaborate with stakeholders early in the process. In addition, it takes many years to perform the necessary studies and designs, acquire the necessary approvals and easements, and construct a 70-mile-long pipeline.


Will the Thornton Water Project serve other communities?

Legally, our water rights can only be used to supply our water customers. However, we are open to partnering with other communities in northern Colorado to share infrastructure.


Why can’t Thornton just increase conservation and efficiency efforts to provide additional water?

Thornton has one of the lowest per-person water usage rates in the state, and will continue to be a leader in water conservation, but conservation alone isn’t sufficient to meet the city’s ongoing and future water supply needs.


What permits will Thornton need?

We estimate that over 600 permits or approvals will be needed. We have initiated the land use permit processes in Weld and Larimer Counties, and have contacted the cities, towns and districts along the proposed pipeline route to understand their permitting requirements and processes. We plan to meet or exceed all permit requirements for the Project. We have consulted with the Army Corps of Engineers regarding Project construction, and will continue to do so as the Project progresses.

ConstructionProperty Owners

Will the pipeline cross my property?

Most of the locations for the pipeline have been determined; to view the proposed pipeline alignment, view the Thornton Water Project Location Map.



Will the pipeline be buried?

Yes, the pipeline will be buried with some appurtenances and access points above ground.


What is the Thornton Water Project timeline?

Thornton’s target is to deliver this additional water supply to water customers in 2027.

View the Thornton Water Project Timeline



What is the Thornton Water Project?

The Thornton Water Project is a pipeline through Adams, Larimer and Weld Counties that will bring water purchased in the 1980s to Thornton customers.