Water Quality

Poudre River water quality monitoring


As part of the federal permitting process, a 401 Water Quality Certification – the state's review of the water quality impacts associated with the project – is required before the U.S. Army Corps of Engineers can issue its final approval with a 404 permit and Record of Decision.

On Jan. 31, Northern Water submitted its 401 application regarding NISP to the Colorado Water Quality Control Division.  

This application process includes:
• A preliminary review of the project 
• A 30-day public comment period
• A review of the public comments 
• The state's decision to approve, conditionally approve or deny the certification

The public comment period regarding NISP's 401 certification ended April 22. 

Click here to go to the Colorado Water Quality Control Division's NISP 401 certification page. 

And click here to learn more about the 401 Water Quality Certification application process.

Northern Water's submission of its application comes as part of an ongoing, collaborative process that Northern Water has been engaged in during recent years. Those efforts, among others, have included data collection and monitoring along the Poudre River, water quality and temperature modeling, examining potential NISP-related water quality and temperature impacts, and developing mitigation measures.

A commitment to the health of the Poudre River 

Northern Water since 2015 has collected hundreds of samples each year, investing approximately $450,000 annually into its Poudre River monitoring program.

Long-term and on-going water quality monitoring allows for the identification of changes in water quality spatially and over time. Data are used to assess compliance with federal and state regulations and identify water quality impairments.

Additionally, data provide context in the event of natural disasters like wildfires and floods that can drastically impact watersheds and alter water quality, or in the event of a catastrophic spill or failures that would affect the river system. The data also helps to evaluate possible changes in water quality associated with new water projects such as NISP:

• Existing data are used to support modeling efforts and detailed assessments to understand what affects water quality in the river and to what extent future projects might change water quality

• Data will also serve in the future to evaluate the effectiveness of enhancement and mitigation measures that will be required once new water supply projects are built


Colorado Water Quality Control Division's NISP 401 Certification Page

• 401 Water Quality Certification Application Process

Northern Water's Water Quality Data Retrieval Database  

Northern Water's East Slope Temperature Data 

Cache la Poudre River monitoring brochure 

2019 Cache la Poudre Water Quality Monitoring Program Summary

2019 Cache la Poudre Temperature Monitoring Program Summary

To learn more, contact Curtis Hartenstine, Water Quality Department manager, at (970) 622-2246, or at chartenstine@northernwater.org.