Water Quality

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, 2019 Northern Water submitted its 401 application regarding NISP to the Colorado Water Quality Control Division. On Jan. 28, 2020, the Water Quality Control Division of the Colorado Department of Public Health and Environment issued NISP its Colorado 401 Water Quality Certification.

Northern Water's approval of the 401 certification 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 

Since 2015, Northern Water 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