Nutrient Project

Northern Water initiated the Nutrient Project in 2005 to comprehensively assess water quality in the C-BT Project. The Nutrient Project includes the Three Lakes Nutrient Study and the Horsetooth Water Quality Study. The Nutrient Project’s objectives:

  • Identify nutrient-related water quality issues
  • Analyze nutrient-related water quality problems and causes
  • Recommend feasible options to improve nutrient-related C-BT Project water quality
The Nutrient Project has three phases:
  • Phase 1 Scoping: Develop a consensus-based scope of study identifying project goals and objectives, water quality issues requiring assessment and how to determine the causes of nutrient-related problems
  • Phase 2 Studies and Results: Fund and carry out Phase 1 studies, synthesize the information gathered, analyze cause/effect relationships and identify the causes of nutrient-related problems
  • Phase 3 Recommendations: Identify key causes of nutrient-related problems that management strategies could effectively and efficiently address (implement feasible options after Phase 3 is complete)
Phase 1 Completed in 2005, the Phase 1 Final Report includes these recommendations:
  • Assess nutrient loading in Lake Granby, Shadow Mountain Reservoir and Grand Lake 
  • Develop mitigation strategies and determine the causes of low dissolved oxygen levels in Horsetooth Reservoir

These recommendations will be addressed in Phase II in the Three Lakes Nutrient Study and the Horsetooth Water Quality Study.

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Three Lakes Nutrient Study
Over the years, algae blooms in Shadow Mountain
Reservoir and Grand Lake have become of increasing
concern for homeowners in the area, Grand County
officials, State and Federal agencies but also for East
Slope water users whose drinking water supply originates
there. The study objectives are to characterize nutrient
loading, identify nutrient sources and develop mitigation
strategies to decrease nutrient loading.

Horsetooth Water Quality Study
In 2006, Horsetooth was listed as impaired for dissolved
oxygen by the Water Quality Control Commission. Ever
since, Northern Water, municipal water users that take
water directly out of Horsetooth Reservoir and the
Colorado Division of Wildlife have been working on
understanding the causes of those oxygen depletions and
assessing if and to what the extent aquatic life was being
impacted. Intensive data collection efforts were carried out
in summer 2009 and a water quality model was developed
to help with this assessment.

Contact Esther Vincent, Water Quality Manager
at (970) 622-2356 or