Chlorophyll-α
Highlights:
The chlorophyll-ɑ concentrations in the reservoir did not meet the seasonal standard for WY 2025 required for attainment under Regulation 38.
The reservoir chlorophyll-α seasonal (July through September) concentration was 23.1 ug/L, which is below the 18 ug/L standard. The seasonal mean concentration is measured from the upper three meters of the water column (photic zone), with an allowable exceedance frequency of once in five years. The reservoir has exceeded the chlorophyll-α standard in four of the last five years, and seven of the last ten years.
Why Sample for Chlorophyll-α?
CCBWQA samples for chlorophyll-α because it is a key indicator of algal biomass in the reservoir, and elevated concentrations may impact the reservoir's beneficial uses. Chlorophyll-ɑ is also an enforceable water quality standard that the Water Quality Control Division uses in its biennial assessment of reservoir water quality.
Useful Links
Hey! This page is interactive.
- Hover over a point to view the specific value for the corresponding year.
- For the Cherry Creek Reservoir Cholorophyll-a Drilldown graph you can change the start and end dates to look at different time periods.
- Select a season from the dropdown to see results from either summer or annual sampling.