Ecological Health & Function

Flow Regime

CATEGORY: Water Quality

hydrograph indicator

Temperature Indicator

Water temperature can be recorded using a standard water quality meter or a thermometer. The ranges of many aquatic species are limited by temperature, so this parameter is important to measure from a habitat perspective. Shading from the riparian canopy, good hyporheic exchange with local groundwater, and seepage from spring-fed tributaries (in some cases) contribute to lower temperatures that support the cool- and cold-water fish species present in Colorado streams and rivers.

The Scorecard focal segment is located in a transition zone between cold-water and warm-water fisheries, so temperatures are expected to increase naturally in a downstream direction.

Temperature score by Segment

Upper Yampa Segment

Score coming 2025

Elk River
Segment

Score coming 2026

Lower Yampa
Segment

Score coming 2027

Did You Know?

Appropriate water temperatures in Colorado rivers are regulated by the Colorado Department of Public Health and Environment (CDPHE). Temperature tiers for Colorado streams are based on which fish species are expected to be present and the water temperature ranges in which those fish species can survive and thrive.

Above its confluence with Elkhead Creek, the Yampa is classified by CDPHE as “Cold Water Tier 1.” Below its confluence with Elkhead Creek, it is classified as “Warm Water Tier 1.” The Middle Yampa River segment scoring results show that distinction clearly; scores are much lower upstream of Elkhead Creek than downstream because the temperature standards are so different, due to the different needs of the cold-water and warm-water fish species that dominate those segments.

What else goes into the scoring?