Upstream vs. Downstream Temperature
Stream temperature is one of the water quality parameters that we measure. Measuring stream temperature is measuring the amount of heat energy that the water contains. A stream’s temperature is important for assessing aquatic habitats. Many aquatic species need a specific range of temperature in order to live. Stream temperature is changes as one travels up or downstream due riparian shading, geographic area, air temperature, source of water, etc. There is a general trend that upstream temperature is cooler than downstream temperature. Here we look at a few watersheds throughout the state of Utah that demonstrate this trend. Utah water watch volunteer collected the data used to create these graphs.
Castle Creek: Below is an image showing the difference in elevation to be about 3150 feet between sites. The difference in stream temperature between the upstream and downstream sites on average for the year 2015 is about 6.7°C.
This graph shows the stream temperature recordings and trend lines during the year 2015 for Castle Creek.
Weber River Watershed: Below is an image showing the difference in elevation between sites on the lower portion of the Weber River and sites on McLeod Creek to be about 2360 feet. The difference in stream temperature for these sites in the year 2015 is on average about 3.4°C.
This graph shows the stream temperature recordings and trend lines for the lower sites on the Weber River and the McLeod Sites for the year 2015.
Utah Watersheds:Throughout the state, we see the same same trend. Click on a watershed to see figures showing differences in stream temperature between upstream and downstream sites.
Red dots indicate downstream sites, and blue dots indicate upstream sites. Sites may be on different streams, but the streams are connected and can therefore be considered as upstream and downstream sites.