Temperature is an important aspect of water quality. The body temperature of most stream organisms is the same as the surrounding water, and each species has a range of temperatures that it can tolerate. Colder water also holds more oxygen than warm water, a vital matter for oxygen-hungry species like trout. Thus water temperature helps determine which species thrive in a given reach of stream.

Are stream temperatures in the Farmington River watershed suitable for trout? Is the temperature of our streams gradually rising as we experience climate change? Are other changes in streams related to changes in temperature? To answer these and other questions, FRWA does stream temperature monitoring in partnership with CT DEEP and US EPA.

Water temperature is monitored at several locations in the watershed with Onset HOBO data loggers. We currently have 18 deployed temperature loggers throughout the upper and lower Farmington River Watershed. These are automatic recording devices that can be placed in a stream bottom for weeks or months until they are retrieved for a data download. HOBOs are swapped in the spring and the fall, which has its challenges—high flows and the shifting rocks on the streambed can make it difficult or impossible to find a HOBO again.  Even curious stream-walkers may remove one. Despite occasional losses, the rescued HOBOs are a valuable source of long-term information about stream temperatures.