Volunteer Stream Temperature Monitoring (VSTeM) Network

Community-Science Based Water Quality Monitoring

The Volunteer Stream Temperature Monitoring (VSTeM) Network is a statewide volunteer (i.e., 'citizen science' or 'community science') water quality monitoring program coordinated by DEEP as part of the Volunteer Water Monitoring Program.  Participants in the V-STeM Network are trained to monitoring the water temperature waterbodies in their town or watershed.  Monitoring typically occurs year-round, with the majority of field activity occurring in the Spring (April-May) and fall (September-October). 

The CT Volunteer Water Monitoring Program Online Map Application shows where in Connecticut volunteers have previously collected water quality data, including stream temperature data (select the "Rivers: VSTeM Network" tab). Blue areas indicate watersheds that have been identified as a cold water supporting drainage basin based upon either stream temperature data or fish community data

The data collected by VSTeM Network volunteers are used to inform CT DEEP water quality assessments, help develop state water temperature standards, identify cold water habitat, and determine the impact of nonpoint source pollution mitigation projects. 


Program Materials

Field Materials

Data Availability

Hourly water temperature data collected by VSTeM volunteers are upload to the Spatial Hydro-Ecological Decision System (SHEDS) Stream Temperature Database.  The Stream Temperature Database allows users to view an interactive map of all past and current monitoring stations in Connecticut, explore graphs of stream temperature collected by volunteers, and download station information and the corresponding data.

If volunteers are able to successfully monitor a site from June through August, the data for that year are used to generate a water temperature classification (i.e., cold, cool, or warm) for the station.  These classifications are available for download from the Water Quality Portal. (Download 'Site data only' to view monitoring locations.  Download 'Sampling Activity' to view results for each station.)

Frequently Asked Questions

Where can I used VSTeM to monitor?

Volunteers can monitor water temperature in any streams or rivers that flow year round.  Groups monitor for a variety of reasons including, but not limited to, assisting DEEP with expanding statewide coverage, identification of cold water fish habitat, documenting thermal impairments, monitoring the impact of stormwater runoff, and conducting baseline and post-implementation project monitoring to determine the thermal impacts of a given project. 

Volunteers can use the VSTeM Network tab within the CT Volunteer Water Monitoring Program Online Map Application to identify new monitoring locations.  Stream segments that have not yet been monitored, particularly those that are predicted to be cold water, are ideal candidates for new monitoring.  If resources allow, once a cold water site is identified, volunteers are encouraged to continue to monitor that site indefinitely in order to assist the State with tracking long-term temperature trends at cold water sites. Groups are encouraged to contact the Volunteer Water Monitoring Program Coordinator to discuss annual monitoring locations.  

Do volunteers need to have previous experience monitoring streams?

No, no prior monitoring experience is necessary. All new stream temperature monitoring network volunteers are required to complete a training led by the CT DEEP Volunteer Water Monitoring Coordinator.  During training volunteers are taught how to use the monitoring equipment, how to select a field location and install monitoring equipment, how to document their monitoring locations, and how to manage the resulting data.

What equipment is needed to participate? 

VSTeM groups are responsible for purchasing their own equipment and software.  A temperature logger is needed for each site monitored, along with some basic materials for protecting the logger while it is deployed in the stream such as zip ties, PVC tubing, and a cinder block.  In addition, groups will need to purchase a shuttle to connect the logger(s) to a computer and the required software to communicate with the logger.  It is estimated that that the initial startup cost for equipment and software to monitor a single site is about $400, each additional site costs an estimated $150.  The equipment typically can be used to monitor for about five years after purchase.

Related DEEP Pages

For More Information Contact

Volunteer Water Monitoring
CT DEEP Water Monitoring and Assessment Program
79 Elm Street, Hartford, CT 06106


Content last updated August 17, 2023