DEEP: Water Monitoring Data Availability

Water Monitoring Data
The CT DEEP Water Monitoring Program collects a large volume of data, statewide, each year.  It is the goal of the CT DEEP Water Monitoring Program to make all data available to the public.  Data that have gone through the Program's Quality Assurance and Quality Control review process are made available through a variety of online sources. 
The following is a list of data portals and websites from which Connecticut water quality data can be accessed.
General Water Quality Data:
  • EPA Water Quality Portal (WQP)
    The Water Quality Portal (WQP) is a cooperative service sponsored by the United States Geological Survey, the Environmental Protection Agency, and the National Water Quality Monitoring Council. It serves data collected by over 400 state, federal, tribal, and local agencies.
    • The WQP contains sample locations, physical/chemical, biological, habitat and metric results.
    • The WQP is periodically updated with CT DEEP Water Monitoring and Assessment Program data. An ongoing effort is underway to populate the WQP with current and historical program data
River/Stream Data:
  • The CT DEEP Fish (and Macroinvertebrate) Community Data Viewer
    All inland freshwater fish community and benthic macroinvertebrate community data collected by either the CT DEEP Water Monitoring Program or the CT DEEP Inland Fisheries Division to-date is available for viewing and download online through this Data Viewer.  Users can search by town, waterbody, fish species, or macroinvertebrate family. Fish and macroinvertebrate counts are available for over 2,270 sample sites across Connecticut. Data can be exported as a .csv file by town. 
  • Riffle Bioassessment by Volunteers (RBV) Story Map
    RBV is a volunteer monitoring program administered by the CT DEEP Monitoring and Assessment Program.  Volunteers collect benthic macroinvertebrate taxa from riffle habitat in wadeable streams and rivers.  Final data includes a taxa list for each site monitored and a count of 'most wanted' or RBV Program specific water quality sensitive macroinvertebrate types. RBV data is a useful tool for screening for excellent water quality, or identification of Connecticut's Healthy Watersheds. All data collected to-date can be viewed by exploring the RBV Program online Story Map.
  • Spatial Hydro-Ecological Decision System (SHEDS) Stream Temperature Database
    The SHEDS temperature database stores regional stream temperature data across multiple organizations and state agencies in the Northeastern U.S. Users can view stream temperature monitoring locations in Connecticut, including stations monitored by CT DEEP Water Monitoring Program, CT DEEP Inland Fisheries Division, and volunteer groups throughout the state.  (Enter "CT" in the agency search filter to view only Connecticut data.)  Using the Database interface, the user can select and export a georeferenced station list as well as corresponding stream temperature data for each station.  Data are presented as hourly Celsius readings. Selected files are emailed to the user as .csv files.    
  • USGS StreamStats
    StreamStats is a web-based Geographic Information System provided by the United States Geological Survey (USGS) that allows users to obtain streamflow statistics, drainage basin characteristics, and other stream-related information. 
Lake and Pond Data:
  • Lake Bathymetry Maps
    The link above provides a list of available bathymetry maps for Connecticut lakes and ponds.  The user can search by water body name and corresponding town(s) and then download either a simple bathymetry line map or a map of lake bathymetry overlain on aerial imagery.  Downloads are available in .pdf format.
  • Statewide Lake and Large River Electrofishing Survey Results
    The survey results and details are downloadable as a report in .pdf document format. The report contains results for all standard night boat electrofishing samples conducted by the CT DEEP Inland Fisheries Division from the 1980s to present. Catches for each fish species are expressed as the number of fish caught per hour of electrofishing (catch/hr). Catch/hr is presented for fish larger than two different size cutoffs: 1) “Stock size” – approximately the smallest size typically caught by anglers, and 2) “Quality Size” - the size at which most anglers begin to consider the fish a “good catch.”
Long Island Sound Data:
  • Long Island Sound Integrated Coastal Observing System 
    The LISICOS website provides access to a wide variety of historical and real-time data, including water quality data, collected from Long Island Sound.
  • Summer Hypoxia Maps (1991-Current)
    These maps depict the extent of low dissolved oxygen in Long Island Sound for bi-weekly surveys conducted by the DEEP Long Island Sound Water Quality Monitoring Program from June to September. The user can select to view maps by year and then by survey period. Maps can be downloaded as .pdf documents.
  • Water Temperature Maps
    The user can select a sampling period (July through August) to view graphs showing the corresponding temperature gradient trends over the last 17 years in the west-central Sound during that time period.  Graphs are available as .pdf downloads.
Further Information
For questions or additional information please contact:
Chris Bellucci
Monitoring Program Supervisor
Bureau of Water Protection and Land Reuse
Connecticut Department of Energy and Environmental Protection
79 Elm Street, Hartford CT 06106
Content last updated May 2017