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Connecticut Lake Watch

Community-Based Lake and Pond Water Quality Monitoring

Image of a secchi disk being lowered from a boat in order to measure water clarity in a lake.The Connecticut Lake Watch network is a statewide volunteer (i.e., community science) water quality monitoring program coordinated by DEEP as part of the larger Connecticut Volunteer Water Monitoring Program. Connecticut Lake Watch participants are trained to monitor lake/pond water clarity using a secchi disk. Monitoring typically occurs weekly between May and September. In addition, volunteers are trained to identify and report algal blooms that could lead unsafe recreation conditions.

The data collected can be used to guide local lake management efforts, inform CT DEEP water quality assessments, and evaluate trends in lake and water quality statewide over time. 

Not yet a CT Lake Watch participant? Fill out the General Interest Survey to get involved!

Program Materials
Field Materials
Aquatic Invasive Species Information:
Paddlecraft Safety Information:

Training Resources:
Data Submission and Management
Frequently Asked Questions
An individual lowers a secchi disk from the side of a boat to measure lake water clarity.Who can use the Connecticut Lake Watch protocols to monitor?

Any individual can be certified to use the Connecticut Lake Watch protocol to monitor water clarity on Connecticut lakes and ponds. However, individuals who live on or regularly recreate on a particular like are ideal Lake Watch volunteers.

CT DEEP is also interested in partnering with interested lake associations in Connecticut that have an existing water quality monitoring program or associations that would like to establish a new monitoring program.  If you would like to join CT Lake Watch please complete and submit the general interest form.

When do volunteers monitor?

Trained Connecticut Lake Watch volunteers are asked to monitor their designated lake site(s) weekly between May and September. Monitoring ideally will occur during mid-day. Some volunteers choose to continue to monitor secchi depth during October through April, but this is not required.  If it is of interest, volunteers can continue to use the Lake Observer tools to record ice out during the winter months. 

Do volunteers need to have previous experience monitoring lakes?

Prior monitoring experience is not necessary. All new volunteers are required to complete a CT DEEP-led training to review proper field protocols (e.g., secchi disk depth recording and surface water temperature data recording) and data submission guidelines. During initial basic training new volunteers are taught how to take a secchi disk depth reading and how to submit their data to the Lake Observer database. 

Experienced monitors, particularly those who have a history of collaborating with CT DEEP, are eligible to complete an accelerated training that focuses primarily on the use of Lake Observer for data management purposes.

What equipment is needed to participate?

A secchi kit on a dock.Connecticut Lake Watch participants are responsible for purchasing their own equipment. To get started, a waterproof camera and a black-and-white secchi disk and calibrated line are needed, along with basic materials such as a field notebook or clipboard. Secchi disks can vary in cost depending on size and quality but a group should expect to spend anywhere from $50-100 on a disk. A waterproof digital camera typically costs between $100-400 depending on the quality purchased. Well-maintained equipment can be used to monitor a site for many years after purchase.

In addition, since measurements are typically taken at the deepest part of the lake or pond, a boat with a life preserver and anchor is needed. (Power boats are not required; a kayak or canoe can be used on most waterbodies.)

The DEEP Volunteer Water Monitoring Program has several secchi disk kits available for annual loan. To reserve a kit please contact the Volunteer Water Monitoring Coordinator

My lake group already has collected several years of lake data, is DEEP interested in this information?

Yes! CT DEEP is very interested in any available historic lake and pond water quality data. Please contact the Volunteer Water Monitoring Coordinator to discuss further.

A screenshot of the Lake Observer mobile app secchi depth data entry screen.Data Availability

Data collected by Lake Watch volunteers are uploaded directly by volunteers to the Lake Observer Database using either the website submission form ('web app') or a mobile app. 

Once data are uploaded, Lake Observer allows any individual to view and download the data.  To allow for development of lake health report cards and regional trend analysis, water quality data will be shared with the EPA Water Quality Portal and aquatic invasive plant data will be shared with the USGS Nonindigenous Aquatic Species (NAS) database.

If you are interested in exploring Connecticut volunteer lake data, select “Connecticut Lake Watch” from the Lake Observer project drop-down menu and then select “Search” at the bottom of the page. (If you use the data for a project, we would love to know about it!)

Related DEEP Pages
Other Resources


For More Information Contact:

Volunteer Water Monitoring Program Coordinator 

Content last updated September 9, 2021.