How many lakes and reservoirs in Connecticut are tracked here?

12, of which 4 report a current pool-elevation reading. The rest report storage only, or lack a fresh reading and are not published.

Which Connecticut lakes report a %-full figure?

None of Connecticut's lakes in this dataset currently have a source-provided %-full figure — we show the bare level rather than estimate one.

Where does the data come from?

USGS Water Services and USACE CWMS Data, both public domain. See the methodology page for the exact endpoints and update cadence.

Connecticut lake & reservoir water levels

12 lakes tracked · 4 with a current elevation reading · USGS Water Services + USACE CWMS Data

Connecticut has 12 lakes and reservoirs tracked here — 4 with a current elevation reading, from USGS Water Services and USACE CWMS Data. Sort the table by level, storage, %-full, or trend, then open any lake for its full elevation-with-datum, trend sparkline, storage, and source-and-vintage stamp. Figures are provisional readings for reference — not for navigation or safety decisions.

Statewide totals Connecticut · USGS + USACE

Lakes tracked: 12
With elevation reading: 4
With %-full figure: 0

All Connecticut lakes

Every lake tracked in Connecticut. Click a column heading to sort, or filter by name. Elevation lakes are listed before storage-only lakes; a missing figure always shows "not reported," never an estimate.

Filter lakes

Connecticut lakes, elevation lakes first, by name.
		Datum			Trend
Colebrook Dam	698.48	NGVD29	40,566	—	↑Rising
Hancock Brook Dam	461.21	NGVD29	59	—	→Steady
Northfield Brook Dam	502.96	NGVD29	—	—	→Steady
West Thompson Dam	306.41	NGVD29	1,538	—	↑Rising
Black Rock Dam	—	—	3	—	—
East Branch Dam	—	—	0	—	—
Hall Meadow Dam	—	—	87	—	—
Hop Brook Dam	—	—	30	—	—
Mad River Dam	—	—	0	—	—
Mansfield Hollow Dam	—	—	3,394	—	—
Sucker Brook Dam	—	—	0	—	—
Thomaston Dam	—	—	18	—	—

Data: USGS Water Services (waterservices.usgs.gov) and USACE CWMS Data (cwms-data.usace.army.mil), retrieved 2026-07-14. Both public domain (a work of the U.S. Government, 17 U.S.C. §105).

Frequently asked questions

How many lakes and reservoirs in Connecticut are tracked here?: 12, of which 4 report a current pool-elevation reading. The rest report storage only, or lack a fresh reading and are not published.
Which Connecticut lakes report a %-full figure?: None of Connecticut's lakes in this dataset currently have a source-provided %-full figure — we show the bare level rather than estimate one.
Where does the data come from?: USGS Water Services and USACE CWMS Data, both public domain. See the methodology page for the exact endpoints and update cadence.

Explore

Read the methodology behind these figures, or search all lakes nationally from the home page.