Lake Waramaug
Litchfield County, Connecticut658 acresView mapDirections
CT DEEP publishes the water-quality measurements for Lake Waramaug. Here is what has been measured.
- Eutrophic
- Impaired · Algal growth
- Limited data
Lake Waramaug in Litchfield County, Connecticut has water-quality measurements published by CT DEEP, shown here as reported. Phosphorus: 23 µg/L. Chlorophyll-a (algae): 10.9 µg/L. Surface area: 658 acres.
Lake Waramaug is a 658-acre productive, nutrient-rich eutrophic lake in Litchfield County, Connecticut. Compared to the 11 other monitored lakes in Litchfield County, Lake Waramaug ranks #9 for water quality.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2023-08-03. Methodology: how these readings are compared.
Swimming conditions
Readings onlyRecreation use not supported
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Lake Waramaug is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Lake Waramaug is safe to swim in today is a call for the Connecticut Department of Energy and Environmental Protection and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Lake Waramaug
These are the measurements CT DEEP publishes for Lake Waramaug, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data. Phosphorus 23 µg/L. Chlorophyll-a 10.9 µg/L. TSI 52.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | No reading How deep a black-and-white disk stays visible from the surface. Higher is clearer. | |
| Total phosphorus | 23µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 10.9µg/L | Measured, not scored The green pigment in algae — a direct measure of how much algae is in the water. |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 52 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Lake Waramaug
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
658 acres
No bathymetric survey has been published for Lake Waramaug, so its depth is not documented here.
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Fishing Lake Waramaug
Reservoir Info (USACE NID)
Lake Waramaug is a man-made reservoir impounded by the Lake Waramaug Dam, built primarily for recreation on the East Aspetuck River; masonry-type dam, 3 ft tall and 50 ft long.
- Surface area
- 658 ac
- Normal storage
- 1,974 ac-ft
- Max storage
- 3,290 ac-ft
- Drainage area
- 14.4 sq mi
- Hazard class
- Significant
- Owner
- Town of Washington
Source: USACE National Inventory of Dams, NID ID CT01650 · Operator website
EPA Impairment Status
Lake Waramaug is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Recreation.
Source: EPA ATTAINS assessment unit CT6502-00-1-L2_01 · Official waterbody report
Nearby Lakes in Litchfield County
Frequently asked questions about Lake Waramaug
Where is Lake Waramaug?
- Lake Waramaug is a lake in Litchfield County, Connecticut. Its water-quality measurements are published by CT DEEP and shown on this page as reported.
What is the water quality of Lake Waramaug?
- Lake Waramaug in Litchfield County, Connecticut has water-quality measurements published by CT DEEP, shown here as reported. Phosphorus: 23 µg/L. Chlorophyll-a (algae): 10.9 µg/L. Surface area: 658 acres.
Is Lake Waramaug safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Lake Waramaug is listed impaired under Clean Water Act §303(d) (IR 5) for algal growth, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Explore Lake Waramaug across LakeQuality
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Where this data comes from
10 measurements from 1 monitoring station, 2023. Retrieved from the EPA Water Quality Portal on 2026-08-21.
Collected and reported by
- Connecticut Department Of Energy And Environmental Protection
CT_DEP01_WQX10 samples · 2023
Analytical methods
- Total Phosphorus After Block Digestion
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- Nitrate-Nitrite Nitrogen by Colorimetry
- Turbidity by Nephelometry
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database