Crystal Lake
Litchfield County, Connecticut145 acresView mapDirections
CT DEEP publishes the water-quality measurements for Crystal Lake. Here is what has been measured.
- Oligotrophic
- Limited data
Crystal Lake in Litchfield County, Connecticut has water-quality measurements published by CT DEEP, shown here as reported. Phosphorus: 9 µg/L. Chlorophyll-a (algae): 1.4 µg/L. Surface area: 145 acres.
Crystal Lake is a 145-acre cold, clear oligotrophic lake in Litchfield County, Connecticut. Compared to the 11 other monitored lakes in Litchfield County, Crystal Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2022-07-26. Methodology: how these readings are compared.
Swimming conditions
Readings onlyLimited data
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. Check local advisories before you swim.
Whether Crystal Lake 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 Crystal Lake
These are the measurements CT DEEP publishes for Crystal Lake, 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 9 µg/L. Chlorophyll-a 1.4 µg/L. TSI 35.
| 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 | 9µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 1.4µg/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. | 35 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Crystal Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
145 acres
No bathymetric survey has been published for Crystal Lake, so its depth is not documented here.
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Fishing Crystal Lake
Reservoir Info (USACE NID)
Crystal Lake is a man-made reservoir impounded by the Crystal Lake Reservoir Dam (completed 1892), built primarily for water supply on the Sucker Brook; earth-type dam, 13 ft tall and 520 ft long.
- Surface area
- 145 ac
- Normal storage
- 1,680 ac-ft
- Max storage
- 1,680 ac-ft
- Drainage area
- 1.1 sq mi
- Hazard class
- Significant
- Owner
- Town of Winchester
Source: USACE National Inventory of Dams, NID ID CT00104 · Operator website
Nearby Lakes in Litchfield County
Frequently asked questions about Crystal Lake
Where is Crystal Lake?
- Crystal Lake 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 Crystal Lake?
- Crystal Lake in Litchfield County, Connecticut has water-quality measurements published by CT DEEP, shown here as reported. Phosphorus: 9 µg/L. Chlorophyll-a (algae): 1.4 µg/L. Surface area: 145 acres.
Is Crystal Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Explore Crystal Lake across LakeQuality
More lakes in Connecticut
Other Lakes in Connecticut
Oligotrophic Lakes in Connecticut
Where this data comes from
10 measurements from 1 monitoring station, 2022. 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 · 2022
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.