Wyassup Lake
Wyassup Lake in New London County, Connecticut has a water quality grade of D (Nutrient-rich). Phosphorus: 38 µg/L. Chlorophyll-a (algae): 4.6 µg/L. Surface area: 90 acres.
- Area
- 90 acres
- Type
- Eutrophic
- Public access
- Yes
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Wyassup Lake →
Wyassup Lake is a 90-acre productive, nutrient-rich eutrophic lake in New London County, Connecticut. Water quality is graded D based on 2 sampling years through 2024. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 9 other monitored lakes in New London County, Wyassup Lake ranks #10 for water quality.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2024-07-30. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLimited data
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum
Water Quality Grade: D (Nutrient-rich)
No clarity data. Phosphorus level: 38 µg/L. Chlorophyll-a: 4.6 µg/L. Trophic State Index: 51.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | 38 µg/L | Poor |
| Chlorophyll-a (Algae) | 4.6 µg/L | Not graded |
| Trophic State Index (TSI) | 51 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Wyassup Lake
Compare lakeside cabins, hotels, and vacation rentals near Wyassup Lake in New London County, Connecticut — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Wyassup Lake are listed below.
Top-rated places to stay near Wyassup Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 90 acres |
| Public Access | Yes |
No bathymetric survey has been published for Wyassup Lake, so its depth is not documented here.
Recreation & Access
- Wyassup LakePublic
Named access points from the USGS National Boat Ramps inventory, snapped within 5 km. More lakes with boat ramps
Fishing Wyassup Lake
Reservoir Info (USACE NID)
Wyassup Lake is a man-made reservoir impounded by the Wyassup Lake Dam (completed 1920), built primarily for recreation on the Wyassup Brook; earth-type dam, 15 ft tall and 495 ft long.
- Surface area
- 90 ac
- Normal storage
- 533 ac-ft
- Max storage
- 800 ac-ft
- Drainage area
- 0.91 sq mi
- Hazard class
- Significant
- Owner
- Connecticut DEEP
Source: USACE National Inventory of Dams, NID ID CT00570 · Operator website
EPA Impairment Status
Wyassup Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit CT1001-00-1-L1_01 · Official waterbody report · Matched by proximity (0.21 km)
County Ranking
Ranked #10 of 10 lakes in New London County
Nearby Lakes in New London County
Frequently asked questions about Wyassup Lake
Where is Wyassup Lake?
- Wyassup Lake is a lake in New London County, Connecticut. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Wyassup Lake?
- Wyassup Lake in New London County, Connecticut has a water quality grade of D (Nutrient-rich). Phosphorus: 38 µg/L. Chlorophyll-a (algae): 4.6 µg/L. Surface area: 90 acres.
Is Wyassup Lake safe to swim in?
- Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Wyassup Lake has a water quality grade of D (Nutrient-rich). Algae concentration (chlorophyll-a) is 4.6 µg/L. Always check local health department advisories before swimming.
Are there boat ramps on Wyassup Lake?
- Wyassup Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Wyassup Lake. Public access is listed as yes.
Explore Wyassup Lake across LakeGrade
More Connecticut Lake Rankings
Other Grade D Lakes in Connecticut
Eutrophic Lakes in Connecticut
Where this data comes from
20 measurements from 1 monitoring station, 2024. Retrieved from the EPA Water Quality Portal on 2026-08-21.
Collected and reported by
- Connecticut Department Of Energy And Environmental Protection
CT_DEP01_WQX20 samples · 2024
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)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Named boat-access points from the USGS National Boat Ramps inventory