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LakeQuality

Curlis Lake

F
Grade F — Algae-prone
Algae-prone · #4 of 15 lakes in the county · 2.4 ft clear · Hypereutrophic · 18 acres
Limited DataHypereutrophic

Curlis Lake in Mercer County, New Jersey has a water quality grade of F (Algae-prone). Water clarity: 2.4 ft visibility. Phosphorus: 121 µg/L. Chlorophyll-a (algae): 49.8 µg/L. Surface area: 18 acres.

Clarity
2.4 ft
Area
18 acres
Type
Hypereutrophic

Grade F measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Curlis Lake

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Curlis Lake is a 18-acre highly nutrient-loaded hypereutrophic lake in Mercer County, New Jersey. Water quality is graded F based on 2 sampling years through 2022. Compared to the 14 other monitored lakes in Mercer County, Curlis Lake ranks #4 for water quality.

Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2022-11-07. Grade methodology: LakeGrade methodology.

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Swimming Safety

Grade only

Bacteria advisory

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.

Algae and nutrients are often high — check current advisories before swimming. Skip the water if you see scum or a paint-like bloom

Get alerts for Curlis Lake

Water Quality Grade: F (Algae-prone)

Very murky, less than 2.4 ft of visibility. Phosphorus level: 121 µg/L. Chlorophyll-a: 49.8 µg/L. Trophic State Index: 69.

MetricValueGrade
Water Clarity (Secchi Depth)2.4 ftNot graded
Phosphorus121 µg/LPoor
Chlorophyll-a (Algae)49.8 µg/LPoor
Trophic State Index (TSI)69Hypereutrophic

Very high nutrients, dense algae, poor clarity

Where to stay near Curlis Lake

Compare lakeside cabins, hotels, and vacation rentals near Curlis Lake in Mercer County, New Jersey — 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 Curlis Lake are listed below.

Top-rated places to stay near Curlis Lake

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

Lake Details

CharacteristicValue
Surface Area18 acres

No bathymetric survey has been published for Curlis Lake, so its depth is not documented here.

Fishing Curlis Lake

Reservoir Info (USACE NID)

Curlis Lake is a man-made reservoir impounded by the Stony Brook #4 (Curlis Lake) Dam (completed 1959), built primarily for flood risk reduction on the Stony Brook-TR; earth-type dam, 24 ft tall and 340 ft long.

Surface area
18 ac
Normal storage
100 ac-ft
Max storage
285 ac-ft
Drainage area
1.7 sq mi
Hazard class
Low
Owner
County of Mercer Park Commission

Source: USACE National Inventory of Dams, NID ID NJ00390 · Operator website · Matched by proximity (0.3 km)

EPA Impairment Status

Curlis Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).

Causes of impairment

Pathogens (E. coli, fecal)

Source: EPA ATTAINS assessment unit NJ02030105090040-01 · Official waterbody report · Matched by proximity (1.97 km)

County Ranking

Ranked #4 of 15 lakes in Mercer County

Nearby Lakes in Mercer County

Frequently asked questions about Curlis Lake

Where is Curlis Lake?

Curlis Lake is a lake in Mercer County, New Jersey. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.

What is the water quality grade for Curlis Lake?

Curlis Lake in Mercer County, New Jersey has a water quality grade of F (Algae-prone). Water clarity: 2.4 ft visibility. Phosphorus: 121 µg/L. Chlorophyll-a (algae): 49.8 µg/L. Surface area: 18 acres.

Is Curlis Lake safe to swim in?

Algae and nutrients are often high — check current advisories before swimming. Skip the water if you see scum or a paint-like bloom. Curlis Lake has a water quality grade of F (Algae-prone). Algae concentration (chlorophyll-a) is 49.8 µg/L. Always check local health department advisories before swimming.

Where this data comes from

32 measurements from 2 monitoring stations, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-21.

Collected and reported by

  • NJDEP Bureau of Freshwater and Biological MonitoringNJDEP_BFBM32 samples · 2022

Analytical methods

  • Phosphorus by Colorimetry
  • 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
Monitoring station identifiers (2)

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