Great Gorge Lake
Sussex County, New Jersey23 acresView mapDirections
NJDEP publishes the water-quality measurements for Great Gorge Lake. Here is what has been measured.
- Mesotrophic
- Impaired · Nutrients (phosphorus, nitrogen)
- Limited data
Great Gorge Lake in Sussex County, New Jersey has water-quality measurements published by NJDEP, shown here as reported. Water clarity: 12.3 ft visibility. Phosphorus: 11.1 µg/L. Chlorophyll-a (algae): 3.7 µg/L. Surface area: 23 acres.
Great Gorge Lake is a 23-acre mesotrophic lake in Sussex County, New Jersey. Compared to the 17 other monitored lakes in Sussex County, Great Gorge Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2024-07-29. Methodology: how these readings are compared.
What Great Gorge Lake is good for
From access and monitoring records, not editorial picks.
- Clear water12.3 ft of visibility
Swimming conditions
Readings onlyBacteria advisory
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. Great Gorge Lake is listed impaired under Clean Water Act §303(d) (IR 5) for nutrients (phosphorus, nitrogen), pathogens (E. coli, fecal), pH / acidity. Check local advisories before you swim.
Whether Great Gorge Lake is safe to swim in today is a call for the New Jersey Department of Environmental Protection and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Great Gorge Lake
These are the measurements NJDEP publishes for Great Gorge Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 12.3 ft. Phosphorus 11.1 µg/L. Chlorophyll-a 3.7 µg/L. TSI 41.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 12.3ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 11.1µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 3.7µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 41 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Great Gorge Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
23 acres
No bathymetric survey has been published for Great Gorge Lake, so its depth is not documented here.
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Stays near Great Gorge Lake
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Fishing Great Gorge Lake
Reservoir Info (USACE NID)
Great Gorge Lake is a man-made reservoir impounded by the Great Gorge Dam (completed 1971), built primarily for water supply on the Black River-TR; earth-type dam, 28 ft tall and 160 ft long.
- Surface area
- 23 ac
- Normal storage
- 280 ac-ft
- Max storage
- 290 ac-ft
- Drainage area
- 0.25 sq mi
- Hazard class
- High
- Owner
- Mountain Creek Resort
Source: USACE National Inventory of Dams, NID ID NJ00661 · Operator website
EPA Impairment Status
Great Gorge Lake 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: Aquatic life, Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit NJ02020007040010-01 · Official waterbody report
Nearby Lakes in Sussex County
Frequently asked questions about Great Gorge Lake
Where is Great Gorge Lake?
- Great Gorge Lake is a lake in Sussex County, New Jersey. Its water-quality measurements are published by NJDEP and shown on this page as reported.
What is the water quality of Great Gorge Lake?
- Great Gorge Lake in Sussex County, New Jersey has water-quality measurements published by NJDEP, shown here as reported. Water clarity: 12.3 ft visibility. Phosphorus: 11.1 µg/L. Chlorophyll-a (algae): 3.7 µg/L. Surface area: 23 acres.
Is Great Gorge Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Great Gorge Lake is listed impaired under Clean Water Act §303(d) (IR 5) for nutrients (phosphorus, nitrogen), pathogens (E. coli, fecal), pH / acidity. Check local advisories before you swim.
Explore Great Gorge Lake across LakeQuality
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Where this data comes from
19 measurements from 1 monitoring station, 2021–2024. Retrieved from the EPA Water Quality Portal on 2026-08-21.
Collected and reported by
- NJDEP Bureau of Freshwater and Biological Monitoring
NJDEP_BFBM19 samples · 2021–2024
Analytical methods
- Phosphorus by Colorimetry
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- 2120 B ~ Color in Water by Visual Comparison
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