Boardwalk Lake
Sussex County, New Jersey777 acresView mapDirections
NJDEP publishes the water-quality measurements for Boardwalk Lake. Here is what has been measured.
- Eutrophic
- Impaired · Impaired biota (cause unknown)
- Limited data
Boardwalk Lake in Sussex County, New Jersey has water-quality measurements published by NJDEP, shown here as reported. Water clarity: 5.2 ft visibility. Phosphorus: 40 µg/L. Surface area: 777 acres.
Boardwalk Lake is a 777-acre productive, nutrient-rich eutrophic lake in Sussex County, New Jersey. Compared to the 17 other monitored lakes in Sussex County, Boardwalk Lake ranks #10 for water quality.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2020-10-28. Methodology: how these readings are compared.
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. Boardwalk Lake is listed impaired under Clean Water Act §303(d) (IR 5) for impaired biota (cause unknown), metals (other than mercury), pathogens (E. coli, fecal), temperature. Check local advisories before you swim.
Whether Boardwalk 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 Boardwalk Lake
These are the measurements NJDEP publishes for Boardwalk Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 5.2 ft. Phosphorus 40 µg/L. TSI 55.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 5.2ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 40µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | No reading 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. | 55 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Boardwalk Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
777 acres
No bathymetric survey has been published for Boardwalk Lake, so its depth is not documented here.
Stays via Stay22
Stays near Boardwalk Lake
Compare lakeside cabins, hotels, and vacation rentals near Boardwalk Lake in Sussex 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 readings cover nutrients and algae, not lodging. Cabins and rentals around Boardwalk Lake are listed below.
Top-rated places to stay near Boardwalk Lake
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Fishing Boardwalk Lake
Reservoir Info (USACE NID)
Boardwalk Lake is a man-made reservoir impounded by the Lake Mohawk Dam (completed 1927), built primarily for recreation on the Wallkill River; earth-type dam, 20 ft tall and 580 ft long.
- Surface area
- 777 ac
- Normal storage
- 8,220 ac-ft
- Max storage
- 14,220 ac-ft
- Drainage area
- 4.3 sq mi
- Hazard class
- High
- Owner
- Lake Mohawk Country Club
Source: USACE National Inventory of Dams, NID ID NJ00017 · Operator website · Matched by proximity (0.2 km)
EPA Impairment Status
Boardwalk 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: Drinking water, Aquatic life, Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit NJ02020007010010-01 · Official waterbody report
Nearby Lakes in Sussex County
Frequently asked questions about Boardwalk Lake
Where is Boardwalk Lake?
- Boardwalk 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 Boardwalk Lake?
- Boardwalk Lake in Sussex County, New Jersey has water-quality measurements published by NJDEP, shown here as reported. Water clarity: 5.2 ft visibility. Phosphorus: 40 µg/L. Surface area: 777 acres.
Is Boardwalk Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Boardwalk Lake is listed impaired under Clean Water Act §303(d) (IR 5) for impaired biota (cause unknown), metals (other than mercury), pathogens (E. coli, fecal), temperature. Check local advisories before you swim.
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Where this data comes from
19 measurements from 1 monitoring station, 2020. Retrieved from the EPA Water Quality Portal on 2026-08-21.
Collected and reported by
- Princeton Hydro LLC
PRINCETONHYDRO19 samples · 2020
Analytical methods
- 4500 P B ~ Phosphorus, sample preparation method
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