Round Lake
McHenry County, North DakotaView mapDirections
ND DEQ publishes the water-quality measurements for Round Lake. Here is what has been measured.
- 38 ft max depth
- Limited data
Round Lake in McHenry County, North Dakota has water-quality measurements published by ND DEQ, shown here as reported. Water clarity: 12.1 ft visibility. Chlorophyll-a (algae): 2.4 µg/L.
Round Lake is a lake in McHenry County, North Dakota with an estimated average depth of about 38 feet.
Source: EPA Water Quality Portal sampling records, NDDEQ, last sampled 2021-10-12. Methodology: how these readings are compared.
What Round Lake is good for
From access and monitoring records, not editorial picks.
- Clear water12.1 ft of visibility
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Round Lake is safe to swim in today is a call for the North Dakota Department of Environmental Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Round Lake
These are the measurements ND DEQ publishes for Round 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 12.1 ft. Chlorophyll-a 2.4 µg/L. TSI 40.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 12.1ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| Chlorophyll-a (algae) | 2.4µg/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. | 40 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Round Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Round Lake typically sits around 50°F at the surface in October. Summer average is about 60°F. Usually warmest in Aug (about 64°F) and coldest in May (about 47°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (47°F) to its warmest (64°F).
Typical surface water temperature by month, from 13 field readings (2010–2021) via the EPA Water Quality Portal. See the full Round Lake water temperature breakdown →
Lake Details
Max depth
~38 ft est.
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. North Dakota has not published bathymetry for Round Lake.
Lake Size & Watershed
Watershed (drainage) area
51 sq mi
HydroLAKES / HydroSHEDS
Surface area
714 acres
HydroLAKES / HydroSHEDS
Shoreline
4.4 mi
HydroLAKES / HydroSHEDS
Elevation
1,529 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Stays via Stay22
Stays near Round Lake
Compare lakeside cabins, hotels, and vacation rentals near Round Lake in McHenry County, North Dakota — 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.
Top-rated places to stay near Round Lake
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Fishing Round Lake
Nearby Lakes in McHenry County
Frequently asked questions about Round Lake
Where is Round Lake?
- Round Lake is a lake in McHenry County, North Dakota. Its water-quality measurements are published by ND DEQ and shown on this page as reported.
What is the water quality of Round Lake?
- Round Lake in McHenry County, North Dakota has water-quality measurements published by ND DEQ, shown here as reported. Water clarity: 12.1 ft visibility. Chlorophyll-a (algae): 2.4 µg/L.
Is Round Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Round Lake?
- Round Lake typically sits around 50°F at the surface in October, from 13 EPA Water Quality Portal field readings (2010–2021). That is a typical value for the month, not a live reading.
How deep is Round Lake?
- No published bathymetric survey covers Round Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 38 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
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Where this data comes from
8 measurements from 1 monitoring station, 2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- North Dakota Department Of Environmental Quality
21NDHDWQ_WQX8 samples · 2021
Analytical methods
- 447.0 ~ EPA; Chlorophyll a and b in phytoplankton by HPLC/UV
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Depth, fish, and access data from North Dakota Game & Fish