Ogontz Lake
Grafton County, New Hampshire74 acresView mapDirections
No nutrient or algae sampling on record from NHDES for this lake.
- Impaired · Mercury
- 70 ft max depth
Ogontz Lake in Grafton County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Maximum depth: 70 ft. Surface area: 74 acres.
Ogontz Lake is a 74-acre lake in Grafton County, New Hampshire with a maximum depth of 70 feet (21-foot average).
Source: EPA Water Quality Portal sampling records, your state environmental agency. Methodology: how these readings are compared.
What Ogontz Lake is good for
From access and monitoring records, not editorial picks.
- Deep water70 ft surveyed max depth
Swimming conditions
No readingNot rated
Nutrient and algae readings are not a swimming clearance. Ogontz Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether Ogontz Lake is safe to swim in today is a call for the New Hampshire Department of Environmental Services and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Ogontz Lake
These are the measurements NHDES publishes for Ogontz Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data. TSI undefined.
Ask about Ogontz Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
70 ft
Average depth
21 ft
Surface area
74 acres
Shoreline
1.9 mi
The depth above comes from a bathymetric survey of this lake, not from a regional estimate.
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Fishing Ogontz Lake
EPA Impairment Status
Ogontz Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Fish consumption.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit NHLAK801030502-02 · Official waterbody report
Nearby Lakes in Grafton County
Frequently asked questions about Ogontz Lake
Where is Ogontz Lake?
- Ogontz Lake is a lake in Grafton County, New Hampshire. Its water-quality measurements are published by NHDES and shown on this page as reported.
What is the water quality of Ogontz Lake?
- Ogontz Lake in Grafton County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Maximum depth: 70 ft. Surface area: 74 acres.
Is Ogontz Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Ogontz Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
How deep is Ogontz Lake?
- Ogontz Lake has a maximum depth of 70 feet and an average depth of 21 feet. The lake covers 74 acres.
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Where this data comes from
Measurements for Ogontz Lake come from the EPA Water Quality Portal. Per-sample source details are not recorded for this lake.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database