Lake Winnepocket-Pratt Cove
Merrimack County, New Hampshire1 acresView mapDirections
NHDES publishes the water-quality measurements for Lake Winnepocket-Pratt Cove. Here is what has been measured.
- Oligotrophic
- Limited data
Lake Winnepocket-Pratt Cove in Merrimack County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Phosphorus: 5.6 µg/L. Surface area: 1 acres.
Lake Winnepocket-Pratt Cove is a 1-acre cold, clear oligotrophic lake in Merrimack County, New Hampshire. Compared to the 40 other monitored lakes in Merrimack County, Lake Winnepocket-Pratt Cove ranks #18 for water quality.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2024-06-12. Methodology: how these readings are compared.
Swimming conditions
Readings onlyLimited data
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. Check local advisories before you swim.
Whether Lake Winnepocket-Pratt Cove 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 Lake Winnepocket-Pratt Cove
These are the measurements NHDES publishes for Lake Winnepocket-Pratt Cove, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data. Phosphorus 5.6 µg/L. TSI 29.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | No reading How deep a black-and-white disk stays visible from the surface. Higher is clearer. | |
| Total phosphorus | 5.6µg/L | Good 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. | 29 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Lake Winnepocket-Pratt Cove
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
1 acres
No bathymetric survey has been published for Lake Winnepocket-Pratt Cove, so its depth is not documented here.
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Fishing Lake Winnepocket-Pratt Cove
Reservoir Info (USACE NID)
Lake Winnepocket-Pratt Cove is a man-made reservoir impounded by the Blackwater Dam - Dodge Estate Dike (completed 1941), built primarily for flood risk reduction on the Blackwater River; gravity-type dam, 18 ft tall and 400 ft long.
- Surface area
- 1 ac
- Normal storage
- 0 ac-ft
- Max storage
- 93,400 ac-ft
- Drainage area
- 128 sq mi
- Hazard class
- High
- Owner
- USACE - New England District
Source: USACE National Inventory of Dams, NID ID NH03847 · Operator website · Matched by proximity (0.44 km)
Nearby Lakes in Merrimack County
Frequently asked questions about Lake Winnepocket-Pratt Cove
Where is Lake Winnepocket-Pratt Cove?
- Lake Winnepocket-Pratt Cove is a lake in Merrimack County, New Hampshire. Its water-quality measurements are published by NHDES and shown on this page as reported.
What is the water quality of Lake Winnepocket-Pratt Cove?
- Lake Winnepocket-Pratt Cove in Merrimack County, New Hampshire has water-quality measurements published by NHDES, shown here as reported. Phosphorus: 5.6 µg/L. Surface area: 1 acres.
Is Lake Winnepocket-Pratt Cove safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Explore Lake Winnepocket-Pratt Cove across LakeQuality
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Where this data comes from
5 measurements from 1 monitoring station, 2022–2024. Retrieved from the EPA Water Quality Portal on 2026-08-21.
Collected and reported by
- New Hampshire Department Of Environmental Services (BEACH)
111133005 samples · 2022–2024
Analytical methods
- 10-115-01-1 F ~ LACHAT; Total Phosphorus- Manual persulfate digest
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.