Thrapston Lake
Thrapston Lake in Lincs and Northants, England has official water-quality measurements, not a LakeQuality A–F grade. Phosphorus: 113 µg/L. Chlorophyll-a (algae): 13.5 µg/L.
Why Thrapston Lake has no A–F grade
Thrapston Lake in England is published with the authority's own measurements, not a LakeQuality letter. official authority class; not a LakeQuality A–F letter Sampling here has recorded phosphorus and algae (chlorophyll-a), but not water clarity.
A letter on the LakeQuality scale would be an invention, not an official class. Everything below that has been measured is still reported on this page.
Monitoring: the Environment Agency (England).
Thrapston Lake is a lake in Lincs and Northants County, England.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2026-07-17. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Thrapston Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
No clarity data. Phosphorus level: 113 µg/L. Chlorophyll-a: 13.5 µg/L. Trophic State Index: 64.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | 113 µg/L | Not graded |
| Chlorophyll-a (Algae) | 13.5 µg/L | Not graded |
| Trophic State Index (TSI) | 64 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Thrapston Lake
Compare lakeside cabins, hotels, and vacation rentals near Thrapston Lake in Lincs and Northants, England — 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.
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Fishing Thrapston Lake
Frequently asked questions about Thrapston Lake
What is the water quality of Thrapston Lake?
- Thrapston Lake in Lincs and Northants, England has official water-quality measurements, not a LakeQuality A–F grade. Phosphorus: 113 µg/L. Chlorophyll-a (algae): 13.5 µg/L.
Is Thrapston Lake safe to swim in?
- Thrapston Lake has official nutrient and clarity measurements, not a bacteria swim class and not a safety clearance. Algal blooms, currents, and depth are not covered. Always check local notices before swimming.
Explore Thrapston Lake across LakeGrade
More lakes in England
Where this data comes from
157 measurements from 1 monitoring station, 2016–2026. Retrieved from the Environment Agency (England; not the EPA Water Quality Portal) on 2026-08-16.
Collected and reported by
- Environment Agency (England)
ea-wqa157 samples · 2016–2026
Monitoring station identifiers (1)
AN-TMNRSFFD
Authority classifications are stored separately from LakeQuality A–F letters and are never blended. See methodology and data sources.
Data Sources
Water quality data from the EPA Water Quality Portal
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion
Most recent sample: 2026-07-17
Monitoring stations: 1