Semer Water
Semer Water in Yorkshire, England has official water-quality measurements, not a LakeQuality A–F grade. Phosphorus: 36 µg/L. Chlorophyll-a (algae): 3.8 µg/L.
Why Semer Water has no A–F grade
Semer Water 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).
Semer Water is a lake in Yorkshire County, England.
Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2026-06-17. Grade methodology: LakeGrade methodology.
Watch Semer Water water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Semer Water
These readings exist but do not meet the evidence bar for an A–F grade — see why.
No clarity data. Phosphorus level: 36 µg/L. Chlorophyll-a: 3.8 µg/L. Trophic State Index: 50.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | 36 µg/L | Not graded |
| Chlorophyll-a (Algae) | 3.8 µg/L | Not graded |
| Trophic State Index (TSI) | 50 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Semer Water
Compare lakeside cabins, hotels, and vacation rentals near Semer Water in Yorkshire, 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.
Top-rated places to stay near Semer Water
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Fishing Semer Water
Frequently asked questions about Semer Water
What is the water quality of Semer Water?
- Semer Water in Yorkshire, England has official water-quality measurements, not a LakeQuality A–F grade. Phosphorus: 36 µg/L. Chlorophyll-a (algae): 3.8 µg/L.
Is Semer Water safe to swim in?
- Semer Water 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 Semer Water across LakeGrade
More lakes in England
Where this data comes from
145 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-wqa145 samples · 2016–2026
Monitoring station identifiers (1)
NE-40000443
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: 2026-06-17
Monitoring stations: 1