Mantua Reservoir is a productive, nutrient-rich eutrophic lake in Box Elder County, Utah. Water quality is graded F based on 2 sampling years through 2023. Compared to the 22 other monitored lakes in Box Elder County, Mantua Reservoir ranks #20 for water quality.
Source: EPA Water Quality Portal sampling records, Utah DNR, last sampled 2023-10-11. Grade methodology: LakeGrade methodology.
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Swimming Safety
Avoid swimming, very poor water quality, potential algae toxins
Water Quality Grade: F, Very Poor
Very murky, less than 3 ft of visibility. Chlorophyll-a: 39.7 µg/L. Trophic State Index: 64.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3 ft | F |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | 39.7 µg/L | F |
| Trophic State Index (TSI) | 64 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Mantua Reservoir
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Fishing Mantua Reservoir
Location
County Ranking
Ranked #20 of 23 lakes in Box Elder County
Cleaner Lakes Within 30 Miles
Mantua Reservoir holds Grade F. 2 nearby lakes hold higher grades.
- CMantua Reservoir NBox Elder County · 0.8 mi · Two grade letters higher (F → C)
- DMantua Reservoir SBox Elder County · 0.7 mi · Higher grade (F → D)
Nearby Lakes in Box Elder County
Explore Mantua Reservoir across LakeGrade
More Utah Lake Rankings
Other Grade F Lakes in Utah
Eutrophic Lakes in Utah
More records, surveys & data sources
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2023-10-11
Monitoring stations: 1