Arrowrock Reservoir is a mesotrophic lake in Elmore County, Idaho. Water quality is graded B based on 3 sampling years through 2015. Compared to the 7 other monitored lakes in Elmore County, Arrowrock Reservoir ranks #5 for water quality.
Source: EPA Water Quality Portal sampling records, Idaho DNR, last sampled 2015-02-11. Grade methodology: LakeGrade methodology.
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Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
Good clarity, visible to about 12.5 ft. Phosphorus level: 35 µg/L. Chlorophyll-a: 1.5 µg/L. Trophic State Index: 44.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 12.5 ft | B |
| Phosphorus | 35 µg/L | C |
| Chlorophyll-a (Algae) | 1.5 µg/L | A |
| Trophic State Index (TSI) | 44 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Arrowrock Reservoir
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Fishing Arrowrock Reservoir
Location
County Ranking
Ranked #5 of 8 lakes in Elmore County
Cleaner Lakes Within 30 Miles
Arrowrock Reservoir holds Grade B. One nearby lake has a higher grade.
See full comparison →Nearby Lakes in Elmore County
Explore Arrowrock Reservoir across LakeGrade
More Idaho Lake Rankings
Other Grade B Lakes in Idaho
Owyhee County · Clarity: 10.8 ft
Gem County · Clarity: 7.5 ft
Canyon County · Clarity: 7.2 ft
Canyon County · Clarity: 7.2 ft
Boise County · Clarity: 23.3 ft
Valley County · Clarity: 8.5 ft
Mesotrophic Lakes in Idaho
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: 2015-02-11
Monitoring stations: 1