Gem County Lake Quality
Idaho, 2 lakes, measured by Idaho DEQ
Gem County holds 2 monitored lakes. With a sample that small the county-level summary describes those specific waters, not necessarily every water body in the county. 1 of those lake carry recent nutrient and algae readings. The county-level summary describes that subset, not every water body listed. Taken together, the monitored lakes of Gem County sit near the low-nutrient end of the Idaho range.
The county's lakes lean shallow, which makes the readings sensitive to wind, sediment-resuspension, and any nutrient inputs from the watershed. The cleanest measured lake is Black Cnyn Reservoir Ns of.
Where to stay near Gem County
Top-rated places to stay near Gem County
Prices for Oct 30–Nov 1, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a trip to Gem County?
Get lake water-quality updates plus the best cabin & lodging deals near Gem County — straight to your inbox. No spam, unsubscribe anytime.
Quick Answers for Gem County
Planning a trip? Check special fishing regulations for Black Cnyn Reservoir Ns of — or check the official Idaho fishing regulations.
All Lakes in Gem County
2 lakes · 1 ranked on readings, 1 without enough sampling1 lake ranked on readings · 1 without enough sampling, hidden
| # | Lake | Clarity | Phosphorus | Algae | Trophic | Access |
|---|---|---|---|---|---|---|
| 1 | Black Cnyn Reservoir Ns ofGem | 7.5 ft | 29.5 µg/L | 3.1 µg/L | No recent samples | ✓ Public |
| Black Canyon ReservoirGem | No recent samples | No recent samples | No recent samples | No recent samples | Not recorded |
NR = no nutrient or algae reading on record. The measurements are published as the authority reports them. Where the data comes from.
Lake Match
Which lake suits how you actually use one?
Six questions — swimming, fishing, quiet, cabins, drive time — and a shortlist of lakes that fit, with the water quality behind each one.
Other Counties in Idaho
Browse every Idaho lake, or the full directory of lakes across all United States (49 states), Canada (Ontario, Québec, Nova Scotia, British Columbia and Newfoundland and Labrador), and 38 other country hubs..
Source: the Idaho Department of Environmental Quality. See data sources.