Updated Aug 2026
Alaska Lake Water Quality
2,244 lakes across 33 counties, 2 with a recent water-quality reading.
Lake Map
Get Alaska water-quality updates
New water-quality readings for Alaska lakes as Alaska DEC publishes them. Unsubscribe anytime.
Where to stay near Alaska's major lakes
Cabins, resorts, and vacation rentals around Iliamna Lake and the other major Alaska lakes pinned on the map. Live availability and prices.
Top-rated places to stay near Iliamna Lake
Prices for Oct 9–11, 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.
Alaska fishing & travel
EPA-Impaired Lakes in Alaska
View all 3 impaired lakes →3 of 2,244 Alaska lakes (0%) are officially listed as impaired under Clean Water Act §303(d) in the most recent EPA ATTAINS reporting cycle. 3 have an approved Total Maximum Daily Load (TMDL) restoration plan.
Alaska Fishing & Recreation
Licenses, regulations, records, and where to fish across Alaska.
Counties
All 33 Alaska counties, ranked by average lake water quality. Compare them against every county nationwide in the county rankings, browse the full directory of lakes, or pick a different state.
Alaska lists 2,244 lakes across 33 counties, 2 of them with a recent clarity, phosphorus or algae reading. The rest are here because they are real named lakes, listed for their size, depth and location.
Iliamna Lake is the largest lake in this index at about 654,517 acres, one of 524 here that clear 500 acres. The rest run smaller, and small and shallow is where nutrient loading shows up first, because there is less water to dilute it and the bottom sediment stays within reach of the sun.
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.
Source: EPA National Aquatic Resource Surveys and the EPA Water Quality Portal.
More on lake water quality
A data snapshot of the lakes we track: the clearest and the greenest states, and where the water is improving.
How nutrient and algae readings are read against EPA ecoregion condition classes, what each class means in the water, and why a clean reading is not a clearance.
The clearest lakes in America, ranked by measured Secchi depth in feet from EPA monitoring data — and why the famously clear lakes are missing.