Updated Aug 2026
Maryland Lake Water Quality
94 lakes across 22 counties, 24 with a recent water-quality reading.
Lake Map
Get Maryland water-quality updates
New water-quality readings for Maryland lakes as MDE publishes them. Unsubscribe anytime.
Where to stay near Maryland's major lakes
Cabins, resorts, and vacation rentals around Deep Creek Lake and the other major Maryland lakes pinned on the map. Live availability and prices.
Top-rated places to stay near Deep Creek Lake
Prices for Oct 2–4, 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.
Maryland fishing & travel
Reservoirs in Maryland
View all 21 reservoirs →21 of 94 Maryland lakes (22%) are man-made reservoirs in the USACE National Inventory of Dams. 16 carry a High or Significant hazard rating. The oldest matched dam dates to 1921.
EPA-Impaired Lakes in Maryland
View all 24 impaired lakes →24 of 94 Maryland lakes (26%) are officially listed as impaired under Clean Water Act §303(d) in the most recent EPA ATTAINS reporting cycle. 19 have an approved Total Maximum Daily Load (TMDL) restoration plan.
Maryland Fishing & Recreation
Licenses, regulations, records, and where to fish across Maryland.
Counties
All 22 Maryland 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.
Maryland lists 94 lakes across 22 counties, 24 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.
Deep Creek Lake is the largest lake in this index at about 4,500 acres, one of 7 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.