Sumner County Lake Quality
Kansas, 2 lakes, average grade F (Algae-prone)
Sumner 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 an A–F grade. The county-level summary describes that subset, not every water body listed. The county average is F — the most-stressed bracket in our rubric. Most monitored lakes here show persistent nutrient loading and algal pressure.
Most of the county's monitored lakes are shallow — under 50 feet — which means wind keeps the water column mixed all summer and sediment-bound phosphorus releases back into the surface layer whenever the bottom is disturbed. Wellington New City Lake (F) is the cleanest in the county.
Where to stay near Sumner County
Top-rated places to stay near Sumner County
Prices for Sep 11–13, 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 Sumner County?
Get lake water-quality report cards plus the best cabin & lodging deals near Sumner County — straight to your inbox. No spam, unsubscribe anytime.
Quick Answers for Sumner County
Planning a trip? Check special fishing regulations for Wellington New City Lake — or check the official Kansas fishing regulations.
All Lakes in Sumner County
2 lakes · 1 graded, 1 not rated1 graded lake · 1 not rated, hidden
| # | Lake | Grade | Clarity | Phosphorus | Algae | Trophic | Access |
|---|---|---|---|---|---|---|---|
| 1 | FWellington New City LakeSumner | F | 1.9 ft | 70.5 µg/L | 31 µg/L | No recent samples | Not recorded |
| NRSlate Creek Wildlife Area Wetland LakeSumner | NR | 0.7 ft | 315 µg/L | 30 µg/L | No recent samples | Not recorded |
NR = not rated: there is not enough recent sampling to support a letter. That is EPA Integrated Reporting Category 3 (insufficient information), not a failing grade. How grading works.
Lake Match
Which lake suits how you actually use one?
Six questions — swimming, fishing, quiet, cabins, drive time — and a shortlist of graded lakes that fit, with the water quality behind each one.
Other Counties in Kansas
See how Sumner County stacks up in the national county water-quality rankings, or browse the full directory of graded lakes across all United States (49 states), Canada (Ontario, Québec, Nova Scotia, British Columbia and Newfoundland and Labrador), and 38 other country hubs..
Source: EPA National Aquatic Resource Surveys, 2026.