Grundy County Lake Quality
Missouri, 5 lakes — no lake here has enough monitoring data for a grade
Grundy County has 5 monitored lakes — a thin enough sample that one or two stressed lakes can move the county average noticeably. Use the per-lake pages below for what actually matters. No lake in Grundy County has enough sampling behind it for an A–F grade yet. The 5 monitored lakes below carry whatever clarity, phosphorus, and chlorophyll-a measurements exist.
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.
Where to stay near Grundy County
Top-rated places to stay near Grundy 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 Grundy County?
Get lake water-quality report cards plus the best cabin & lodging deals near Grundy County — straight to your inbox. No spam, unsubscribe anytime.
Quick Answers for Grundy County
Planning a trip? Check special fishing regulations for Crowder S.P. Lake — or check the official Missouri fishing regulations.
All Lakes in Grundy County
5 lakes · 0 graded, 5 not rated0 graded lakes · 5 not rated, hidden
| # | Lake | Grade | Clarity | Phosphorus | Algae | Trophic | Access |
|---|---|---|---|---|---|---|---|
| NRCrowder S.P. LakeGrundy | NR | 1 ft | 110 µg/L | 176.4 µg/L | No recent samples | Not recorded | |
| NRLeisure LakeGrundy | NR | No recent samples | No recent samples | No recent samples | No recent samples | Not recorded | |
| NRTrenton City ReservoirGrundy | NR | No recent samples | No recent samples | No recent samples | No recent samples | Not recorded | |
| NRTrenton Lower LakeGrundy | NR | No recent samples | No recent samples | No recent samples | No recent samples | Not recorded | |
| NRTrenton Upper LakeGrundy | NR | No recent samples | No recent samples | No recent samples | 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 Missouri
See how Grundy 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.