Johnson County Lake Quality
Missouri, 7 lakes, average grade B (Good)
Johnson County has 7 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. 3 of those lakes carry an A–F grade. The county-level summary describes that subset, not every water body listed. With an average grade of B, Johnson County sits comfortably above the Missouri median.
The county's lakes lean shallow, which makes the grades sensitive to wind, sediment-resuspension, and any nutrient inputs from the watershed. The cleanest lake on the books is Lake Buteo (A); the most-stressed is Hazel Hill Lake by Dam (D).
Where to stay near Johnson County
Top-rated places to stay near Johnson 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 Johnson County?
Get lake water-quality report cards plus the best cabin & lodging deals near Johnson County — straight to your inbox. No spam, unsubscribe anytime.
Quick Answers for Johnson County
Planning a trip? Check special fishing regulations for Lake Buteo — or check the official Missouri fishing regulations.
All Lakes in Johnson County
7 lakes · 3 graded, 4 not rated3 graded lakes · 4 not rated, hidden
| # | Lake | Grade | Clarity | Phosphorus | Algae | Trophic | Access |
|---|---|---|---|---|---|---|---|
| 1 | ALake ButeoJohnson | A | 5.6 ft | 20 µg/L | 4 µg/L | No recent samples | Not recorded |
| 2 | ARock Lake Village LakeJohnson | A | 4.3 ft | 16 µg/L | 4.8 µg/L | No recent samples | Not recorded |
| 3 | DHazel Hill Lake by DamJohnson | D | 2 ft | 59.3 µg/L | 28 µg/L | No recent samples | ✓ Public |
| NRHolden City LakeJohnson | NR | No recent samples | No recent samples | No recent samples | No recent samples | ✓ Public | |
| NRShirley LakeJohnson | NR | No recent samples | No recent samples | No recent samples | No recent samples | Not recorded | |
| NREcho LakeJohnson | NR | No recent samples | No recent samples | No recent samples | No recent samples | Not recorded | |
| NRRock Island LakeJohnson | 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 Johnson 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.