Harrison County Lake Quality
Wisconsin, 3 lakes, average grade D (Poor)
Only 3 lakes in Harrison County carry an active grade. The county-level summary is therefore representative of those specific lakes, not necessarily of every water body in the county. The county-wide average grade is D — water quality issues are persistent across most of the monitored basins. 1 lakes fall into the F bracket outright.
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 North Bethany City Reservoir (B); the most-stressed is Harrison County Lake (F).
Quick Answers for Harrison County
Planning a trip? Check special fishing regulations for North Bethany City Reservoir, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
All Lakes in Harrison County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | North Bethany City Reservoir | B | 10.5 ft | - | 11 µg/L |
| 2 | Harrison County Lake Intake | D | 1.7 ft | - | 66.7 µg/L |
| 3 | Harrison County Lake | F | 1.5 ft | - | 70 µg/L |
Source: EPA National Aquatic Resource Surveys, 2026.