Rock County, WI
Home Menu2025 Surface Water Sampling
| E. coli cfu per 100 ml | |
| 0-235 | Normal conditions |
| 235-999 | Caution advisory |
| 1000+ | High risk advisory* |
| Harmful Algal Blooms (Blue Green Algae) Observed* | |
*Surface waterways may not be suitable for recreational activities resulting in the ingestion of water.
Note: Licensed Beaches (B) are CLOSED when E. coli counts are 1000+
Weekly Test Sites
| Date Tested | Lakeview Campground - Lake Koshkonong (B) | Lakeland Campground - Lake Koshkonong (B) | Blackhawk Campground - Clear Lake (B) | Traxler Park Rock River | Preservation Park - Rock River |
| 05/19/2025 | 187 | 15 | 1 | 19 | 24 |
| 05/28/2025 | 4 | 299 | 1 | 15 | 28 |
| 06/02/2025 | 20 | 40 | 1 | 23 | 36 |
| 06/09/2025 | 67 | 75 | 5 | 23 | 68 |
| 06/16/2025 | 2,420 | 27 | 1 | 36 | 84 |
| 06/17/2025 | 1,733 | N/A | N/A | N/A | N/A |
| 06/19/2025 | 28 | N/A | N/A | N/A | N/A |
| 06/24/2025 | 1,733 | 461 | 6 | 141 | 411 |
| 06/26/2025 | 1046.2 | 648.8 | N/A | N/A | N/A |
| 06/30/2025 | 248 | 435 | 8 | 119 | 420 |
| 07/07/2025 | 32 | 73 | 1 | 64 | 93 |
| 07/14/2025 | 40 | 142 | 1 | 60 | 79 |
| 07/21/2025 | 9 | 21 | 3 | 59 | 66 |
| 07/28/2025 | 150 | >2,419 | 1 | 145 | >2,419 |
| 07/29/2025 | N/A | 920 | N/A | N/A | 73 |
| 08/04/2025 | 34 | 35 | 10 | 104 | 55 |
| 08/11/2025 | 122 | 411 | 57 | 228 | 1,414 |
| 08/18/2025 | 73 | 93 | 3 | 435 | 435 |
| 08/25/2025 | 31 | 93 | 1 | 30 | 50 |
| 09/02/2025 | 3 | 7 | <1 | 22 | 36 |
| 09/08/2025 | 33 | 6 | 2 | 31 | 22 |
| 09/15/2025 | 22 | 14 | 1 | 68 | 199 |
| 09/22/2025 |
28 |
12 | 2 | 53 | 236 |
09/29/2025 11 4 <1 21 42
Monthly Test Sites
| Date Tested | Gibbs Lake | Sugar River | Storrs Lake |
Palmer Park - Spring Brook |
Carver - Roehl Spring Brook | Yahara River - Murwin Park | Badfish Creek | Turtle Creek |
| 05/27/2025 | 387 | 50 | 31 | 272 | 579 | 55 | 276 | 122 |
| 06/24/2025 | 113 | 1,553 | 16 | >2419 | 756 | 488 | >2,419 | 194 |
| 07/02/2025 | N/A | 238 | N/A | N/A | N/A | N/A | 197 | N/A |
| 07/16/2025 | 13 | 411 | 5 | 1203 | 1,733 | 135 | 687 | 172 |
| 08/19/2025 | 72 | >2,419.6 | 48 | >2,419.6 | >2,419.6 | 6,570 | 6,778 | >2,419.6 |
| 08/26/2025 | N/A | 110 | N/A | N/A | N/A | N/A | N/A | 121 |
| 08/27/2025 | N/A | N/A | N/A | N/A | N/A | 130 | 317 | N/A |
| 09/17/2025 | 37 | 99 | 4 | 921 | 435 | 188 | 210 | 37 |
Seasonal Sites
| Date Tested | Kiwanis Pond | Otter Creek | Lake Leota | Saunders Creek | Traxler Park Lagoon | Leeson Park |
| 06/24/2025 | 55 | 629 | 50 | >2,419 | 131 | >2,419 |
| Date Tested | Stebbinsville - Yahara River | Marsh Creek | Bass Creek | Fisher Creek | Beckman Mill Pond | Beloit Lagoon |
| 06/24/2025 | 435 | >2,419 | 649 | >2,419 | 201 | 249 |
| 07/02/2025 | N/A | >2,419 | N/A | N/A | N/A | N/A |
