Lakes With Algae Problems in Oregon
16 lakes in Oregon report elevated algae levels (chlorophyll-a above 20 µg/L). These lakes are most likely to develop blue-green algae blooms during warm, calm summer weather. Avoid swimming during visible blooms and rinse pets after contact.
Ranked List
| # | Lake | County | Grade | Clarity | Phosphorus | Algae |
|---|---|---|---|---|---|---|
| 1 | Shoalwater Bay Lake | Klamath | F | - | 215 µg/L | 143.5 µg/L |
| 2 | Cold Springs Reservoir | Umatilla | F | - | - | 126 µg/L |
| 3 | Rattlesnake Point Lake | Klamath | F | - | 185 µg/L | 124.5 µg/L |
| 4 | Brownlee Reservoir | Baker | F | - | - | 108 µg/L |
| 5 | Mid-North Lake | Klamath | F | - | 180 µg/L | 81.1 µg/L |
| 6 | Mid-Trench Lake | Klamath | F | - | 240 µg/L | 80.6 µg/L |
| 7 | Williamson River Outlet Lake | Klamath | F | - | 165 µg/L | 67.9 µg/L |
| 8 | Agency Lake South | Klamath | F | - | 110 µg/L | 61.6 µg/L |
| 9 | Thief Valley Reservoir | Union | F | - | - | 51.2 µg/L |
| 10 | Mckay Lake | Umatilla | NR | 3.3 ft | 121.5 µg/L | 49.4 µg/L |
| 11 | Malheur Lake | Harney | F | - | 460.5 µg/L | 45.5 µg/L |
| 12 | Diamond Lake | Douglas | F | - | - | 43.4 µg/L |
| 13 | Cullaby Lake | Clatsop | F | - | - | 36.8 µg/L |
| 14 | Tenmile Lake | Coos | F | - | - | 30.6 µg/L |
| 15 | Lake Billy Chinook Deschutes R Arm @ Floating Station | Jefferson | D | - | 35 µg/L | 27.7 µg/L |
| 16 | Crooked River Arm Lake | Jefferson | D | - | 60 µg/L | 24.6 µg/L |
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