Marion County Lake Quality
Texas, 4 lakes, average grade D (Poor)
Only 4 lakes in Marion 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. On average, Marion County lakes grade D, with phosphorus loading and reduced clarity showing up across most of the dataset.
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. Lake O the Pines Mid Lake (D) is the cleanest in the county.
Quick Answers for Marion County
Planning a trip? Check special fishing regulations for Lake O the Pines Mid Lake — or check the official Texas fishing regulations.
All Lakes in Marion County
| Rank | Lake | Grade | Clarity | Phosphorus |
|---|---|---|---|---|
| 1 | Lake O the Pines Mid Lake | D | 2.7 ft | 30 µg/L |
| 2 | Lake O the Pines | D | 2.5 ft | 40 µg/L |
| 3 | Lake Opines | D | 2 ft | 50 µg/L |
| 4 | Lake O the Pines | D | 2 ft | 70 µg/L |
Other Counties in Texas
See how Marion County stacks up in the national county water-quality rankings, or browse the full directory of graded lakes across all 17 states.
Where to stay near Marion County
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Source: EPA National Aquatic Resource Surveys, 2026.