Williamson County Lake Quality
Texas, 1 lakes, average grade B (Good)
Only 1 lakes in Williamson 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 lands at B — solid water quality with most lakes carrying clear summer transparency and low-to-moderate phosphorus.
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 Georgetown (B) is the cleanest in the county.
Quick Answers for Williamson County
Planning a trip? Check special fishing regulations for Lake Georgetown — or check the official Texas fishing regulations.
All Lakes in Williamson County
| Rank | Lake | Grade | Clarity | Phosphorus |
|---|---|---|---|---|
| 1 | Lake Georgetown | B | 5.6 ft | 20 µg/L |
Other Counties in Texas
See how Williamson 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 Williamson County
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Source: EPA National Aquatic Resource Surveys, 2026.