Dallas County Lake Quality

Dallas County has 2 monitored lakes — a thin enough sample that one or two stressed lakes can move the county average noticeably. Use the per-lake pages below for what actually matters. Every one of those lakes carries an A–F grade, so the county-level summary covers the full set rather than a monitored subset. Dallas County averages to a C. The distribution behind that average matters more than the letter: a few stressed lakes versus many decent ones can produce the same average as the inverse.

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 Dale Maffitt Reservoir (A); the most-stressed is Beaver Lake (F).