Union Parish County Lake Quality

Union Parish County has 1 monitored lake — 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 lake carries recent nutrient and algae readings, so the county-level summary covers the full set rather than a monitored subset. Most monitored lakes in Union Parish County are productive, shallow basins; each lake page shows its own phosphorus and chlorophyll-a readings beside the EPA condition class.

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 D'Arbonne has the lowest nutrient and algae readings in the county.