Lake Marseilles-Terre du Lac Lakes
St. Francois County, WisconsinOligotrophic
Lake Marseilles-Terre du Lac Lakes is a 56-acre cold, clear oligotrophic lake in St. Francois County, MO. Water quality is graded A based on 3 sampling years through 2020. Compared to the 3 other monitored lakes in St. Francois County, Lake Marseilles-Terre du Lac Lakes ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, local state DNR records, last sampled 2020-08-31. Grade methodology: LakeGrade methodology.
Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
Good clarity, visible to about 14.1 ft. Phosphorus level: 7.4 µg/L. Chlorophyll-a: 2.4 µg/L. Trophic State Index: 37.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 14.1 ft | B |
| Phosphorus | 7.4 µg/L | A |
| Chlorophyll-a (Algae) | 2.4 µg/L | A |
| Trophic State Index (TSI) | 37 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 56 acres |
Location
County Ranking
Ranked #2 of 4 lakes in St. Francois County
Nearby Lakes in St. Francois County
More Wisconsin Lake Rankings
Other Grade A Lakes in Wisconsin
Jefferson County · Clarity: 12.9 ft
Washington County · Clarity: 11.1 ft
Warren County · Clarity: 12.6 ft
Taney County · Clarity: 13.3 ft
Taney County · Clarity: 12.6 ft
Iron County · Clarity: 13.1 ft
Oligotrophic Lakes in Wisconsin
Reservoir Info (USACE NID)
Lake Marseilles-Terre du Lac Lakes is a man-made reservoir impounded by the Lac Marseilles Dam (completed 1971), built primarily for recreation on the TR-BIG RIVER; earth-type dam, 69 ft tall and 1,185 ft long.
- Surface area
- 56 ac
- Normal storage
- 1,900 ac-ft
- Max storage
- 1,900 ac-ft
- Drainage area
- 0.59 sq mi
- Hazard class
- High
- Owner
- TERRE DU LAC POA
Source: USACE National Inventory of Dams, NID ID MO30282 · Operator website · Matched by proximity (0.1 km)
EPA Impairment Status
Lake Marseilles-Terre du Lac Lakes is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MO_7614.00 · Official waterbody report · Matched by proximity (0.31 km)
Data Sources
Water quality data from the EPA Water Quality Portal
Impairment status from EPA ATTAINS 303(d) database
Grading methodology based on Metropolitan Council standards
Most recent sample: 2020-08-31
Monitoring stations: 1