Marion-Lou Lake
Marion County, FloridaView mapDirections
Florida DEP publishes the water-quality measurements for Marion-Lou Lake. Here is what has been measured.
- Eutrophic
- Impaired · pH / acidity
- 26 ft max depth
- Public access
Marion-Lou Lake in Marion County, Florida has water-quality measurements published by Florida DEP, shown here as reported. Water clarity: 3.3 ft visibility. Phosphorus: 18.5 µg/L.
Marion-Lou Lake is a productive, nutrient-rich eutrophic lake in Marion County, Florida with an estimated average depth of about 26 feet. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 17 other monitored lakes in Marion County, Marion-Lou Lake ranks #14 for water quality.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2025-03-27. Methodology: how these readings are compared.
What Marion-Lou Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
Swimming conditions
Readings onlyLow algae
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Marion-Lou Lake is listed impaired under Clean Water Act §303(d) (IR 4C) for pH / acidity. Check local advisories before you swim.
Whether Marion-Lou Lake is safe to swim in today is a call for the Florida Department of Environmental Protection and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Marion-Lou Lake
These are the measurements Florida DEP publishes for Marion-Lou Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 3.3 ft of visibility. Phosphorus 18.5 µg/L. TSI 53.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3.3ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 18.5µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 53 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Marion-Lou Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
~26 ft est.
Public access
Yes
Listed by Florida DEP
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Florida has not published bathymetry for Marion-Lou Lake.
Lake Size & Watershed
Watershed (drainage) area
67 sq mi
HydroLAKES / HydroSHEDS
Surface area
94 acres
HydroLAKES / HydroSHEDS
Shoreline
1.4 mi
HydroLAKES / HydroSHEDS
Elevation
46 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Recreation & Access
- Lake Lou Unimproved Access - Ocala National ForestPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Marion-Lou Lake
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Top-rated places to stay near Marion-Lou Lake
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Fishing Marion-Lou Lake
Water quality readings over time
3 seasons of samples on record (2022–2024). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Improving3 years
Phosphorus
Improving-2.25 µg/L/yr3 years
EPA Impairment Status
Marion-Lou Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 4C).
Causes of impairment
Designated uses not supporting: Aquatic life.
Source: EPA ATTAINS assessment unit FL2775D · Official waterbody report
Nearby Lakes in Marion County
Frequently asked questions about Marion-Lou Lake
Where is Marion-Lou Lake?
- Marion-Lou Lake is a lake in Marion County, Florida. Its water-quality measurements are published by Florida DEP and shown on this page as reported.
What is the water quality of Marion-Lou Lake?
- Marion-Lou Lake in Marion County, Florida has water-quality measurements published by Florida DEP, shown here as reported. Water clarity: 3.3 ft visibility. Phosphorus: 18.5 µg/L.
Is Marion-Lou Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Marion-Lou Lake is listed impaired under Clean Water Act §303(d) (IR 4C) for pH / acidity. Check local advisories before you swim.
How deep is Marion-Lou Lake?
- No published bathymetric survey covers Marion-Lou Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 26 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Are there boat ramps on Marion-Lou Lake?
- Marion-Lou Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lake Lou Unimproved Access - Ocala National Forest. Public access is listed as yes.
Can I fish at Marion-Lou Lake?
- Marion-Lou Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Florida's fish and wildlife agency, so check its current regulations before you go.
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Where this data comes from
128 measurements from 3 monitoring stations, 2022–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- FLORIDA LAKEWATCH
21FLKWAT_WQX128 samples · 2022–2025
Monitoring station identifiers (3)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Named boat-access points from the USGS National Boat Ramps inventory