Lake Mariam
Polk County, FloridaView mapDirections
Florida DEP publishes the water-quality measurements for Lake Mariam. Here is what has been measured.
- Eutrophic
- Public access
- Limited data
Lake Mariam in Polk County, Florida has water-quality measurements published by Florida DEP, shown here as reported. Water clarity: 1.6 ft visibility. Phosphorus: 52 µg/L.
Lake Mariam is a productive, nutrient-rich eutrophic lake in Polk County, Florida. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 176 other monitored lakes in Polk County, Lake Mariam ranks #105 for water quality.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2022-09-19. Methodology: how these readings are compared.
What Lake Mariam is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
Swimming conditions
Readings onlyLimited data
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. Check local advisories before you swim.
Whether Lake Mariam 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 Lake Mariam
These are the measurements Florida DEP publishes for Lake Mariam, 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 1.6 ft of visibility. Phosphorus 52 µg/L. TSI 66.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 1.6ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 52µg/L | Fair 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. | 66 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Lake Mariam
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Lake Mariam typically sits around 92°F at the surface in September. Summer average is about 87°F. Usually warmest in Sep (about 92°F) and coldest in Dec (about 49°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (49°F) to its warmest (92°F).
Typical surface water temperature by month, from 8 field readings (2010–2022) via the EPA Water Quality Portal. See the full Lake Mariam water temperature breakdown →
Recreation & Access
- Lake Mariam Public Boat RampPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Lake Mariam
Compare lakeside cabins, hotels, and vacation rentals near Lake Mariam in Polk County, Florida — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
Top-rated places to stay near Lake Mariam
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Fishing Lake Mariam
Water Quality Trend: Worsening
Based on 6 years of monitoring (2020–2025).
Water clarity
Worsening6 years
Phosphorus
Stable-0.27 µg/L/yr6 years
Nearby Lakes in Polk County
Frequently asked questions about Lake Mariam
Where is Lake Mariam?
- Lake Mariam is a lake in Polk County, Florida. Its water-quality measurements are published by Florida DEP and shown on this page as reported.
What is the water quality of Lake Mariam?
- Lake Mariam in Polk County, Florida has water-quality measurements published by Florida DEP, shown here as reported. Water clarity: 1.6 ft visibility. Phosphorus: 52 µg/L.
Is Lake Mariam safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Lake Mariam?
- Lake Mariam typically sits around 92°F at the surface in September, from 8 EPA Water Quality Portal field readings (2010–2022). That is a typical value for the month, not a live reading.
Are there boat ramps on Lake Mariam?
- Lake Mariam has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lake Mariam Public Boat Ramp. Public access is listed as yes.
Can I fish at Lake Mariam?
- Lake Mariam 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.
Explore Lake Mariam across LakeQuality
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Where this data comes from
12 measurements from 3 monitoring stations, 2020–2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Submitting organization not recorded for these samples10 samples · 2022
- Submitting organization not recorded for these samples2 samples · 2020
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
Named boat-access points from the USGS National Boat Ramps inventory