Sumter-Big Gant Lake
Sumter County, Florida93 acresView mapDirections
Florida DEP publishes the water-quality measurements for Sumter-Big Gant Lake. Here is what has been measured.
- Eutrophic
- 52 ft max depth
- Public access
Sumter-Big Gant Lake in Sumter County, Florida has water-quality measurements published by Florida DEP, shown here as reported. Water clarity: 3 ft visibility. Phosphorus: 56.5 µg/L. Surface area: 93 acres.
Sumter-Big Gant Lake is a 93-acre productive, nutrient-rich eutrophic lake in Sumter County, Florida with an estimated average depth of about 52 feet. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available. Compared to the 10 other monitored lakes in Sumter County, Sumter-Big Gant Lake ranks #9 for water quality.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2025-04-22. Methodology: how these readings are compared.
Sumter-Big Gant Lake covers about 93 acres in Sumter County. For a place on the water, look through cabin and lake-house rentals near Sumter-Big Gant Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
Swimming conditions
Readings onlyModerate 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. Check local advisories before you swim.
Whether Sumter-Big Gant 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 Sumter-Big Gant Lake
These are the measurements Florida DEP publishes for Sumter-Big Gant 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 ft of visibility. Phosphorus 56.5 µg/L. TSI 62.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 56.5µg/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. | 62 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Sumter-Big Gant Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Sumter-Big Gant Lake typically sits around 68°F at the surface in December. Usually warmest in May (about 78°F) and coldest in Jan (about 60°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (60°F) to its warmest (78°F).
Typical surface water temperature by month, from 12 field readings (2010–2014) via the EPA Water Quality Portal. See the full Sumter-Big Gant Lake water temperature breakdown →
Lake Details
Max depth
~52 ft est.
Surface area
93 acres
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 Sumter-Big Gant Lake.
Lake Size & Watershed
Watershed (drainage) area
5 sq mi
HydroLAKES / HydroSHEDS
Shoreline
1 mi
HydroLAKES / HydroSHEDS
Elevation
69 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.
Stays via Stay22
Stays near Sumter-Big Gant Lake
Compare lakeside cabins, hotels, and vacation rentals near Sumter-Big Gant Lake in Sumter 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 Sumter-Big Gant Lake
Prices for Oct 16–18, 4 adults. Change dates on the map below.
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Fishing Sumter-Big Gant Lake
Water Quality Trend: Worsening
Based on 5 years of monitoring (2020–2024).
Water clarity
Worsening5 years
Phosphorus
Worsening+4.5 µg/L/yr5 years
Reservoir Info (USACE NID)
Sumter-Big Gant Lake is a man-made reservoir impounded by the S-11 (completed 1965), built primarily for water supply on the Canal C; other-type dam, 20 ft tall and 64 ft long.
- Surface area
- 93 ac
- Normal storage
- 1,181 ac-ft
- Max storage
- 1,250 ac-ft
- Drainage area
- 20 sq mi
- Hazard class
- Significant
- Owner
- SWFWMD
All listed purposes: Water Supply;Flood Risk Reduction.
Source: USACE National Inventory of Dams, NID ID FL77000 · Operator website · Matched by proximity (0.73 km)
Nearby Lakes in Sumter County
Frequently asked questions about Sumter-Big Gant Lake
Where is Sumter-Big Gant Lake?
- Sumter-Big Gant Lake is a lake in Sumter County, Florida. Its water-quality measurements are published by Florida DEP and shown on this page as reported.
What is the water quality of Sumter-Big Gant Lake?
- Sumter-Big Gant Lake in Sumter County, Florida has water-quality measurements published by Florida DEP, shown here as reported. Water clarity: 3 ft visibility. Phosphorus: 56.5 µg/L. Surface area: 93 acres.
Is Sumter-Big Gant Lake 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 Sumter-Big Gant Lake?
- Sumter-Big Gant Lake typically sits around 68°F at the surface in December, from 12 EPA Water Quality Portal field readings (2010–2014). That is a typical value for the month, not a live reading.
How deep is Sumter-Big Gant Lake?
- No published bathymetric survey covers Sumter-Big Gant Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 52 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 93 acres.
Can I fish at Sumter-Big Gant Lake?
- Public access to Sumter-Big Gant Lake is listed as yes on the lake record. 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
131 measurements from 3 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- FLORIDA LAKEWATCH
21FLKWAT_WQX131 samples · 2020–2025
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
Lake size & watershed from HydroLAKES (HydroSHEDS)