Dias Lake
Volusia County, FloridaView mapDirections
Florida DEP publishes the water-quality measurements for Dias Lake. Here is what has been measured.
- Eutrophic
- Impaired · Mercury
Dias Lake in Volusia County, Florida has water-quality measurements published by Florida DEP, shown here as reported. Water clarity: 3.3 ft visibility. Phosphorus: 31.4 µg/L.
Dias Lake is a productive, nutrient-rich eutrophic lake in Volusia County, Florida. Overall water quality is improving over recent sampling years. Compared to the 29 other monitored lakes in Volusia County, Dias Lake ranks #9 for water quality.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2025-02-11. Methodology: how these readings are compared.
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. Dias Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether Dias 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 Dias Lake
These are the measurements Florida DEP publishes for Dias 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 31.4 µg/L. TSI 57.
| 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 | 31.4µg/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. | 57 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Dias Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Dias Lake typically sits around 78°F at the surface in October. Summer average is about 87°F. Usually warmest in Aug (about 88°F) and coldest in Dec (about 66°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (66°F) to its warmest (88°F).
Typical surface water temperature by month, from 59 field readings (2010–2025) via the EPA Water Quality Portal. See the full Dias Lake water temperature breakdown →
Stays via Stay22
Stays near Dias Lake
Compare lakeside cabins, hotels, and vacation rentals near Dias Lake in Volusia 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 Dias Lake
Prices for Oct 16–18, 4 adults. Change dates on the map below.
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Planning a whole trip? See where to stay at Florida’s top lakes →
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Fishing Dias Lake
Water Quality Trend: Improving
Based on 5 years of monitoring (2020–2024).
Water clarity
Improving5 years
Phosphorus
Stable+0.08 µg/L/yr5 years
EPA Impairment Status
Dias Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Fish consumption.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit FL2667A · Official waterbody report
Nearby Lakes in Volusia County
Frequently asked questions about Dias Lake
Where is Dias Lake?
- Dias Lake is a lake in Volusia County, Florida. Its water-quality measurements are published by Florida DEP and shown on this page as reported.
What is the water quality of Dias Lake?
- Dias Lake in Volusia County, Florida has water-quality measurements published by Florida DEP, shown here as reported. Water clarity: 3.3 ft visibility. Phosphorus: 31.4 µg/L.
Is Dias Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Dias Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
What is the water temperature of Dias Lake?
- Dias Lake typically sits around 78°F at the surface in October, from 59 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
Explore Dias Lake across LakeQuality
Planning a trip around Fort Matanzas?
Dias Lake is about 38 miles from Fort Matanzas National Monument. Crowds there swing hard by season, so the month you pick changes both how busy the park is and what lodging costs.
Best time to visit Fort Matanzas →More lakes in Florida
Other Lakes in Florida
Eutrophic Lakes in Florida
Where this data comes from
62 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Submitting organization not recorded for these samples62 samples · 2020–2025
Monitoring station identifiers (1)
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