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LakeQuality

Oyster Lake Causeway

C
Grade C — Fair
Fair · #81 of 84 lakes in the county · 3 ft clear · Eutrophic
Eutrophic

Oyster Lake Causeway in Walton County, Florida has a water quality grade of C (Fair). Water clarity: 3 ft visibility. Phosphorus: 59 µg/L.

Clarity
3 ft
Typical in August
88°F
Type
Eutrophic
Trend
Improving

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Oyster Lake Causeway is a productive, nutrient-rich eutrophic lake in Walton County, Florida. Water quality is graded C based on 1 sampling years through 2025. Overall water quality is improving over recent sampling years. Compared to the 83 other monitored lakes in Walton County, Oyster Lake Causeway ranks #81 for water quality.

Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2025-02-05. Grade methodology: LakeQuality methodology.

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Swimming Safety

Grade only

Moderate

Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.

Generally safe for swimming, moderate water quality

Get alerts for Oyster Lake Causeway

Water Quality Grade: C (Fair)

Very murky, less than 3 ft of visibility. Phosphorus level: 59 µg/L. Trophic State Index: 62.

MetricValueGrade
Water Clarity (Secchi Depth)3 ftNot graded
Phosphorus59 µg/LFair
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)62Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Oyster Lake Causeway

Compare lakeside cabins, hotels, and vacation rentals near Oyster Lake Causeway in Walton 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 Oyster Lake Causeway

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

Planning a whole trip? See where to stay at Florida’s top lakes →

Water Temperature

Oyster Lake Causeway typically sits around 88°F at the surface in August. Summer average is about 87°F. Usually warmest in Jul (about 88°F) and coldest in Jan (about 60°F). These are typical values by month — not a live reading.

Jan
60°
Feb
63°
Mar
69°
Apr
75°
May
78°
Jun
86°
Jul
88°
Aug
88°
Sep
82°
Oct
76°
Nov
67°
Dec
62°

Typical surface water temperature by month, from 332 field readings (20102025) via the EPA Water Quality Portal. See the full Oyster Lake Causeway water temperature breakdown →

Fishing Oyster Lake Causeway

Based on 5 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Stable+0.05 m/yr5
Phosphorus Improving-0.55 µg/L/yr5
See year-by-year chart →

EPA Impairment Status

Oyster Lake Causeway is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).

Causes of impairment

Algal growthMercuryOxygen depletion (low DO)

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit FL959C · Official waterbody report · Matched by proximity (0.17 km)

County Ranking

Ranked #81 of 84 lakes in Walton County

Nearby Lakes With Higher Grades

Oyster Lake Causeway holds Grade C. 3 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.

See full comparison →

Nearby Lakes in Walton County

Frequently asked questions about Oyster Lake Causeway

Where is Oyster Lake Causeway?

Oyster Lake Causeway is a lake in Walton County, Florida. LakeQuality grades it C for nutrients and algae. The letter is not a swimming clearance.

What is the water quality grade for Oyster Lake Causeway?

Oyster Lake Causeway in Walton County, Florida has a water quality grade of C (Fair). Water clarity: 3 ft visibility. Phosphorus: 59 µg/L.

Is Oyster Lake Causeway safe to swim in?

Generally safe for swimming, moderate water quality. Oyster Lake Causeway has a water quality grade of C (Fair). Always check local health department advisories before swimming.

What is the water temperature of Oyster Lake Causeway?

Oyster Lake Causeway typically sits around 88°F at the surface in August, from 332 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.

Where this data comes from

114 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • CHOCTAWHATCHEE BASIN ALLIANCE21FLCBA_WQX114 samples · 2020–2025
Monitoring station identifiers (1)

Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.

Other records on this page

Impairment status from EPA ATTAINS 303(d) database