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LakeQuality

Monroe-Desbiens Lake

D
Grade D — Nutrient-rich
Nutrient-rich · #2 of 2 lakes in the county · 2.5 ft clear · Hypereutrophic · from F
Hypereutrophic

Monroe-Desbiens Lake in Monroe County, Florida has a water quality grade of D (Nutrient-rich). Water clarity: 2.5 ft visibility. Phosphorus: 267 µg/L.

Clarity
2.5 ft
Type
Hypereutrophic
Trend
Stable
Public access
Yes

Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Monroe-Desbiens Lake

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Monroe-Desbiens Lake is a highly nutrient-loaded hypereutrophic lake in Monroe County, Florida. Water quality is graded D based on 1 sampling years through 2024. Water clarity is declining over recent sampling years. Limited fish-species data available. Public access is available with 2 public boat landings. Compared to the 1 other monitored lakes in Monroe County, Monroe-Desbiens Lake ranks #2 for water quality.

Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2024-12-06. Grade methodology: LakeQuality methodology.

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Swimming Safety

Grade only

Elevated nutrients

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.

Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum

Get alerts for Monroe-Desbiens Lake

Water Quality Grade: D (Nutrient-rich)

Very murky, less than 2.5 ft of visibility. Phosphorus level: 267 µg/L. Trophic State Index: 74.

MetricValueGrade
Water Clarity (Secchi Depth)2.5 ftNot graded
Phosphorus267 µg/LPoor
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)74Hypereutrophic

Very high nutrients, dense algae, poor clarity

Where to stay near Monroe-Desbiens Lake

Compare lakeside cabins, hotels, and vacation rentals near Monroe-Desbiens Lake in Monroe 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Monroe-Desbiens Lake are listed below.

Top-rated places to stay near Monroe-Desbiens Lake

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

Recreation & Access

2
Boat Landings
Yes
Public Access
  • Stock Island Wayside Park Public Boat Ramp (Mile Marker 5)Public
  • Boyds Key WestSemi-private

Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps

Fishing Monroe-Desbiens Lake

Based on 4 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-0.2 m/yr2
Phosphorus Improving-6.15 µg/L/yr4
See year-by-year chart →

EPA Impairment Status

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

Causes of impairment

Algal growthMercuryMetals (other than mercury)

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

Source: EPA ATTAINS assessment unit FL6014B · Official waterbody report · Matched by proximity (1 km)

County Ranking

Ranked #2 of 2 lakes in Monroe County

Nearby Lakes With Higher Grades

Monroe-Desbiens Lake holds Grade D. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.

See full comparison →

Nearby Lakes in Monroe County

Frequently asked questions about Monroe-Desbiens Lake

Where is Monroe-Desbiens Lake?

Monroe-Desbiens Lake is a lake in Monroe County, Florida. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.

What is the water quality grade for Monroe-Desbiens Lake?

Monroe-Desbiens Lake in Monroe County, Florida has a water quality grade of D (Nutrient-rich). Water clarity: 2.5 ft visibility. Phosphorus: 267 µg/L.

Is Monroe-Desbiens Lake safe to swim in?

Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Monroe-Desbiens Lake has a water quality grade of D (Nutrient-rich). Always check local health department advisories before swimming.

Are there boat ramps on Monroe-Desbiens Lake?

Monroe-Desbiens Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Stock Island Wayside Park Public Boat Ramp (Mile Marker 5), Boyds Key West. Public access is listed as yes.

Where this data comes from

23 measurements from 1 monitoring station, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • FLORIDA LAKEWATCH21FLKWAT_WQX23 samples · 2020–2024
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

Named boat-access points from the USGS National Boat Ramps inventory