Clay-Little Johnson Lake
Clay-Little Johnson Lake in Clay County, Florida has a water quality grade of B (Good). Water clarity: 5.7 ft visibility. Phosphorus: 16 µg/L.
- Clarity
- 5.7 ft
- Type
- Mesotrophic
- Trend
- ↑ Improving
Next lake in Clay County
Swipe left or right on this bar to open the next or previous lake.
Clay-Little Johnson Lake is a mesotrophic lake in Clay County, Florida. Water quality is graded B based on 1 sampling years through 2025. Overall water quality is improving over recent sampling years. Compared to the 16 other monitored lakes in Clay County, Clay-Little Johnson Lake ranks #5 for water quality.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2025-04-09. Grade methodology: LakeQuality methodology.
Watch Clay-Little Johnson Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Grade onlyLow algae
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.
Good for swimming, clear water with low algae levels
Water Quality Grade: B (Good)
Murky, only visible to about 5.7 ft. Phosphorus level: 16 µg/L. Trophic State Index: 48.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 5.7 ft | Not graded |
| Phosphorus | 16 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 48 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Clay-Little Johnson Lake
Compare lakeside cabins, hotels, and vacation rentals near Clay-Little Johnson Lake in Clay 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 Clay-Little Johnson Lake
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 →
Fishing Clay-Little Johnson Lake
Water Quality Trend: ↑ Improving
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.4 m/yr | 5 |
| Phosphorus | ↑ Improving | -0.6 µg/L/yr | 5 |
EPA Impairment Status
Clay-Little Johnson Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 4C).
Causes of impairment
Source: EPA ATTAINS assessment unit FL2528B · Official waterbody report · Matched by proximity (1.8 km)
County Ranking
Ranked #5 of 17 lakes in Clay County
Nearby Lakes in Clay County
Frequently asked questions about Clay-Little Johnson Lake
Where is Clay-Little Johnson Lake?
- Clay-Little Johnson Lake is a lake in Clay County, Florida. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Clay-Little Johnson Lake?
- Clay-Little Johnson Lake in Clay County, Florida has a water quality grade of B (Good). Water clarity: 5.7 ft visibility. Phosphorus: 16 µg/L.
Is Clay-Little Johnson Lake safe to swim in?
- Good for swimming, clear water with low algae levels. Clay-Little Johnson Lake has a water quality grade of B (Good). Always check local health department advisories before swimming.
Explore Clay-Little Johnson Lake across LakeQuality
Planning a trip around Castillo de San Marcos?
Clay-Little Johnson Lake is about 38 miles from Castillo de San Marcos 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 Castillo de San Marcos →More Florida Lake Rankings
Other Grade B Lakes in Florida
Mesotrophic Lakes in Florida
Where this data comes from
252 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_WQX252 samples · 2020–2025
Monitoring station identifiers (3)
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