Hillsborough-Grady Lake
Hillsborough-Grady Lake in Hillsborough County, Florida has a water quality grade of D (Nutrient-rich). Water clarity: 1.8 ft visibility. Phosphorus: 107 µg/L. Surface area: 120 acres.
- Clarity
- 1.8 ft
- Area
- 120 acres
- Type
- Hypereutrophic
- Trend
- ↓ Declining
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Hillsborough-Grady Lake →
Next lake in Hillsborough County
Swipe left or right on this bar to open the next or previous lake.
Hillsborough-Grady Lake is a 120-acre highly nutrient-loaded hypereutrophic lake in Hillsborough County, Florida. Water quality is graded D based on 1 sampling years through 2024. Overall water quality is declining over recent sampling years. Compared to the 123 other monitored lakes in Hillsborough County, Hillsborough-Grady Lake ranks #106 for water quality.
Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2024-03-07. Grade methodology: LakeQuality methodology.
Watch Hillsborough-Grady Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Grade onlyBacteria advisory
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
Water Quality Grade: D (Nutrient-rich)
Very murky, less than 1.8 ft of visibility. Phosphorus level: 107 µg/L. Trophic State Index: 70.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.8 ft | Not graded |
| Phosphorus | 107 µg/L | Poor |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 70 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Where to stay near Hillsborough-Grady Lake
Compare lakeside cabins, hotels, and vacation rentals near Hillsborough-Grady Lake in Hillsborough 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 Hillsborough-Grady Lake are listed below.
Top-rated places to stay near Hillsborough-Grady 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 →
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 120 acres |
No bathymetric survey has been published for Hillsborough-Grady Lake, so its depth is not documented here.
Fishing Hillsborough-Grady Lake
Water Quality Trend: ↓ Declining
Based on 3 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.543 m/yr | 3 |
| Phosphorus | ↓ Declining | +27.93 µg/L/yr | 3 |
Reservoir Info (USACE NID)
Hillsborough-Grady Lake is a man-made reservoir impounded by the Shadow Run Dam (completed 1969), built primarily for recreation on the Bell Creek; earth-type dam, 30 ft tall and 1,015 ft long.
- Surface area
- 120 ac
- Normal storage
- 750 ac-ft
- Max storage
- 3,119 ac-ft
- Drainage area
- 17.43 sq mi
- Hazard class
- High
- Owner
- SHADOW RUN DAM CORP
All listed purposes: Recreation;Fish and Wildlife Pond.
Source: USACE National Inventory of Dams, NID ID FL00176 · Operator website · Matched by proximity (0.34 km)
EPA Impairment Status
Hillsborough-Grady Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit FL1660 · Official waterbody report · Matched by proximity (1.75 km)
County Ranking
Ranked #106 of 124 lakes in Hillsborough County
Nearby Lakes in Hillsborough County
Frequently asked questions about Hillsborough-Grady Lake
Where is Hillsborough-Grady Lake?
- Hillsborough-Grady Lake is a lake in Hillsborough County, Florida. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Hillsborough-Grady Lake?
- Hillsborough-Grady Lake in Hillsborough County, Florida has a water quality grade of D (Nutrient-rich). Water clarity: 1.8 ft visibility. Phosphorus: 107 µg/L. Surface area: 120 acres.
Is Hillsborough-Grady 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. Hillsborough-Grady Lake has a water quality grade of D (Nutrient-rich). Always check local health department advisories before swimming.
Explore Hillsborough-Grady Lake across LakeQuality
More Florida Lake Rankings
Other Grade D Lakes in Florida
Hypereutrophic Lakes in Florida
Where this data comes from
88 measurements from 3 monitoring stations, 2023–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- FLORIDA LAKEWATCH
21FLKWAT_WQX88 samples · 2023–2024
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