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LakeQuality

Lake Grady

NR
Not yet rated
2 ft clear · Eutrophic · 120 acres
Limited DataEutrophic

Lake Grady in Hillsborough County, Florida is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 2 ft visibility. Phosphorus: 110 µg/L. Surface area: 120 acres.

Clarity
2 ft
Area
120 acres
Trend
Declining

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Why Lake Grady has no grade

We grade a lake only when the monitoring record supports a letter: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Lake Grady, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). Sampling here has recorded water clarity and phosphorus, but not algae (chlorophyll-a).

Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.

Sampling is run by FDEP and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.

Lake Grady is a 120-acre lake in Hillsborough County, Florida. Overall water quality is declining over recent sampling years.

Source: EPA Water Quality Portal sampling records, FDEP, last sampled 2025-07-15. Grade methodology: LakeQuality methodology.

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Swimming Safety

Not rated

Bacteria advisory

Not rated for swimming — there is not enough monitoring data to judge this lake

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Water quality measurements for Lake Grady

These readings exist but are not enough for an A–F grade — see why.

Very murky, less than 2 ft of visibility. Phosphorus level: 110 µg/L. Trophic State Index: 70.

MetricValueGrade
Water Clarity (Secchi Depth)2 ftNot graded
Phosphorus110 µg/LNot graded
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)70Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Lake Grady

Compare lakeside cabins, hotels, and vacation rentals near Lake Grady 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.

Top-rated places to stay near Lake Grady

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

Lake Details

CharacteristicValue
Surface Area120 acres

No bathymetric survey has been published for Lake Grady, so its depth is not documented here.

Fishing Lake Grady

Based on 3 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-0.543 m/yr3
Phosphorus Declining+27.93 µg/L/yr3

Reservoir Info (USACE NID)

Lake Grady 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

EPA Impairment Status

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

Causes of impairment

Pathogens (E. coli, fecal)

Source: EPA ATTAINS assessment unit FL1660 · Official waterbody report · Matched by proximity (1.37 km)

Regulated Pollution Sources Nearby

1 EPA-permitted facility operate within about 5 miles of Lake Grady under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.

  • Rice Creek Wwtf
    Riverview · 2.8 mi away · NPDES FL0122076
    Recent violation

Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.

Graded lakes near Lake Grady

Lake Grady has no grade, but these lakes within a short drive do.

Nearby Lakes in Hillsborough County

Frequently asked questions about Lake Grady

Where is Lake Grady?

Lake Grady is a lake in Hillsborough County, Florida. LakeQuality has not rated this lake (UNRATED) — no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years).

What is the water quality grade for Lake Grady?

Lake Grady in Hillsborough County, Florida is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 2 ft visibility. Phosphorus: 110 µg/L. Surface area: 120 acres.

Is Lake Grady safe to swim in?

Not rated for swimming — there is not enough monitoring data to judge this lake. Lake Grady is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.

Where this data comes from

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

Collected and reported by

  • Submitting organization not recorded for these samples5 samples · 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

Regulated discharger data from EPA ECHO (ICIS-NPDES)