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LakeQuality

Lake Butner

Granville County, North Carolina340 acresView mapDirections

D
Nutrient-rich

Nutrients and algae run above the regional average.

↓ down from B at the last regrade

Water temp
No reading
No gauge
Clarity
5.4 ft
Secchi · sampled 2025
Level
No reading
No gauge
Trend
Stable
2 years of samples
  • Eutrophic
  • #1 of 3 in the county
  • 46 ft max depth

Lake Butner in Granville County, North Carolina has a water quality grade of D (Nutrient-rich). Water clarity: 5.4 ft visibility. Phosphorus: 40 µg/L. Chlorophyll-a (algae): 11 µg/L. Surface area: 340 acres.

Clarity
5.4 ft
Max depth
~46 ft est.
Area
340 acres
Type
Eutrophic
Trend
Stable
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Stays via Stay22

Stays near Lake Butner

Compare lakeside cabins, hotels, and vacation rentals near Lake Butner in Granville County, North Carolina — 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 Lake Butner are listed below.

Top-rated places to stay near Lake Butner

Prices for Sep 4–6, 4 adults. Change dates on the map below.

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Watch Lake Butner’s letter

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Lake Butner is a 340-acre productive, nutrient-rich eutrophic lake in Granville County, North Carolina with an estimated average depth of about 46 feet. Water quality is graded D based on 2 sampling years through 2025. Phosphorus level is declining over recent sampling years. Compared to the 2 other monitored lakes in Granville County, Lake Butner ranks #1 for water quality.

Source: EPA Water Quality Portal sampling records, NCDEQ, last sampled 2025-09-10. Grade methodology: LakeQuality methodology.

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.

The D is nutrients and algae, not a swimming clearance. Lake Butner is listed impaired under Clean Water Act §303(d) (IR 5) for impaired biota (cause unknown), metals (other than mercury). Check local advisories before you swim.

Get alerts for Lake Butner

Water Quality Grade: D (Nutrient-rich)

Murky, only visible to about 5.4 ft. Phosphorus 40 µg/L. Chlorophyll-a 11 µg/L. TSI 55. The letter is not a swimming clearance.

MetricValueGrade
Water Clarity (Secchi Depth)5.4 ftNot graded
Phosphorus40 µg/LPoor
Chlorophyll-a (Algae)11 µg/LFair
Trophic State Index (TSI)55Eutrophic

High nutrients, frequent algae, reduced clarity

Lake Details

CharacteristicValue
Maximum Depth~46 ft est.
Average Depth~17 ft est.
Surface Area340 acres

Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. North Carolina has not published bathymetry for Lake Butner.

Lake Size & Watershed

Watershed (drainage) area
29 sq mi
Shoreline
8 mi
Elevation
377 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.

Fishing Lake Butner

Based on 2 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Phosphorus Declining+6 µg/L/yr2
Chlorophyll-a Improving-1.2 µg/L/yr2

Reservoir Info (USACE NID)

Lake Butner is a man-made reservoir impounded by the Lake Butner Dam, built primarily for recreation on the Knap of Reeds Creek; earth-type dam, 80 ft tall and 550 ft long.

Surface area
340 ac
Normal storage
9,000 ac-ft
Max storage
10,800 ac-ft
Drainage area
28.67 sq mi
Hazard class
High
Owner
NC Department of Agriculture & Consumer Services

All listed purposes: Recreation;Water Supply.

Source: USACE National Inventory of Dams, NID ID NC01008 · Operator website

EPA Impairment Status

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

Causes of impairment

Impaired biota (cause unknown)Metals (other than mercury)

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

Source: EPA ATTAINS assessment unit NC27-4-(6) · Official waterbody report · Matched by proximity (1.33 km)

County Ranking

Ranked #1 of 3 lakes in Granville County

Nearby Lakes in Granville County

Frequently asked questions about Lake Butner

Where is Lake Butner?

Lake Butner is a lake in Granville County, North Carolina. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.

What is the water quality grade for Lake Butner?

Lake Butner in Granville County, North Carolina has a water quality grade of D (Nutrient-rich). Water clarity: 5.4 ft visibility. Phosphorus: 40 µg/L. Chlorophyll-a (algae): 11 µg/L. Surface area: 340 acres.

Is Lake Butner safe to swim in?

The D is nutrients and algae, not a swimming clearance. Lake Butner is listed impaired under Clean Water Act §303(d) (IR 5) for impaired biota (cause unknown), metals (other than mercury). Check local advisories before you swim.

How deep is Lake Butner?

No published bathymetric survey covers Lake Butner, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 46 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 340 acres.

Where this data comes from

73 measurements from 2 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • North Carolina Dept of Environmental Quality NCDEQ-DWR WQX21NC03WQ73 samples · 2020–2025

Analytical methods

  • WSSSOP
  • Phosphorus by Colorimetry
  • 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
  • 2130 B ~ Nephelometric Method
Monitoring station identifiers (2)

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

Lake size & watershed from HydroLAKES (HydroSHEDS)