Lake Thom-A-Lex
Davidson County, North Carolina650 acresView mapDirections
NC DEQ publishes the water-quality measurements for Lake Thom-A-Lex. Here is what has been measured.
- Hypereutrophic
- 42 ft max depth
- Limited data
Lake Thom-A-Lex in Davidson County, North Carolina has water-quality measurements published by NC DEQ, shown here as reported. Phosphorus: 55 µg/L. Chlorophyll-a (algae): 40 µg/L. Surface area: 650 acres.
Lake Thom-A-Lex is a 650-acre highly nutrient-loaded hypereutrophic lake in Davidson County, North Carolina with an estimated average depth of about 42 feet. Compared to the 1 other monitored lakes in Davidson County, Lake Thom-A-Lex ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, NCDEQ, last sampled 2021-09-28. Methodology: how these readings are compared.
Swimming conditions
Readings onlyLimited data
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Lake Thom-A-Lex is safe to swim in today is a call for the North Carolina Department of Environmental Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Lake Thom-A-Lex
These are the measurements NC DEQ publishes for Lake Thom-A-Lex, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data. Phosphorus 55 µg/L. Chlorophyll-a 40 µg/L. TSI 64.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | No reading How deep a black-and-white disk stays visible from the surface. Higher is clearer. | |
| Total phosphorus | 55µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 40µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 64 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Lake Thom-A-Lex
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
~42 ft est.
Surface area
650 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 Thom-A-Lex.
Lake Size & Watershed
Watershed (drainage) area
70 sq mi
HydroLAKES / HydroSHEDS
Shoreline
8.7 mi
HydroLAKES / HydroSHEDS
Elevation
702 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.
Stays via Stay22
Stays near Lake Thom-A-Lex
Compare lakeside cabins, hotels, and vacation rentals near Lake Thom-A-Lex in Davidson 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 readings cover nutrients and algae, not lodging. Cabins and rentals around Lake Thom-A-Lex are listed below.
Top-rated places to stay near Lake Thom-A-Lex
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Fishing Lake Thom-A-Lex
Reservoir Info (USACE NID)
Lake Thom-A-Lex is a man-made reservoir impounded by the Lake Thom-A-Lex Dam (completed 1957), built primarily for water supply on the Abbotts Creek; earth-type dam, 43 ft tall and 635 ft long.
- Surface area
- 650 ac
- Normal storage
- 8,320 ac-ft
- Max storage
- 11,180 ac-ft
- Drainage area
- 69.71 sq mi
- Hazard class
- High
- Owner
- City of Lexington
Source: USACE National Inventory of Dams, NID ID NC00178 · Operator website
Nearby Lakes in Davidson County
Frequently asked questions about Lake Thom-A-Lex
Where is Lake Thom-A-Lex?
- Lake Thom-A-Lex is a lake in Davidson County, North Carolina. Its water-quality measurements are published by NC DEQ and shown on this page as reported.
What is the water quality of Lake Thom-A-Lex?
- Lake Thom-A-Lex in Davidson County, North Carolina has water-quality measurements published by NC DEQ, shown here as reported. Phosphorus: 55 µg/L. Chlorophyll-a (algae): 40 µg/L. Surface area: 650 acres.
Is Lake Thom-A-Lex safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Lake Thom-A-Lex?
- No published bathymetric survey covers Lake Thom-A-Lex, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 42 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 650 acres.
Explore Lake Thom-A-Lex across LakeQuality
5.6 mi away · cable-pulled, no boat wake
Species activity outlook by water temperature and season
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Where this data comes from
30 measurements from 2 monitoring stations, 2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- North Carolina Dept of Environmental Quality NCDEQ-DWR WQX
21NC03WQ30 samples · 2021
Analytical methods
- Phosphorus by Colorimetry
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- 2130 B ~ Nephelometric Method
Monitoring station identifiers (2)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Lake size & watershed from HydroLAKES (HydroSHEDS)