Garnett Lake
Anderson County, Kansas45 acresView mapDirections
KDHE publishes the water-quality measurements for Garnett Lake. Here is what has been measured.
- Impaired · Nutrients (phosphorus, nitrogen)
- 22 ft max depth
- Limited data
Garnett Lake in Anderson County, Kansas has water-quality measurements published by KDHE, shown here as reported. Water clarity: 2.4 ft visibility. Phosphorus: 69.5 µg/L. Chlorophyll-a (algae): 160 µg/L. Surface area: 45 acres.
Garnett Lake is a 45-acre lake in Anderson County, Kansas with an estimated average depth of about 22 feet.
Source: EPA Water Quality Portal sampling records, KDHE, last sampled 2017-08-14. Methodology: how these readings are compared.
Garnett Lake covers about 45 acres in Anderson County. For a place on the water, look through cabin and lake-house rentals near Garnett Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
Swimming conditions
No readingRecreation use not supported
Nutrient and algae readings are not a swimming clearance. Garnett Lake is listed impaired under Clean Water Act §303(d) (IR 5) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Garnett Lake is safe to swim in today is a call for the Kansas Department of Health and Environment and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Garnett Lake
These are the measurements KDHE publishes for Garnett Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 2.4 ft of visibility. Phosphorus 69.5 µg/L. Chlorophyll-a 160 µg/L. TSI 70.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 2.4ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 69.5µg/L | Measured, not scored The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. |
| Chlorophyll-a (algae) | 160µg/L | Measured, not scored The green pigment in algae — a direct measure of how much algae is in the water. |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 70 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Garnett Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
~22 ft est.
Surface area
45 acres
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Kansas has not published bathymetry for Garnett Lake.
Lake Size & Watershed
Watershed (drainage) area
2 sq mi
HydroLAKES / HydroSHEDS
Shoreline
1.4 mi
HydroLAKES / HydroSHEDS
Elevation
1,010 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.
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Stays near Garnett Lake
Compare lakeside cabins, hotels, and vacation rentals near Garnett Lake in Anderson County, Kansas — 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.
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Fishing Garnett Lake
Reservoir Info (USACE NID)
Garnett Lake is a man-made reservoir impounded by the Garnett City Dam (completed 1935), built primarily for recreation on the Pottawatomie Creek-Tr; earth-type dam, 60 ft tall and 1,100 ft long.
- Surface area
- 45 ac
- Normal storage
- 840 ac-ft
- Max storage
- 920 ac-ft
- Drainage area
- 2.11 sq mi
- Hazard class
- Low
- Owner
- GARNETT, CITY OF
All listed purposes: Recreation;Water Supply.
Source: USACE National Inventory of Dams, NID ID KS00202 · Operator website
EPA Impairment Status
Garnett Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Drinking water, Aquatic life, Recreation.
Source: EPA ATTAINS assessment unit KS-LM040601 · Official waterbody report
Nearby Lakes in Anderson County
Frequently asked questions about Garnett Lake
Where is Garnett Lake?
- Garnett Lake is a lake in Anderson County, Kansas. Its water-quality measurements are published by KDHE and shown on this page as reported.
What is the water quality of Garnett Lake?
- Garnett Lake in Anderson County, Kansas has water-quality measurements published by KDHE, shown here as reported. Water clarity: 2.4 ft visibility. Phosphorus: 69.5 µg/L. Chlorophyll-a (algae): 160 µg/L. Surface area: 45 acres.
Is Garnett Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Garnett Lake is listed impaired under Clean Water Act §303(d) (IR 5) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
How deep is Garnett Lake?
- No published bathymetric survey covers Garnett Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 22 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 45 acres.
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Where this data comes from
5 measurements from 1 monitoring station, 2017. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Kansas Department Of Health And Environment
21KAN001_WQX5 samples · 2017
Analytical methods
- Depth, Secchi disk depth
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (1)
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
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)