Lake Afton
Sedgwick County, Kansas238 acresView mapDirections
Nutrients and algae run well above the regional average.
↓ down from D at the last regrade
- Hypereutrophic
- Impaired · Nutrients (phosphorus, nitrogen)
- #3 of 3 in the county
- 52 ft max depth
- Limited data
Lake Afton in Sedgwick County, Kansas has a water quality grade of F (Algae-prone). Water clarity: 1.7 ft visibility. Phosphorus: 170 µg/L. Chlorophyll-a (algae): 90.1 µg/L. Surface area: 238 acres.
- Clarity
- 1.7 ft
- Max depth
- ~52 ft est.
- Area
- 238 acres
- Type
- Hypereutrophic
- Phosphorus
- 170 µg/L
- Chlorophyll-a
- 90.1 µg/L
- Trend
- ↓ Declining
Stays via Stay22
Stays near Lake Afton
Compare lakeside cabins, hotels, and vacation rentals near Lake Afton in Sedgwick 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Lake Afton are listed below.
Top-rated places to stay near Lake Afton
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Watch Lake Afton’s letter
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Lake Afton is a 238-acre highly nutrient-loaded hypereutrophic lake in Sedgwick County, Kansas with an estimated average depth of about 52 feet. Water quality is graded F based on 1 sampling years through 2018. Overall water quality is declining over recent sampling years. Compared to the 2 other monitored lakes in Sedgwick County, Lake Afton ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, KDHE, last sampled 2018-08-22. Grade methodology: LakeQuality methodology.
Swimming Safety
Grade onlyLimited data
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 F is nutrients and algae, not a swimming clearance. Lake Afton is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Water Quality Grade: F (Algae-prone)
Very murky, less than 1.7 ft of visibility. Phosphorus 170 µg/L. Chlorophyll-a 90.1 µg/L. TSI 74. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.7 ft | Not graded |
| Phosphorus | 170 µg/L | Not graded |
| Chlorophyll-a (Algae) | 90.1 µg/L | Poor |
| Trophic State Index (TSI) | 74 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~52 ft est. |
| Average Depth | ~10 ft est. |
| Surface Area | 238 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 Lake Afton.
Lake Size & Watershed
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 Afton
Water Quality Trend: ↓ Declining
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.068 m/yr | 2 |
| Phosphorus | ↑ Improving | -9.17 µg/L/yr | 2 |
| Chlorophyll-a | ↓ Declining | +27.23 µg/L/yr | 2 |
Reservoir Info (USACE NID)
Lake Afton is a man-made reservoir impounded by the Lake Afton Dam (completed 1942), built primarily for recreation on the Clearwater Creek-Tr; earth-type dam, 55 ft tall and 4,037 ft long.
- Surface area
- 238 ac
- Normal storage
- 2,976 ac-ft
- Max storage
- 6,146 ac-ft
- Drainage area
- 10.28 sq mi
- Hazard class
- High
- Owner
- SEDGWICK COUNTY
Source: USACE National Inventory of Dams, NID ID KS02553 · Operator website
EPA Impairment Status
Lake Afton is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit KS-LM049201 · Official waterbody report
County Ranking
Ranked #3 of 3 lakes in Sedgwick County
Nearby Lakes With Higher Grades
Lake Afton holds Grade F. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.
Nearby Lakes in Sedgwick County
Frequently asked questions about Lake Afton
Where is Lake Afton?
- Lake Afton is a lake in Sedgwick County, Kansas. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Lake Afton?
- Lake Afton in Sedgwick County, Kansas has a water quality grade of F (Algae-prone). Water clarity: 1.7 ft visibility. Phosphorus: 170 µg/L. Chlorophyll-a (algae): 90.1 µg/L. Surface area: 238 acres.
Is Lake Afton safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Lake Afton is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
How deep is Lake Afton?
- No published bathymetric survey covers Lake Afton, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 52 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 238 acres.
Explore Lake Afton across LakeQuality
More Kansas Lake Rankings
Other Grade F Lakes in Kansas
Hypereutrophic Lakes in Kansas
Where this data comes from
8 measurements from 1 monitoring station, 2012–2018. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Kansas Department Of Health And Environment
21KAN001_WQX8 samples · 2012–2018
Analytical methods
- Depth, Secchi disk depth
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
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
Lake size & watershed from HydroLAKES (HydroSHEDS)