Kirwin Lake
Phillips County, Kansas10,640 acresView mapDirections
Nutrients and algae run above the regional average.
↓ down from C at the last regrade
- Eutrophic
- Impaired · Nutrients (phosphorus, nitrogen)
- #1 of 1 in the county
- 71 ft max depth
- Public access
- Limited data
Kirwin Lake in Phillips County, Kansas has a water quality grade of D (Nutrient-rich). Water clarity: 5.5 ft visibility. Phosphorus: 65.5 µg/L. Chlorophyll-a (algae): 16.1 µg/L. Surface area: 10640 acres.
- Clarity
- 5.5 ft
- Max depth
- ~71 ft est.
- Area
- 10,640 acres
- Type
- Eutrophic
- Phosphorus
- 65.5 µg/L
- Chlorophyll-a
- 16.1 µg/L
- Trend
- ↓ Declining
- Public access
- Yes
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Stays near Kirwin Lake
Compare lakeside cabins, hotels, and vacation rentals near Kirwin Lake in Phillips 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 Kirwin Lake are listed below.
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Kirwin Lake is a 10,640-acre productive, nutrient-rich eutrophic lake in Phillips County, Kansas with an estimated average depth of about 71 feet. Water quality is graded D based on 2 sampling years through 2016. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available with 2 public boat landings.
Source: EPA Water Quality Portal sampling records, KDHE, last sampled 2016-08-15. Grade methodology: LakeQuality methodology.
What Kirwin Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch2 documented ramps
- Big water10,640 acres
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 D is nutrients and algae, not a swimming clearance. Kirwin Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen), oxygen depletion (low DO). Check local advisories before you swim.
Water Quality Grade: D (Nutrient-rich)
Murky, only visible to about 5.5 ft. Phosphorus 65.5 µg/L. Chlorophyll-a 16.1 µg/L. TSI 58. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 5.5 ft | Not graded |
| Phosphorus | 65.5 µg/L | Poor |
| Chlorophyll-a (Algae) | 16.1 µg/L | Poor |
| Trophic State Index (TSI) | 58 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~71 ft est. |
| Average Depth | ~28 ft est. |
| Surface Area | 10,640 acres |
| Public Access | Yes |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Kansas has not published bathymetry for Kirwin Lake.
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.
Recreation & Access
- Kirwin National Wildlife Refuge - East Xavier RoadPublic
- Kirwin National Wildlife Refuge - Bluegill PointPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Kirwin Lake
Water Quality Trend: ↓ Declining
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -1.67 m/yr | 2 |
| Phosphorus | ↓ Declining | +33 µg/L/yr | 2 |
| Chlorophyll-a | ↓ Declining | +22.1 µg/L/yr | 2 |
Reservoir Info (USACE NID)
Kirwin Lake is a man-made reservoir impounded by the Kirwin Dam (completed 1955), built primarily for flood risk reduction on the North Fork Solomon River; earth-type dam, 169 ft tall and 12,646 ft long.
- Surface area
- 10,640 ac
- Normal storage
- 99,500 ac-ft
- Max storage
- 511,757 ac-ft
- Drainage area
- 1,367 sq mi
- Hazard class
- High
- Owner
- BUREAU OF RECLAMATION
All listed purposes: Flood Risk Reduction;Irrigation.
Source: USACE National Inventory of Dams, NID ID KS00022 · Operator website
EPA Impairment Status
Kirwin Lake 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-LM011001 · Official waterbody report
County Ranking
Ranked #1 of 1 lakes in Phillips County
Nearby Lakes in Phillips County
Frequently asked questions about Kirwin Lake
Where is Kirwin Lake?
- Kirwin Lake is a lake in Phillips County, Kansas. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Kirwin Lake?
- Kirwin Lake in Phillips County, Kansas has a water quality grade of D (Nutrient-rich). Water clarity: 5.5 ft visibility. Phosphorus: 65.5 µg/L. Chlorophyll-a (algae): 16.1 µg/L. Surface area: 10640 acres.
Is Kirwin Lake safe to swim in?
- The D is nutrients and algae, not a swimming clearance. Kirwin Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen), oxygen depletion (low DO). Check local advisories before you swim.
How deep is Kirwin Lake?
- No published bathymetric survey covers Kirwin Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 71 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 10640 acres.
Are there boat ramps on Kirwin Lake?
- Kirwin Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Kirwin National Wildlife Refuge - East Xavier Road, Kirwin National Wildlife Refuge - Bluegill Point. Public access is listed as yes.
Explore Kirwin Lake across LakeQuality
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Where this data comes from
12 measurements from 1 monitoring station, 2015–2016. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Kansas Department Of Health And Environment
21KAN001_WQX12 samples · 2015–2016
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)
Named boat-access points from the USGS National Boat Ramps inventory