Pomona Lake
Osage County, Kansas4,000 acresView mapDirections
Nutrients and algae run well above the regional average.
↓ down from D at the last regrade
- Hypereutrophic
- Impaired · Nutrients (phosphorus, nitrogen)
- #5 of 5 in the county
- 51 ft max depth
- Public access
- Limited data
Pomona Lake in Osage County, Kansas has a water quality grade of F (Algae-prone). Water clarity: 2.9 ft visibility. Phosphorus: 67 µg/L. Chlorophyll-a (algae): 31.5 µg/L. Surface area: 4000 acres.
- Clarity
- 2.9 ft
- Max depth
- ~51 ft est.
- Area
- 4,000 acres
- Type
- Hypereutrophic
- Phosphorus
- 67 µg/L
- Chlorophyll-a
- 31.5 µg/L
- Trend
- → Stable
- Public access
- Yes
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Stays near Pomona Lake
Compare lakeside cabins, hotels, and vacation rentals near Pomona Lake in Osage 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 Pomona Lake are listed below.
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Watch Pomona Lake’s letter
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Pomona Lake is a 4,000-acre highly nutrient-loaded hypereutrophic lake in Osage County, Kansas with an estimated average depth of about 51 feet. Water quality is graded F based on 2 sampling years through 2017. Water clarity is declining over recent sampling years. Limited fish-species data available. Public access is available with 7 public boat landings. Compared to the 4 other monitored lakes in Osage County, Pomona Lake ranks #5 for water quality.
Source: EPA Water Quality Portal sampling records, KDHE, last sampled 2017-08-02. Grade methodology: LakeQuality methodology.
What Pomona Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch7 documented ramps
- Big water4,000 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 F is nutrients and algae, not a swimming clearance. Pomona Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen), sediment / turbidity. Check local advisories before you swim.
Water Quality Grade: F (Algae-prone)
Very murky, less than 2.9 ft of visibility. Phosphorus 67 µg/L. Chlorophyll-a 31.5 µg/L. TSI 64. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.9 ft | Not graded |
| Phosphorus | 67 µg/L | Poor |
| Chlorophyll-a (Algae) | 31.5 µg/L | Poor |
| Trophic State Index (TSI) | 64 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Current Conditions
USGS snapshot Sep 7, 2026, 3:45 PM from gauge 06912490 (POMONA LK NR QUENEMO, KS). Station page ↗ — a live reading replaces this snapshot when the gauge responds. Missing live data is not an all-clear.
→ Pomona Lake water level: the live USGS gauge reading
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~51 ft est. |
| Surface Area | 4,000 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 Pomona 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
- Pomona Lake MarinaPublic
- Pomona Lake-Red OakPublic
- Pomona Lake-Cedar WindPublic
- Pomona Lake-E 229th StreetPublic
- Dam SitePublic
- Addams GrovePublic
Showing 6 of 7 documented landings from the USGS National Boat Ramps inventory.
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Pomona Lake
Water Quality Trend: → Stable
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.06 m/yr | 2 |
| Phosphorus | ↑ Improving | -5.67 µg/L/yr | 2 |
| Chlorophyll-a | → Stable | -0.5 µg/L/yr | 2 |
Reservoir Info (USACE NID)
Pomona Lake is a man-made reservoir impounded by the Pomona Dam (completed 1963), built primarily for flood risk reduction on the Hundred Ten Mile Creek; rockfill-type dam, 111 ft tall and 7,750 ft long.
- Surface area
- 4,000 ac
- Normal storage
- 70,600 ac-ft
- Max storage
- 254,600 ac-ft
- Drainage area
- 322 sq mi
- Hazard class
- High
- Owner
- USACE - Kansas City District
All listed purposes: Flood Risk Reduction;Other;Fish and Wildlife Pond;Recreation.
Source: USACE National Inventory of Dams, NID ID KS00010 · Operator website
EPA Impairment Status
Pomona 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-LM028001 · Official waterbody report
County Ranking
Ranked #5 of 5 lakes in Osage County
Nearby Lakes in Osage County
Frequently asked questions about Pomona Lake
Where is Pomona Lake?
- Pomona Lake is a lake in Osage County, Kansas. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Pomona Lake?
- Pomona Lake in Osage County, Kansas has a water quality grade of F (Algae-prone). Water clarity: 2.9 ft visibility. Phosphorus: 67 µg/L. Chlorophyll-a (algae): 31.5 µg/L. Surface area: 4000 acres.
Is Pomona Lake safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Pomona Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen), sediment / turbidity. Check local advisories before you swim.
How deep is Pomona Lake?
- No published bathymetric survey covers Pomona Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 51 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 4000 acres.
What is the water level at Pomona Lake?
- The USGS snapshot on this page for Pomona Lake is 973.88 ft of water-surface elevation, recorded Sep 7, 2026, 3:45 PM at gauge 06912490. Current Conditions hydrates a live NWIS reading from that same station when the gauge responds. A missed live fetch is not an all-clear.
Are there boat ramps on Pomona Lake?
- Pomona Lake has 7 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Pomona Lake Marina, Pomona Lake-Red Oak, Pomona Lake-Cedar Wind, Pomona Lake-E 229th Street, among others. Public access is listed as yes.
Explore Pomona Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
Species activity outlook by water temperature and season
Where to stay at Kansas's top lakes, each with its grade
Very high nutrients, dense algae, poor clarity
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Where this data comes from
11 measurements from 1 monitoring station, 2014–2017. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Kansas Department Of Health And Environment
21KAN001_WQX11 samples · 2014–2017
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