Lake Keomah Beach
Mahaska County, IowaView mapDirections
No nutrient or algae sampling on record from Iowa DNR for this lake.
- Impaired · Algal growth
- Public access
- Limited data
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Answers come straight from the public measurements and survey records on this page.
Lake Keomah Beach in Mahaska County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported.
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Lake Keomah Beach is a lake in Mahaska County, Iowa. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2024-05-29. Grade methodology: LakeQuality methodology.
What Lake Keomah Beach is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
Swimming conditions
No readingBacteria advisory
Based on E. coli testing, Lake Keomah Beach routinely exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 25% of 100 samples across 7 seasons.
This is a historical summary of past testing, not a current condition — bacteria levels change quickly, especially after rain. Always check Iowa’s current beach and health-department advisories before swimming.
Whether Lake Keomah Beach is safe to swim in today is a call for the Iowa Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Lake Keomah Beach
These are the measurements Iowa DNR publishes for Lake Keomah Beach, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data.
| Metric | Value | EPA condition class |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples |
Recreation & Access
- Lake Keomah State ParkPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Lake Keomah Beach
Water Quality Trend: ↑ Improving
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.006 m/yr | 4 |
| Phosphorus | ↑ Improving | -28 µg/L/yr | 3 |
| Chlorophyll-a | ↑ Improving | -3.56 µg/L/yr | 4 |
EPA Impairment Status
Lake Keomah Beach is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit IA 03-SSK-930 · Official waterbody report · Matched by proximity (0.24 km)
Nearby Lakes in Mahaska County
Frequently asked questions about Lake Keomah Beach
Where is Lake Keomah Beach?
- Lake Keomah Beach is a lake in Mahaska County, Iowa. Its water-quality measurements are published by Iowa DNR and shown on this page as reported.
What is the water quality of Lake Keomah Beach?
- Lake Keomah Beach in Mahaska County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported.
Is Lake Keomah Beach safe to swim in?
- Based on E. coli testing, Lake Keomah Beach routinely exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 25% of 100 samples across 7 seasons. That is a historical summary of past bacteria testing, not a current reading and not a swimming clearance. Bacteria levels can spike quickly after heavy rain, so whether Lake Keomah Beach is safe to swim in today is a call for Iowa's water agency and the county health department; check their current beach advisories before you swim.
Are there boat ramps on Lake Keomah Beach?
- Lake Keomah Beach has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lake Keomah State Park. Public access is listed as yes.
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Where this data comes from
28 measurements from 1 monitoring station, 2021–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Iowa DNR Surface Water Monitoring Data
21IOWA_WQX28 samples · 2021–2024
Analytical methods
- 2130 B ~ Nephelometric Method
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
Named boat-access points from the USGS National Boat Ramps inventory