Lake Ahquabi is a 113-acre productive, nutrient-rich eutrophic lake in Warren County, Iowa. Water quality is graded F based on 2 sampling years through 2024. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available. Compared to the 1 other monitored lakes in Warren County, Lake Ahquabi ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2024-06-18. Grade methodology: LakeGrade methodology.
Watch Lake Ahquabi water quality
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Swimming Safety
Based on E. coli testing, Lake Ahquabi frequently exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 18.8% of 85 samples across 5 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.
Water Quality Grade: F, Very Poor
Very murky, less than 1.8 ft of visibility. Chlorophyll-a: 42.1 µg/L. Trophic State Index: 68.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.8 ft | F |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | 42.1 µg/L | F |
| Trophic State Index (TSI) | 68 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 113 acres |
| Public Access | Yes |
Where to stay near Lake Ahquabi
Compare lakeside cabins, hotels, and vacation rentals near Lake Ahquabi in Warren County, Iowa — 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.
Top-rated places to stay near Lake Ahquabi
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Fishing Lake Ahquabi
Water Quality Trend: ↑ Improving
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.136 m/yr | 5 |
| Chlorophyll-a | ↑ Improving | -7.28 µg/L/yr | 5 |
Water Temperature
Lake Ahquabi averages about 81°F at the surface in summer, usually warmest in Jul (about 84°F) and coldest in Apr (about 58°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 111 field readings (2010–2020) via the EPA Water Quality Portal. See the full Lake Ahquabi water temperature breakdown →
Location & Depth Map
Free interactive depth-contour map of Lake Ahquabi, reaching a maximum surveyed depth of 18 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Iowa DNR.
County Ranking
Ranked #2 of 2 lakes in Warren County
Cleaner Lakes Within 30 Miles
Lake Ahquabi holds Grade F. 3 nearby lakes hold higher grades.
- BDale Maffitt ReservoirDallas County · 18.5 mi · Two grade letters higher (F → B)
- DHooper Pond LakeWarren County · 1.1 mi · Higher grade (F → D)
- DEaster LakePolk County · 17.5 mi · Higher grade (F → D)
Nearby Lakes in Warren County
Explore Lake Ahquabi across LakeGrade
More Iowa Lake Rankings
Other Grade F Lakes in Iowa
Eutrophic Lakes in Iowa
More records, surveys & data sources
Reservoir Info (USACE NID)
Lake Ahquabi is a man-made reservoir impounded by the Lake Ahquabi Dam (completed 1935), built primarily for recreation on the TR- SQUAW CREEK; earth-type dam, 43 ft tall and 1,020 ft long.
- Surface area
- 113 ac
- Normal storage
- 1,280 ac-ft
- Max storage
- 2,395 ac-ft
- Drainage area
- 5.16 sq mi
- Hazard class
- Significant
- Owner
- Iowa Department of Natural Resources
Source: USACE National Inventory of Dams, NID ID IA01131 · Operator website
EPA Impairment Status
Lake Ahquabi 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 04-LDM-1080 · Official waterbody report
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth is a modeled estimate.
Regulated Pollution Sources Nearby
2 EPA-permitted facilities operate within about 5 miles of Lake Ahquabi under Clean Water Act (NPDES) discharge permits. 2 facilities have a reported Clean Water Act violation in the past three years.
- Wesley Woods Camp & Retreat CenterIndianola · 0.3 mi away · NPDES IA0075523Recent violation
- Dnr Lake Ahquabi State ParkIndianola · 0.3 mi away · NPDES IA0066001Recent violation
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
Data Sources
Water quality data from the EPA Water Quality Portal
Impairment status from EPA ATTAINS 303(d) database
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Grading methodology based on Metropolitan Council standards
Most recent sample: 2024-06-18
Monitoring stations: 1