Ottumwa Lagoon Max Depth Lake
Wapello County, IowaView mapDirections
Nutrients and algae run well above the regional average.
- Hypereutrophic
- Impaired · Algal growth
- #1 of 1 in the county
- 31 ft max depth
- Public access
Ottumwa Lagoon Max Depth Lake in Wapello County, Iowa has a water quality grade of F (Algae-prone). Water clarity: 0.9 ft visibility. Phosphorus: 261 µg/L. Chlorophyll-a (algae): 86.9 µg/L.
- Clarity
- 0.9 ft
- Typical in September
- 77°F
- Max depth
- ~31 ft est.
- Type
- Hypereutrophic
- Phosphorus
- 261 µg/L
- Chlorophyll-a
- 86.9 µg/L
- Trend
- ↑ Improving
- Public access
- Yes
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Stays near Ottumwa Lagoon Max Depth Lake
Compare lakeside cabins, hotels, and vacation rentals near Ottumwa Lagoon Max Depth Lake in Wapello 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Ottumwa Lagoon Max Depth Lake are listed below.
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Free interactive depth-contour map of Ottumwa Lagoon Max Depth Lake, reaching a maximum surveyed depth of 13 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Iowa DNR.
Ottumwa Lagoon Max Depth Lake is a highly nutrient-loaded hypereutrophic lake in Wapello County, Iowa with an estimated average depth of about 31 feet. 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.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2024-09-16. Grade methodology: LakeQuality methodology.
Swimming Safety
Grade onlyAlgae risk
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. Ottumwa Lagoon Max Depth Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for algal growth, turbidity. Check local advisories before you swim.
Water Quality Grade: F (Algae-prone)
Very murky, less than 0.9 ft of visibility. Phosphorus 261 µg/L. Chlorophyll-a 86.9 µg/L. TSI 79. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 0.9 ft | Not graded |
| Phosphorus | 261 µg/L | Poor |
| Chlorophyll-a (Algae) | 86.9 µg/L | Poor |
| Trophic State Index (TSI) | 79 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Water Temperature
Ottumwa Lagoon Max Depth Lake typically sits around 77°F at the surface in September. Summer average is about 81°F. Usually warmest in Jul (about 84°F) and coldest in Sep (about 77°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 11 field readings (2017–2023) via the EPA Water Quality Portal. See the full Ottumwa Lagoon Max Depth Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~31 ft est. |
| Average Depth | ~8 ft est. |
| Public Access | Yes |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Iowa has not published bathymetry for Ottumwa Lagoon Max Depth 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.
Fishing Ottumwa Lagoon Max Depth Lake
Water Quality Trend: ↑ Improving
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.016 m/yr | 4 |
| Phosphorus | ↑ Improving | -14.25 µg/L/yr | 4 |
| Chlorophyll-a | ↑ Improving | -8.16 µg/L/yr | 4 |
EPA Impairment Status
Ottumwa Lagoon Max Depth 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 IA 04-LDM-1014 · Official waterbody report · Matched by proximity (0.64 km)
County Ranking
Ranked #1 of 1 lakes in Wapello County
Nearby Lakes With Higher Grades
Ottumwa Lagoon Max Depth Lake 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.
See full comparison →Nearby Lakes in Wapello County
Frequently asked questions about Ottumwa Lagoon Max Depth Lake
Where is Ottumwa Lagoon Max Depth Lake?
- Ottumwa Lagoon Max Depth Lake is a lake in Wapello County, Iowa. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Ottumwa Lagoon Max Depth Lake?
- Ottumwa Lagoon Max Depth Lake in Wapello County, Iowa has a water quality grade of F (Algae-prone). Water clarity: 0.9 ft visibility. Phosphorus: 261 µg/L. Chlorophyll-a (algae): 86.9 µg/L.
Is Ottumwa Lagoon Max Depth Lake safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Ottumwa Lagoon Max Depth Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for algal growth, turbidity. Check local advisories before you swim.
What is the water temperature of Ottumwa Lagoon Max Depth Lake?
- Ottumwa Lagoon Max Depth Lake typically sits around 77°F at the surface in September, from 11 EPA Water Quality Portal field readings (2017–2023). That is a typical value for the month, not a live reading.
How deep is Ottumwa Lagoon Max Depth Lake?
- No published bathymetric survey covers Ottumwa Lagoon Max Depth Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 31 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Explore Ottumwa Lagoon Max Depth Lake across LakeQuality
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Where this data comes from
48 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_WQX48 samples · 2021–2024
Analytical methods
- Unknown
- Phosphorus by Colorimetry
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- In-Vitro Determination of Chlorophyll
- ISU modification of APHA 2130-B
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)