Littlefield Lake
Audubon County, Iowa69 acresView mapDirections
Nutrients and algae run well above the regional average.
- Hypereutrophic
- Impaired · Algal growth
- #1 of 1 in the county
- 50 ft max depth
Littlefield Lake in Audubon County, Iowa has a water quality grade of F (Algae-prone). Water clarity: 0.9 ft visibility. Phosphorus: 225 µg/L. Chlorophyll-a (algae): 103.1 µg/L. Surface area: 69 acres.
- Clarity
- 0.9 ft
- Typical in September
- 70°F
- Max depth
- ~50 ft est.
- Area
- 69 acres
- Type
- Hypereutrophic
- Phosphorus
- 225 µg/L
- Chlorophyll-a
- 103.1 µg/L
- Trend
- ↓ Declining
Stays via Stay22
Stays near Littlefield Lake
Compare lakeside cabins, hotels, and vacation rentals near Littlefield Lake in Audubon 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 Littlefield Lake are listed below.
Top-rated places to stay near Littlefield Lake
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Watch Littlefield Lake’s letter
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Free interactive depth-contour map of Littlefield Lake, reaching a maximum surveyed depth of 14 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Iowa DNR.
Littlefield Lake is a 69-acre highly nutrient-loaded hypereutrophic lake in Audubon County, Iowa with an estimated average depth of about 50 feet. Water quality is graded F based on 2 sampling years through 2024. Overall water quality is declining over recent sampling years.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2024-09-29. 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. Littlefield 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 225 µg/L. Chlorophyll-a 103.1 µg/L. TSI 79. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 0.9 ft | Not graded |
| Phosphorus | 225 µg/L | Poor |
| Chlorophyll-a (Algae) | 103.1 µg/L | Poor |
| Trophic State Index (TSI) | 79 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Water Temperature
Littlefield Lake typically sits around 70°F at the surface in September. Summer average is about 78°F. Usually warmest in Jul (about 81°F) and coldest in Sep (about 70°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 29 field readings (2010–2023) via the EPA Water Quality Portal. See the full Littlefield Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~50 ft est. |
| Average Depth | ~12 ft est. |
| Surface Area | 69 acres |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Iowa has not published bathymetry for Littlefield 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 Littlefield Lake
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.027 m/yr | 5 |
| Phosphorus | → Stable | +1.15 µg/L/yr | 4 |
| Chlorophyll-a | ↓ Declining | +30.75 µg/L/yr | 5 |
Reservoir Info (USACE NID)
Littlefield Lake is a man-made reservoir impounded by the Littlefield Lake Dam (completed 1977), built primarily for flood risk reduction on the TR-TROUBLESOME CREEK; earth-type dam, 45 ft tall and 1,205 ft long.
- Surface area
- 69 ac
- Normal storage
- 561 ac-ft
- Max storage
- 2,278 ac-ft
- Drainage area
- 3.95 sq mi
- Hazard class
- High
- Owner
- Audubon County Conservation Board
All listed purposes: Flood Risk Reduction;Recreation.
Source: USACE National Inventory of Dams, NID ID IA01691 · Operator website
EPA Impairment Status
Littlefield 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 05-NSH-1439 · Official waterbody report
County Ranking
Ranked #1 of 1 lakes in Audubon County
Nearby Lakes With Higher Grades
Littlefield 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 Audubon County
Frequently asked questions about Littlefield Lake
Where is Littlefield Lake?
- Littlefield Lake is a lake in Audubon County, Iowa. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Littlefield Lake?
- Littlefield Lake in Audubon County, Iowa has a water quality grade of F (Algae-prone). Water clarity: 0.9 ft visibility. Phosphorus: 225 µg/L. Chlorophyll-a (algae): 103.1 µg/L. Surface area: 69 acres.
Is Littlefield Lake safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Littlefield 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 Littlefield Lake?
- Littlefield Lake typically sits around 70°F at the surface in September, from 29 EPA Water Quality Portal field readings (2010–2023). That is a typical value for the month, not a live reading.
How deep is Littlefield Lake?
- No published bathymetric survey covers Littlefield Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 50 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 69 acres.
Explore Littlefield Lake across LakeQuality
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Where this data comes from
61 measurements from 1 monitoring station, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Iowa DNR Surface Water Monitoring Data
21IOWA_WQX61 samples · 2020–2024
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)