Arrowhead Lake
Pottawattamie County, Iowa16 acresView mapDirections
Nutrients and algae run well above the regional average.
- Hypereutrophic
- Impaired · Algal growth
- #1 of 2 in the county
Arrowhead Lake in Pottawattamie County, Iowa has a water quality grade of F (Algae-prone). Water clarity: 1.8 ft visibility. Phosphorus: 136 µg/L. Chlorophyll-a (algae): 53.6 µg/L. Surface area: 15.7 acres.
- Clarity
- 1.8 ft
- Typical in September
- 70°F
- Area
- 16 acres
- Type
- Hypereutrophic
- Trend
- ↑ Improving
Stays via Stay22
Stays near Arrowhead Lake
Compare lakeside cabins, hotels, and vacation rentals near Arrowhead Lake in Pottawattamie 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 Arrowhead Lake are listed below.
Top-rated places to stay near Arrowhead Lake
Prices for Sep 11–13, 4 adults. Change dates on the map below.
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Watch Arrowhead Lake’s letter
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Free interactive depth-contour map of Arrowhead Lake, reaching a maximum surveyed depth of 12 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Iowa DNR.
Arrowhead Lake is a 16-acre highly nutrient-loaded hypereutrophic lake in Pottawattamie County, Iowa. Water quality is graded F based on 2 sampling years through 2024. Overall water quality is improving over recent sampling years. Compared to the 1 other monitored lakes in Pottawattamie County, Arrowhead Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2024-09-30. 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. Arrowhead 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 1.8 ft of visibility. Phosphorus 136 µg/L. Chlorophyll-a 53.6 µg/L. TSI 71. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.8 ft | Not graded |
| Phosphorus | 136 µg/L | Poor |
| Chlorophyll-a (Algae) | 53.6 µg/L | Poor |
| Trophic State Index (TSI) | 71 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Water Temperature
Arrowhead Lake typically sits around 70°F at the surface in September. Summer average is about 79°F. Usually warmest in Jul (about 83°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 26 field readings (2010–2023) via the EPA Water Quality Portal. See the full Arrowhead Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 16 acres |
No bathymetric survey has been published for Arrowhead Lake, so its depth is not documented here.
Fishing Arrowhead Lake
Water Quality Trend: ↑ Improving
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.128 m/yr | 4 |
| Phosphorus | → Stable | +2.3 µg/L/yr | 4 |
| Chlorophyll-a | ↑ Improving | -3.2 µg/L/yr | 4 |
Reservoir Info (USACE NID)
Arrowhead Lake is a man-made reservoir impounded by the Arrowhead Lake Dam (completed 1959), built primarily for fire protection, stock, or small fish pond on the TR-MOSQUITO CREEK; earth-type dam, 47 ft tall and 615 ft long.
- Surface area
- 15.7 ac
- Normal storage
- 139 ac-ft
- Max storage
- 348 ac-ft
- Drainage area
- 1.63 sq mi
- Hazard class
- Low
- Owner
- Pottawattamie County Conservation Board
Source: USACE National Inventory of Dams, NID ID IA00955 · Operator website
EPA Impairment Status
Arrowhead 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 06-WED-1702 · Official waterbody report
Regulated Pollution Sources Nearby
6 EPA-permitted facilities operate within about 5 miles of Arrowhead Lake under Clean Water Act (NPDES) discharge permits. 3 facilities have a reported Clean Water Act violation in the past three years.
- Neola City Of StpNeola · 1.5 mi away · NPDES IA0021041Recent violation
- Minden City Of StpMinden · 3.4 mi away · NPDES IA0048330Recent violation
- Iowa Dot Rest Area #29 & #30 I80 UnderwoodUnderwood · 4.2 mi away · NPDES IA0068918Recent violation
- Feedlot Service Co.Neola · 2.8 mi away · NPDES IA0053350
- North Ridge FeedlotNeola · 3.2 mi away · NPDES IA0077666
- Tri-Center Community SchoolNeola · 4.6 mi away · NPDES IA0067148
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.
County Ranking
Ranked #1 of 2 lakes in Pottawattamie County
Nearby Lakes in Pottawattamie County
Frequently asked questions about Arrowhead Lake
Where is Arrowhead Lake?
- Arrowhead Lake is a lake in Pottawattamie County, Iowa. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Arrowhead Lake?
- Arrowhead Lake in Pottawattamie County, Iowa has a water quality grade of F (Algae-prone). Water clarity: 1.8 ft visibility. Phosphorus: 136 µg/L. Chlorophyll-a (algae): 53.6 µg/L. Surface area: 15.7 acres.
Is Arrowhead Lake safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Arrowhead 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 Arrowhead Lake?
- Arrowhead Lake typically sits around 70°F at the surface in September, from 26 EPA Water Quality Portal field readings (2010–2023). That is a typical value for the month, not a live reading.
Explore Arrowhead Lake across LakeQuality
More Iowa Lake Rankings
Other Grade F Lakes in Iowa
Hypereutrophic Lakes in Iowa
Where this data comes from
52 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_WQX52 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
Regulated discharger data from EPA ECHO (ICIS-NPDES)