Five Island Lake
Palo Alto County, IowaView mapDirections
Nutrients and algae run well above the regional average.
- Hypereutrophic
- Impaired · Algal growth
- #3 of 3 in the county
- 53 ft max depth
- Public access
Five Island Lake in Palo Alto County, Iowa has a water quality grade of F (Algae-prone). Water clarity: 1.6 ft visibility. Phosphorus: 82 µg/L. Chlorophyll-a (algae): 53.3 µg/L.
- Clarity
- 1.6 ft
- Typical in September
- 69°F
- Max depth
- ~53 ft est.
- Type
- Hypereutrophic
- Phosphorus
- 82 µg/L
- Chlorophyll-a
- 53.3 µg/L
- Trend
- ↓ Declining
- Public access
- Yes
Stays via Stay22
Stays near Five Island Lake
Compare lakeside cabins, hotels, and vacation rentals near Five Island Lake in Palo Alto 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 Five Island Lake are listed below.
Top-rated places to stay near Five Island Lake
Prices for Sep 11–13, 4 adults. Change dates on the map below.
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Free interactive depth-contour map of Five Island Lake, reaching a maximum surveyed depth of 22 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Iowa DNR.
Five Island Lake is a highly nutrient-loaded hypereutrophic lake in Palo Alto County, Iowa with an estimated average depth of about 53 feet. Water quality is graded F based on 2 sampling years through 2024. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available with 3 public boat landings. Compared to the 2 other monitored lakes in Palo Alto County, Five Island Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2024-09-11. Grade methodology: LakeQuality methodology.
What Five Island Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch3 documented ramps
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. Five Island 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 1.6 ft of visibility. Phosphorus 82 µg/L. Chlorophyll-a 53.3 µg/L. TSI 69. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.6 ft | Not graded |
| Phosphorus | 82 µg/L | Poor |
| Chlorophyll-a (Algae) | 53.3 µg/L | Poor |
| Trophic State Index (TSI) | 69 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Water Temperature
Five Island Lake typically sits around 69°F at the surface in September. Summer average is about 75°F. Usually warmest in Jul (about 80°F) and coldest in Sep (about 69°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 Five Island Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~53 ft est. |
| Average Depth | ~11 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 Five Island 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.
Recreation & Access
- Five Island LakePublic
- Five Island LakePublic
- Kearney ParkSemi-private
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Five Island Lake
Water Quality Trend: ↓ Declining
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.085 m/yr | 4 |
| Phosphorus | ↓ Declining | +4.75 µg/L/yr | 4 |
| Chlorophyll-a | ↑ Improving | -6.14 µg/L/yr | 4 |
EPA Impairment Status
Five Island 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-UDM-1300 · Official waterbody report
Regulated Pollution Sources Nearby
3 EPA-permitted facilities operate within about 5 miles of Five Island Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 3 facilities have a reported Clean Water Act violation in the past three years.
- Emmetsburg City Of StpEmmetsburg · 3.5 mi away · NPDES IA0021580MajorRecent violation
- Poet Biorefining - Emmetsburg, LlcEmmetsburg · 3.1 mi away · NPDES IA0078492Recent violation
- Iowa Lakes Regional Water Osgood PlantGraettinger · 4.8 mi away · NPDES IA0081183Recent 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.
County Ranking
Ranked #3 of 3 lakes in Palo Alto County
Nearby Lakes With Higher Grades
Five Island Lake holds Grade F. 3 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Palo Alto County
Frequently asked questions about Five Island Lake
Where is Five Island Lake?
- Five Island Lake is a lake in Palo Alto County, Iowa. LakeQuality grades it F for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Five Island Lake?
- Five Island Lake in Palo Alto County, Iowa has a water quality grade of F (Algae-prone). Water clarity: 1.6 ft visibility. Phosphorus: 82 µg/L. Chlorophyll-a (algae): 53.3 µg/L.
Is Five Island Lake safe to swim in?
- The F is nutrients and algae, not a swimming clearance. Five Island 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 Five Island Lake?
- Five Island Lake typically sits around 69°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.
How deep is Five Island Lake?
- No published bathymetric survey covers Five Island Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 53 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Are there boat ramps on Five Island Lake?
- Five Island Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Five Island Lake, Five Island Lake, Kearney Park. Public access is listed as yes.
Explore Five Island Lake across LakeQuality
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Other Grade F Lakes in Iowa
Hypereutrophic Lakes in Iowa
Where this data comes from
51 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_WQX51 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)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Named boat-access points from the USGS National Boat Ramps inventory