Five Island Lake is a productive, nutrient-rich eutrophic lake in Palo Alto County, Iowa. Water quality is graded F based on 2 sampling years through 2024. Water clarity is declining over recent sampling years. Limited fish-species data available. Public access is available with 4 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: LakeGrade methodology.
Watch Five Island Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Avoid swimming, very poor water quality, potential algae toxins
Water Quality Grade: F, Very Poor
Very murky, less than 1.6 ft of visibility. Chlorophyll-a: 53.3 µg/L. Trophic State Index: 70.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.6 ft | F |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | 53.3 µg/L | F |
| Trophic State Index (TSI) | 70 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay 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.
Top-rated places to stay near Five Island Lake
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a trip to Five Island Lake?
Get lake water-quality report cards plus the best cabin & lodging deals near Five Island Lake — straight to your inbox. No spam, unsubscribe anytime.
Planning a whole trip? See where to stay at Iowa’s top lakes →
Fishing Five Island Lake
Water Quality Trend: → Stable
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.085 m/yr | 4 |
| Chlorophyll-a | ↑ Improving | -6.14 µg/L/yr | 4 |
Recreation & Access
Water Temperature
Five Island Lake averages about 75°F at the surface in summer, 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 →
Location & Depth Map
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.
County Ranking
Ranked #3 of 3 lakes in Palo Alto County
Cleaner Lakes Within 30 Miles
Five Island Lake holds Grade F. 3 nearby lakes hold higher grades.
- DLost Island LakePalo Alto County · 12.4 mi · Higher grade (F → D)
- DStolley Pit LakeClay County · 26.7 mi · Higher grade (F → D)
- DLower Gar LakeDickinson County · 27.5 mi · Higher grade (F → D)
Nearby Lakes in Palo Alto County
Explore Five Island Lake across LakeGrade
More Iowa Lake Rankings
Other Grade F Lakes in Iowa
Eutrophic Lakes in Iowa
More records, surveys & data sources
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
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth is a modeled estimate.
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.
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
Public boat-access points from the USGS National Boat Ramps inventory
Most recent sample: 2024-09-11
Monitoring stations: 1