Skip to main content
LakeQuality

Five Island Lake

Palo Alto County, IowaView mapDirections

Iowa DNR publishes the water-quality measurements for Five Island Lake. Here is what has been measured.

Clarity
1.6 ft
Typical for Iowa
Secchi · sampled 2024
Phosphorus
82 µg/L
Typical for Iowa
Measured by Iowa DNR
Chlorophyll-a
53.3 µg/L
Typical for Iowa
Measured by Iowa DNR
Water temp
~69°F
Typical for Sep · EPA WQP
Max depth
~53 ft est.
GLOBathy model
Type
Hypereutrophic
Trophic class
  • Hypereutrophic
  • Impaired · Algal growth
  • 53 ft max depth
  • Public access

Five Island Lake in Palo Alto County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 1.6 ft visibility. Phosphorus: 82 µg/L. Chlorophyll-a (algae): 53.3 µg/L.

Loading 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.

Five Island Lake is a highly nutrient-loaded hypereutrophic lake in Palo Alto County, Iowa with an estimated average depth of about 53 feet. 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. Methodology: how these readings are compared.

Five Island Lake has 3 public boat landings, so a lakefront rental is not the only way to get a boat on the water. For a place on the water, look through cabin and lake-house rentals near Five Island Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.

What Five Island Lake is good for

From access and monitoring records, not editorial picks.

  • Boat launch3 documented ramps

Swimming conditions

Readings only

Recreation use not supported

Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.

Nutrient and algae readings are 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.

Whether Five Island Lake is safe to swim in today is a call for the Iowa Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

Compare swimming lakes near Mankato →

Get alerts for Five Island Lake →

Water quality measurements for Five Island Lake

These are the measurements Iowa DNR publishes for Five Island Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.

Very murky, less than 1.6 ft of visibility. Phosphorus 82 µg/L. Chlorophyll-a 53.3 µg/L. TSI 69.

Water quality readings
MeasureReadingWhere it sits
Water clarity (Secchi depth)1.6ftMeasured, not scored

How deep a black-and-white disk stays visible from the surface. Higher is clearer.

Total phosphorus82µg/LPoor
GoodFairPoor
Chlorophyll-a (algae)53.3µg/LPoor
GoodFairPoor
Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a.69Hypereutrophic
OligotrophicMesotrophicEutrophicHypereutrophic

Very high nutrients, dense algae, poor clarity

Ask about Five Island Lake

Answers come straight from the public measurements and survey records on this page.

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.

Jan
Feb
Mar
Apr
71°
May
71°
Jun
80°
Jul
73°
Aug
69°
Sep
Oct
Nov
Dec

Column height runs from this lake’s coldest month (69°F) to its warmest (80°F).

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

Max depth

~53 ft est.

Public access

Yes

Listed by Iowa DNR

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

Watershed (drainage) area

17 sq mi

HydroLAKES / HydroSHEDS

Surface area

914 acres

HydroLAKES / HydroSHEDS

Shoreline

13.7 mi

HydroLAKES / HydroSHEDS

Elevation

1,207 ft

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

3
Boat Landings
Yes
Public 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

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 readings cover 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 Oct 30–Nov 1, 4 adults. Change dates on the map below.

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? Cabins and lodging at Five Island Lake → · more Iowa lake trips

Follow Five Island Lake’s readings

Email me when new measurements post for this lake. Updates stay free.


Or email

Fishing Five Island Lake

Based on 4 years of monitoring (2021–2024).

  • Water clarity

    Worsening

    4 years

  • Phosphorus

    Worsening

    +4.75 µg/L/yr4 years

  • Chlorophyll-a

    Improving

    -6.14 µg/L/yr4 years

See year-by-year chart →

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

Algal growthTurbidity

Designated uses not supporting: Recreation.

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 Stp
    Emmetsburg · 3.5 mi away · NPDES IA0021580
    MajorRecent violation
  • Poet Biorefining - Emmetsburg, Llc
    Emmetsburg · 3.1 mi away · NPDES IA0078492
    Recent violation
  • Iowa Lakes Regional Water Osgood Plant
    Graettinger · 4.8 mi away · NPDES IA0081183
    Recent 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.

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. Its water-quality measurements are published by Iowa DNR and shown on this page as reported.

What is the water quality of Five Island Lake?

Five Island Lake in Palo Alto County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 1.6 ft visibility. Phosphorus: 82 µg/L. Chlorophyll-a (algae): 53.3 µg/L.

Measurements on this page ↑

Is Five Island Lake safe to swim in?

Nutrient and algae readings are 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.

Swimming on this page ↑

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.

Temp on this page ↑

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.

Access on this page ↑

Can I fish at Five Island Lake?

Five Island Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Iowa's fish and wildlife agency, so check its current regulations before you go.

Access on this page ↑

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 Data21IOWA_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)

EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from 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