East Okoboji Lake
Dickinson County, IowaView mapDirections
Iowa DNR publishes the water-quality measurements for East Okoboji Lake. Here is what has been measured.
- Eutrophic
- Impaired · Mercury
- Public access
East Okoboji Lake in Dickinson County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 3.9 ft visibility. Phosphorus: 56 µg/L. Chlorophyll-a (algae): 25.3 µg/L.
Free interactive depth-contour map of East Okoboji Lake, reaching a maximum surveyed depth of 20 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Iowa DNR.
East Okoboji Lake is a productive, nutrient-rich eutrophic lake in Dickinson County, Iowa. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available with 4 public boat landings. Compared to the 7 other monitored lakes in Dickinson County, East Okoboji Lake ranks #6 for water quality.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2024-09-10. Methodology: how these readings are compared.
East Okoboji Lake has 4 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 East Okoboji Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
What East Okoboji Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch4 documented ramps
Swimming conditions
Readings onlyRecreation 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. East Okoboji Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
Whether East Okoboji 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.
Water quality measurements for East Okoboji Lake
These are the measurements Iowa DNR publishes for East Okoboji Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 3.9 ft. Phosphorus 56 µg/L. Chlorophyll-a 25.3 µg/L. TSI 61.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3.9ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 56µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 25.3µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 61 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about East Okoboji Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
East Okoboji Lake typically sits around 72°F at the surface in September. Summer average is about 75°F. Usually warmest in Jul (about 80°F) and coldest in Jun (about 69°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (69°F) to its warmest (80°F).
Typical surface water temperature by month, from 27 field readings (2010–2023) via the EPA Water Quality Portal. See the full East Okoboji Lake water temperature breakdown →
Recreation & Access
- Spring Run ComplexPublic
- Hattie Elston State ParkPublic
- Martin DrivePublic
- Parks MarinaSemi-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 East Okoboji Lake
Compare lakeside cabins, hotels, and vacation rentals near East Okoboji Lake in Dickinson 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 East Okoboji Lake are listed below.
Top-rated places to stay near East Okoboji Lake
Prices for Oct 23–25, 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 East Okoboji Lake → · more Iowa lake trips
Follow East Okoboji Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing East Okoboji Lake
Water Quality Trend: Worsening
Based on 5 years of monitoring (2020–2024).
Water clarity
Worsening5 years
Phosphorus
Worsening+3.8 µg/L/yr4 years
Chlorophyll-a
Improving-3.05 µg/L/yr5 years
EPA Impairment Status
East Okoboji Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Recreation.
Source: EPA ATTAINS assessment unit IA 06-LSR-1652 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of East Okoboji Lake under Clean Water Act (NPDES) discharge permits.
- Iowa Dot Hwy 71 ConstructionOkoboji · 0.7 mi away · NPDES IA0053380
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 Dickinson County
Frequently asked questions about East Okoboji Lake
Where is East Okoboji Lake?
- East Okoboji Lake is a lake in Dickinson County, Iowa. Its water-quality measurements are published by Iowa DNR and shown on this page as reported.
What is the water quality of East Okoboji Lake?
- East Okoboji Lake in Dickinson County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 3.9 ft visibility. Phosphorus: 56 µg/L. Chlorophyll-a (algae): 25.3 µg/L.
Is East Okoboji Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. East Okoboji Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
What is the water temperature of East Okoboji Lake?
- East Okoboji Lake typically sits around 72°F at the surface in September, from 27 EPA Water Quality Portal field readings (2010–2023). That is a typical value for the month, not a live reading.
Are there boat ramps on East Okoboji Lake?
- East Okoboji Lake has 4 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Spring Run Complex, Hattie Elston State Park, Martin Drive, Parks Marina. Public access is listed as yes.
Can I fish at East Okoboji Lake?
- East Okoboji Lake has 4 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.
Explore East Okoboji Lake across LakeQuality
More lakes in Iowa
Other Lakes in Iowa
Eutrophic Lakes in Iowa
Where this data comes from
57 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_WQX57 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)
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)
Named boat-access points from the USGS National Boat Ramps inventory