Lake Geode
Des Moines County, Iowa195 acresView mapDirections
Iowa DNR publishes the water-quality measurements for Lake Geode. Here is what has been measured.
- Hypereutrophic
- Impaired · Mercury
- Public access
Lake Geode in Des Moines County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 2.1 ft visibility. Phosphorus: 53.5 µg/L. Chlorophyll-a (algae): 30.5 µg/L. Surface area: 195 acres.
Lake Geode is a 195-acre highly nutrient-loaded hypereutrophic lake in Des Moines County, Iowa. Phosphorus level is improving over recent sampling years. Limited fish-species data available. Public access is available. Compared to the 1 other monitored lakes in Des Moines County, Lake Geode ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2024-09-16. Methodology: how these readings are compared.
Lake Geode covers about 200 acres in Des Moines County. If you are planning to stay, you can search lake houses and cabins around Lake Geode on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
Swimming conditions
Readings onlyBacteria advisory
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. Lake Geode is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, pathogens (E. coli, fecal), pH / acidity. Check local advisories before you swim.
Whether Lake Geode 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 Lake Geode
These are the measurements Iowa DNR publishes for Lake Geode, 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 2.1 ft of visibility. Phosphorus 53.5 µg/L. Chlorophyll-a 30.5 µg/L. TSI 64.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 2.1ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 53.5µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 30.5µg/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. | 64 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Lake Geode
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Lake Geode typically sits around 73°F at the surface in September. Summer average is about 78°F. Usually warmest in Jul (about 81°F) and coldest in May (about 71°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (71°F) to its warmest (81°F).
Typical surface water temperature by month, from 23 field readings (2010–2023) via the EPA Water Quality Portal. See the full Lake Geode water temperature breakdown →
Lake Details
Surface area
195 acres
Public access
Yes
Listed by Iowa DNR
No bathymetric survey has been published for Lake Geode, so its depth is not documented here.
Stays via Stay22
Stays near Lake Geode
Compare lakeside cabins, hotels, and vacation rentals near Lake Geode in Des Moines 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 Lake Geode are listed below.
Top-rated places to stay near Lake Geode
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 Lake Geode → · more Iowa lake trips
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Fishing Lake Geode
Water Quality Trend: Stable
Based on 4 years of monitoring (2021–2024).
Water clarity
Stable4 years
Phosphorus
Improving-11.85 µg/L/yr4 years
Chlorophyll-a
Worsening+10.4 µg/L/yr4 years
Reservoir Info (USACE NID)
Lake Geode is a man-made reservoir impounded by the Geode Lake Dam (completed 1949), built primarily for recreation on the TR-SKUNK RIVER; earth-type dam, 59 ft tall and 1,060 ft long.
- Surface area
- 195 ac
- Normal storage
- 4,700 ac-ft
- Max storage
- 6,200 ac-ft
- Drainage area
- 15.35 sq mi
- Hazard class
- Significant
- Owner
- Iowa Department of Natural Resources
Source: USACE National Inventory of Dams, NID ID IA01347 · Operator website
EPA Impairment Status
Lake Geode 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: Aquatic life, Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit IA 03-SKU-896 · Official waterbody report
Regulated Pollution Sources Nearby
3 EPA-permitted facilities operate within about 5 miles of Lake Geode under Clean Water Act (NPDES) discharge permits. 2 facilities have a reported Clean Water Act violation in the past three years.
- Dnr Geode State ParkDanville · 0.8 mi away · NPDES IA0052732Recent violation
- Danville City Of StpDanville · 4.8 mi away · NPDES IA0025861Recent violation
- Dnr Geode State ParkDanville · 0.8 mi away · NPDES IA0066061
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 Des Moines County
Frequently asked questions about Lake Geode
Where is Lake Geode?
- Lake Geode is a lake in Des Moines County, Iowa. Its water-quality measurements are published by Iowa DNR and shown on this page as reported.
What is the water quality of Lake Geode?
- Lake Geode in Des Moines County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 2.1 ft visibility. Phosphorus: 53.5 µg/L. Chlorophyll-a (algae): 30.5 µg/L. Surface area: 195 acres.
Is Lake Geode safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Lake Geode is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, pathogens (E. coli, fecal), pH / acidity. Check local advisories before you swim.
What is the water temperature of Lake Geode?
- Lake Geode typically sits around 73°F at the surface in September, from 23 EPA Water Quality Portal field readings (2010–2023). That is a typical value for the month, not a live reading.
Can I fish at Lake Geode?
- Public access to Lake Geode is listed as yes on the lake record. 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 Lake Geode across LakeQuality
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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)
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)