Lake Pahoja
Lyon County, Iowa72 acresView mapDirections
Iowa DNR publishes the water-quality measurements for Lake Pahoja. Here is what has been measured.
- Hypereutrophic
- Impaired · Pathogens (E. coli, fecal)
- Public access
Lake Pahoja in Lyon County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 1.7 ft visibility. Phosphorus: 218 µg/L. Chlorophyll-a (algae): 44.8 µg/L. Surface area: 71.5 acres.
Free interactive depth-contour map of Lake Pahoja, reaching a maximum surveyed depth of 24 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Iowa DNR.
Lake Pahoja is a 72-acre highly nutrient-loaded hypereutrophic lake in Lyon County, Iowa. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2024-09-09. Methodology: how these readings are compared.
Lake Pahoja covers about 72 acres in Lyon County. For a place on the water, look through cabin and lake-house rentals near Lake Pahoja on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
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 Pahoja is listed impaired under Clean Water Act §303(d) (IR 5) for pathogens (E. coli, fecal). Check local advisories before you swim.
Whether Lake Pahoja 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 Pahoja
These are the measurements Iowa DNR publishes for Lake Pahoja, 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 1.7 ft of visibility. Phosphorus 218 µg/L. Chlorophyll-a 44.8 µg/L. TSI 73.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 1.7ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 218µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 44.8µg/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. | 73 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Lake Pahoja
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Lake Pahoja 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 May (about 67°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (67°F) to its warmest (80°F).
Typical surface water temperature by month, from 31 field readings (2010–2023) via the EPA Water Quality Portal. See the full Lake Pahoja water temperature breakdown →
Lake Details
Surface area
72 acres
Public access
Yes
Listed by Iowa DNR
No bathymetric survey has been published for Lake Pahoja, so its depth is not documented here.
Stays via Stay22
Stays near Lake Pahoja
Compare lakeside cabins, hotels, and vacation rentals near Lake Pahoja in Lyon 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 Pahoja are listed below.
Top-rated places to stay near Lake Pahoja
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 whole trip? See where to stay at Iowa’s top lakes →
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Fishing Lake Pahoja
Water Quality Trend: Improving
Based on 4 years of monitoring (2021–2024).
Water clarity
Improving4 years
Phosphorus
Improving-32.95 µg/L/yr4 years
Chlorophyll-a
Worsening+8.27 µg/L/yr4 years
Reservoir Info (USACE NID)
Lake Pahoja is a man-made reservoir impounded by the Lake Pahoja Dam (completed 1974), built primarily for fire protection, stock, or small fish pond on the TR-KLONDIKE CREEK; earth-type dam, 50 ft tall and 1,305 ft long.
- Surface area
- 71.5 ac
- Normal storage
- 893 ac-ft
- Max storage
- 2,283 ac-ft
- Drainage area
- 6.09 sq mi
- Hazard class
- Significant
- Owner
- Lyon County Conservation Board
All listed purposes: Fire Protection, Stock, Or Small Fish Pond;Recreation.
Source: USACE National Inventory of Dams, NID ID IA00604 · Operator website
EPA Impairment Status
Lake Pahoja 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.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit IA 06-BSR-1532 · Official waterbody report
Regulated Pollution Sources Nearby
6 EPA-permitted facilities operate within about 5 miles of Lake Pahoja under Clean Water Act (NPDES) discharge permits. 2 facilities have a reported Clean Water Act violation in the past three years.
- Larchwood 1447 LlcLarchwood · 4.3 mi away · NPDES IA0052919Recent violation
- Larchwood City Of StpLarchwood · 4.9 mi away · NPDES IA0047333Recent violation
- Damon Bahnson Combined OperationInwood · 3.9 mi away · NPDES IA0084239
- Thane Fluit FeedlotInwood · 4.3 mi away · NPDES IA0053196
- Austin FluitLarchwood · 4.6 mi away · NPDES IA0084204
- Novartis Animal Health Us, Inc. (Changed To Elanco, Changed To Avach)Larchwood · 4.7 mi away · NPDES IA0073831
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 Lyon County
Frequently asked questions about Lake Pahoja
Where is Lake Pahoja?
- Lake Pahoja is a lake in Lyon 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 Pahoja?
- Lake Pahoja in Lyon County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 1.7 ft visibility. Phosphorus: 218 µg/L. Chlorophyll-a (algae): 44.8 µg/L. Surface area: 71.5 acres.
Is Lake Pahoja safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Lake Pahoja is listed impaired under Clean Water Act §303(d) (IR 5) for pathogens (E. coli, fecal). Check local advisories before you swim.
What is the water temperature of Lake Pahoja?
- Lake Pahoja typically sits around 69°F at the surface in September, from 31 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 Pahoja?
- Public access to Lake Pahoja 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 Pahoja 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)