Viking Lake
Montgomery County, Iowa148 acresView mapDirections
Iowa DNR publishes the water-quality measurements for Viking Lake. Here is what has been measured.
- Hypereutrophic
- Public access
Viking Lake in Montgomery County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 3.3 ft visibility. Phosphorus: 40 µg/L. Chlorophyll-a (algae): 32.7 µg/L. Surface area: 148 acres.
Free interactive depth-contour map of Viking Lake, reaching a maximum surveyed depth of 36 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Iowa DNR.
Viking Lake is a 148-acre highly nutrient-loaded hypereutrophic lake in Montgomery 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 2024-09-30. Methodology: how these readings are compared.
Viking Lake covers about 150 acres in Montgomery County. For a place on the water, look through cabin and lake-house rentals near Viking Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
Swimming conditions
Readings onlyAlgae risk
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. Check local advisories before you swim.
Whether Viking 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 Viking Lake
These are the measurements Iowa DNR publishes for Viking 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 3.3 ft of visibility. Phosphorus 40 µg/L. Chlorophyll-a 32.7 µg/L. TSI 61.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3.3ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 40µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 32.7µg/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 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Viking Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Viking Lake typically sits around 72°F at the surface in September. Summer average is about 80°F. Usually warmest in Jul (about 83°F) and coldest in May (about 70°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (70°F) to its warmest (83°F).
Typical surface water temperature by month, from 102 field readings (2010–2023) via the EPA Water Quality Portal. See the full Viking Lake water temperature breakdown →
Lake Details
Surface area
148 acres
Public access
Yes
Listed by Iowa DNR
No bathymetric survey has been published for Viking Lake, so its depth is not documented here.
Stays via Stay22
Stays near Viking Lake
Compare lakeside cabins, hotels, and vacation rentals near Viking Lake in Montgomery 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 Viking Lake are listed below.
Top-rated places to stay near Viking 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 Viking Lake → · more Iowa lake trips
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Fishing Viking Lake
Water Quality Trend: Improving
Based on 4 years of monitoring (2021–2024).
Water clarity
Improving4 years
Phosphorus
Improving-5.2 µg/L/yr4 years
Chlorophyll-a
Stable+0.17 µg/L/yr4 years
Reservoir Info (USACE NID)
Viking Lake is a man-made reservoir impounded by the Viking Lake Dam (completed 1957), built primarily for recreation on the DUNNS CREEK; earth-type dam, 69 ft tall and 1,220 ft long.
- Surface area
- 148 ac
- Normal storage
- 1,900 ac-ft
- Max storage
- 3,450 ac-ft
- Drainage area
- 3.42 sq mi
- Hazard class
- Significant
- Owner
- Iowa Department of Natural Resources
Source: USACE National Inventory of Dams, NID ID IA01366 · Operator website
Regulated Pollution Sources Nearby
3 EPA-permitted facilities operate within about 5 miles of Viking Lake under Clean Water Act (NPDES) discharge permits. 3 facilities have a reported Clean Water Act violation in the past three years.
- Dnr Viking Lake State ParkStanton · 1.1 mi away · NPDES IA0066036Recent violation
- Stanton City Of StpStanton · 4.3 mi away · NPDES IA0042978Recent violation
- Villisca City Of StpVillisca · 4.9 mi away · NPDES IA0032549Recent 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 Montgomery County
Frequently asked questions about Viking Lake
Where is Viking Lake?
- Viking Lake is a lake in Montgomery County, Iowa. Its water-quality measurements are published by Iowa DNR and shown on this page as reported.
What is the water quality of Viking Lake?
- Viking Lake in Montgomery County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 3.3 ft visibility. Phosphorus: 40 µg/L. Chlorophyll-a (algae): 32.7 µg/L. Surface area: 148 acres.
Is Viking Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Viking Lake?
- Viking Lake typically sits around 72°F at the surface in September, from 102 EPA Water Quality Portal field readings (2010–2023). That is a typical value for the month, not a live reading.
Can I fish at Viking Lake?
- Public access to Viking Lake 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 Viking Lake across LakeQuality
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Where this data comes from
53 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_WQX53 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
Regulated discharger data from EPA ECHO (ICIS-NPDES)