Beaver Lake
Dallas County, Iowa34 acresView mapDirections
Iowa DNR publishes the water-quality measurements for Beaver Lake. Here is what has been measured.
- Hypereutrophic
- Impaired · Algal growth
- Public access
Beaver Lake in Dallas County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 1.9 ft visibility. Phosphorus: 105 µg/L. Chlorophyll-a (algae): 62.2 µg/L. Surface area: 34 acres.
Free interactive depth-contour map of Beaver Lake, reaching a maximum surveyed depth of 39 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Iowa DNR.
Beaver Lake is a 34-acre highly nutrient-loaded hypereutrophic lake in Dallas County, Iowa. Water clarity is improving over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 1 other monitored lakes in Dallas County, Beaver Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2024-09-30. Methodology: how these readings are compared.
Beaver Lake covers about 34 acres in Dallas County. It has one public boat landing. For a place on the water, look through cabin and lake-house rentals near Beaver Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
What Beaver Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
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. Beaver Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for algal growth, pH / acidity. Check local advisories before you swim.
Whether Beaver 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 Beaver Lake
These are the measurements Iowa DNR publishes for Beaver 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 1.9 ft of visibility. Phosphorus 105 µg/L. Chlorophyll-a 62.2 µg/L. TSI 70.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 1.9ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 105µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 62.2µg/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. | 70 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Beaver Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Beaver Lake typically sits around 71°F at the surface in September. Summer average is about 77°F. Usually warmest in Jul (about 81°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 (81°F).
Typical surface water temperature by month, from 39 field readings (2010–2023) via the EPA Water Quality Portal. See the full Beaver Lake water temperature breakdown →
Lake Details
Surface area
34 acres
Public access
Yes
Listed by Iowa DNR
No bathymetric survey has been published for Beaver Lake, so its depth is not documented here.
Recreation & Access
- Beaver Lake Wildlife AreaPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Beaver Lake
Compare lakeside cabins, hotels, and vacation rentals near Beaver Lake in Dallas 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 Beaver Lake are listed below.
Top-rated places to stay near Beaver 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 whole trip? See where to stay at Iowa’s top lakes →
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Fishing Beaver Lake
Water Quality Trend: Stable
Based on 5 years of monitoring (2020–2024).
Water clarity
Improving5 years
Phosphorus
Worsening+82.8 µg/L/yr4 years
Chlorophyll-a
Stable-0.63 µg/L/yr5 years
Reservoir Info (USACE NID)
Beaver Lake is a man-made reservoir impounded by the Beaver Lake Dam (completed 1990), built primarily for recreation on the TR-BEAR CREEK; earth-type dam, 43 ft tall and 666 ft long.
- Surface area
- 34 ac
- Normal storage
- 319 ac-ft
- Max storage
- 696 ac-ft
- Drainage area
- 1.61 sq mi
- Hazard class
- Significant
- Owner
- Iowa Department of Natural Resources
Source: USACE National Inventory of Dams, NID ID IA02498 · Operator website
EPA Impairment Status
Beaver Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
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 04-RAC-1182 · Official waterbody report
Regulated Pollution Sources Nearby
3 EPA-permitted facilities operate within about 5 miles of Beaver Lake under Clean Water Act (NPDES) discharge permits. 3 facilities have a reported Clean Water Act violation in the past three years.
- Dexter City Of StpDexter · 1.9 mi away · NPDES IA0058661Recent violation
- Redfield City Of StpRedfield · 3.3 mi away · NPDES IA0036099Recent violation
- Diamondhead LakeDexter · 3.4 mi away · NPDES IA0068381Recent 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 Dallas County
Frequently asked questions about Beaver Lake
Where is Beaver Lake?
- Beaver Lake is a lake in Dallas County, Iowa. Its water-quality measurements are published by Iowa DNR and shown on this page as reported.
What is the water quality of Beaver Lake?
- Beaver Lake in Dallas County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 1.9 ft visibility. Phosphorus: 105 µg/L. Chlorophyll-a (algae): 62.2 µg/L. Surface area: 34 acres.
Is Beaver Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Beaver Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for algal growth, pH / acidity. Check local advisories before you swim.
What is the water temperature of Beaver Lake?
- Beaver Lake typically sits around 71°F at the surface in September, from 39 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 Beaver Lake?
- Beaver Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Beaver Lake Wildlife Area. Public access is listed as yes.
Can I fish at Beaver Lake?
- Beaver Lake has 1 documented boat landing 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 Beaver Lake across LakeQuality
More lakes in Iowa
Other Lakes in Iowa
Hypereutrophic Lakes in Iowa
Where this data comes from
62 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_WQX62 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