Cold Springs Lake
Cass County, Iowa16 acresView mapDirections
Iowa DNR publishes the water-quality measurements for Cold Springs Lake. Here is what has been measured.
- Eutrophic
Cold Springs Lake in Cass County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 4.8 ft visibility. Phosphorus: 35 µg/L. Chlorophyll-a (algae): 21.6 µg/L. Surface area: 15.5 acres.
Free interactive depth-contour map of Cold Springs Lake, reaching a maximum surveyed depth of 14 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Iowa DNR.
Cold Springs Lake is a 16-acre productive, nutrient-rich eutrophic lake in Cass County, Iowa. Overall water quality is declining over recent sampling years. Compared to the 1 other monitored lakes in Cass County, Cold Springs Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2024-09-29. Methodology: how these readings are compared.
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 Cold Springs 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 Cold Springs Lake
These are the measurements Iowa DNR publishes for Cold Springs 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 4.8 ft. Phosphorus 35 µg/L. Chlorophyll-a 21.6 µg/L. TSI 57.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 4.8ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 35µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 21.6µg/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. | 57 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Cold Springs Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Cold Springs Lake typically sits around 71°F at the surface in September. Summer average is about 80°F. Usually warmest in Jul (about 83°F) and coldest in Sep (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 (83°F).
Typical surface water temperature by month, from 29 field readings (2010–2023) via the EPA Water Quality Portal. See the full Cold Springs Lake water temperature breakdown →
Lake Details
Surface area
16 acres
No bathymetric survey has been published for Cold Springs Lake, so its depth is not documented here.
Stays via Stay22
Stays near Cold Springs Lake
Compare lakeside cabins, hotels, and vacation rentals near Cold Springs Lake in Cass 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 Cold Springs Lake are listed below.
Top-rated places to stay near Cold Springs 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 →
Follow Cold Springs Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing Cold Springs Lake
Water Quality Trend: Worsening
Based on 5 years of monitoring (2020–2024).
Water clarity
Stable5 years
Phosphorus
Worsening+1.6 µg/L/yr4 years
Chlorophyll-a
Worsening+3.52 µg/L/yr5 years
Reservoir Info (USACE NID)
Cold Springs Lake is a man-made reservoir impounded by the Cold Springs Dam (completed 1949), built primarily for recreation on the TR- EAST NISHNABOTNA RIVER; earth-type dam, 12 ft tall and 1,350 ft long.
- Surface area
- 15.5 ac
- Normal storage
- 50 ac-ft
- Max storage
- 75 ac-ft
- Drainage area
- 3.6 sq mi
- Hazard class
- Low
- Owner
- Iowa Department of Natural Resources
Source: USACE National Inventory of Dams, NID ID IA03165 · Operator website
Regulated Pollution Sources Nearby
2 EPA-permitted facilities operate within about 5 miles of Cold Springs Lake under Clean Water Act (NPDES) discharge permits.
- Lewis City Of StpLewis · 1.6 mi away · NPDES IA0057487
- J. W. Freund Farms, Inc.Lewis · 1.8 mi away · NPDES IA0078476
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 Cass County
Frequently asked questions about Cold Springs Lake
Where is Cold Springs Lake?
- Cold Springs Lake is a lake in Cass County, Iowa. Its water-quality measurements are published by Iowa DNR and shown on this page as reported.
What is the water quality of Cold Springs Lake?
- Cold Springs Lake in Cass County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 4.8 ft visibility. Phosphorus: 35 µg/L. Chlorophyll-a (algae): 21.6 µg/L. Surface area: 15.5 acres.
Is Cold Springs 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 Cold Springs Lake?
- Cold Springs Lake typically sits around 71°F at the surface in September, from 29 EPA Water Quality Portal field readings (2010–2023). That is a typical value for the month, not a live reading.
Explore Cold Springs Lake across LakeQuality
More lakes in Iowa
Other Lakes in Iowa
Eutrophic Lakes in Iowa
Where this data comes from
60 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_WQX60 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
Regulated discharger data from EPA ECHO (ICIS-NPDES)