Cold Springs Lake
Cass County, Iowa16 acresView mapDirections
Nutrients and algae run above the regional average.
- Eutrophic
- #1 of 2 in the county
Cold Springs Lake in Cass County, Iowa has a water quality grade of D (Nutrient-rich). Water clarity: 4.8 ft visibility. Phosphorus: 35 µg/L. Chlorophyll-a (algae): 21.6 µg/L. Surface area: 15.5 acres.
- Clarity
- 4.8 ft
- Typical in September
- 71°F
- Area
- 16 acres
- Type
- Eutrophic
- Trend
- ↓ Declining
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 grade measures 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 Sep 11–13, 4 adults. Change dates on the map below.
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Watch Cold Springs Lake’s letter
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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. Water quality is graded D based on 2 sampling years through 2024. 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. Grade methodology: LakeQuality methodology.
Swimming Safety
Grade onlyAlgae risk
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
The D is nutrients and algae, not a swimming clearance. Check local advisories before you swim.
Water Quality Grade: D (Nutrient-rich)
Murky, only visible to about 4.8 ft. Phosphorus 35 µg/L. Chlorophyll-a 21.6 µg/L. TSI 57. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4.8 ft | Not graded |
| Phosphorus | 35 µg/L | Good |
| Chlorophyll-a (Algae) | 21.6 µg/L | Poor |
| Trophic State Index (TSI) | 57 | Eutrophic |
High nutrients, frequent algae, reduced clarity
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.
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
| Characteristic | Value |
|---|---|
| Surface Area | 16 acres |
No bathymetric survey has been published for Cold Springs Lake, so its depth is not documented here.
Fishing Cold Springs Lake
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.019 m/yr | 5 |
| Phosphorus | ↓ Declining | +1.6 µg/L/yr | 4 |
| Chlorophyll-a | ↓ Declining | +3.52 µg/L/yr | 5 |
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.
County Ranking
Ranked #1 of 2 lakes in Cass County
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. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Cold Springs Lake?
- Cold Springs Lake in Cass County, Iowa has a water quality grade of D (Nutrient-rich). 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?
- The D is nutrients and algae, 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 Iowa Lake Rankings
Other Grade D 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)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Regulated discharger data from EPA ECHO (ICIS-NPDES)