Railroad Lake
Scott County, Iowa29 acresView mapDirections
Iowa DNR publishes the water-quality measurements for Railroad Lake. Here is what has been measured.
- Eutrophic
Railroad Lake in Scott County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 5.1 ft visibility. Phosphorus: 44.5 µg/L. Chlorophyll-a (algae): 8.3 µg/L. Surface area: 29 acres.
Free interactive depth-contour map of Railroad Lake, reaching a maximum surveyed depth of 14 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Iowa DNR.
Railroad Lake is a 29-acre productive, nutrient-rich eutrophic lake in Scott County, Iowa. Overall water quality is improving over recent sampling years. Compared to the 4 other monitored lakes in Scott County, Railroad Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2024-09-10. Methodology: how these readings are compared.
Swimming conditions
Readings onlyModerate algae
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 Railroad 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 Railroad Lake
These are the measurements Iowa DNR publishes for Railroad 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 5.1 ft. Phosphorus 44.5 µg/L. Chlorophyll-a 8.3 µg/L. TSI 55.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 5.1ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 44.5µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 8.3µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 55 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Railroad Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
29 acres
No bathymetric survey has been published for Railroad Lake, so its depth is not documented here.
Stays via Stay22
Stays near Railroad Lake
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Fishing Railroad Lake
Water Quality Trend: Improving
Based on 4 years of monitoring (2020–2024).
Water clarity
Improving4 years
Phosphorus
Improving-41.11 µg/L/yr4 years
Chlorophyll-a
Improving-51.81 µg/L/yr4 years
Reservoir Info (USACE NID)
Railroad Lake is a man-made reservoir impounded by the Railroad Lake Dam (completed 1983), built primarily for recreation on the TR- BLACK HAWK CR.; earth-type dam, 35 ft tall and 525 ft long.
- Surface area
- 29 ac
- Normal storage
- 360 ac-ft
- Max storage
- 750 ac-ft
- Drainage area
- 1.11 sq mi
- Hazard class
- Significant
- Owner
- Scott County Conservation Board
Source: USACE National Inventory of Dams, NID ID IA02208 · Operator website
Nearby Lakes in Scott County
Frequently asked questions about Railroad Lake
Where is Railroad Lake?
- Railroad Lake is a lake in Scott County, Iowa. Its water-quality measurements are published by Iowa DNR and shown on this page as reported.
What is the water quality of Railroad Lake?
- Railroad Lake in Scott County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 5.1 ft visibility. Phosphorus: 44.5 µg/L. Chlorophyll-a (algae): 8.3 µg/L. Surface area: 29 acres.
Is Railroad Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Explore Railroad Lake across LakeQuality
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Eutrophic Lakes in Iowa
Where this data comes from
40 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_WQX40 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.