Railroad Lake
Scott County, Iowa29 acresView mapDirections
Nutrients and algae sit mid-range for this region.
- Eutrophic
- Impaired · Algal growth
- #1 of 5 in the county
Railroad Lake in Scott County, Iowa has a water quality grade of C (Fair). Water clarity: 5.1 ft visibility. Phosphorus: 44.5 µg/L. Chlorophyll-a (algae): 8.3 µg/L. Surface area: 29 acres.
- Clarity
- 5.1 ft
- Area
- 29 acres
- Type
- Eutrophic
- Trend
- ↑ Improving
Stays via Stay22
Stays near Railroad Lake
Compare lakeside cabins, hotels, and vacation rentals near Railroad Lake in Scott 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.
Top-rated places to stay near Railroad Lake
Prices for Sep 11–13, 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 →
Watch Railroad Lake’s letter
Email me if this lake’s grade moves. Grades stay free.
Or email
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. Water quality is graded C based on 2 sampling years through 2024. 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. Grade methodology: LakeQuality methodology.
Swimming Safety
Grade onlyModerate
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 C is nutrients and algae, not a swimming clearance. Railroad Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for algal growth. Check local advisories before you swim.
Water Quality Grade: C (Fair)
Murky, only visible to about 5.1 ft. Phosphorus 44.5 µg/L. Chlorophyll-a 8.3 µg/L. TSI 55. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 5.1 ft | Not graded |
| Phosphorus | 44.5 µg/L | Fair |
| Chlorophyll-a (Algae) | 8.3 µg/L | Good |
| Trophic State Index (TSI) | 55 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 29 acres |
No bathymetric survey has been published for Railroad Lake, so its depth is not documented here.
Fishing Railroad Lake
Water Quality Trend: ↑ Improving
Based on 4 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.415 m/yr | 4 |
| Phosphorus | ↑ Improving | -41.11 µg/L/yr | 4 |
| Chlorophyll-a | ↑ Improving | -51.81 µg/L/yr | 4 |
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
EPA Impairment Status
Railroad Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit IA 01-NEM-68 · Official waterbody report · Matched by proximity (0.54 km)
County Ranking
Ranked #1 of 5 lakes in Scott County
Nearby Lakes in Scott County
Frequently asked questions about Railroad Lake
Where is Railroad Lake?
- Railroad Lake is a lake in Scott County, Iowa. LakeQuality grades it C for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Railroad Lake?
- Railroad Lake in Scott County, Iowa has a water quality grade of C (Fair). 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?
- The C is nutrients and algae, not a swimming clearance. Railroad Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for algal growth. Check local advisories before you swim.
Explore Railroad Lake across LakeQuality
More Iowa Lake Rankings
Other Grade C Lakes in Iowa
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)
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
Impairment status from EPA ATTAINS 303(d) database