Rivers in Iowa

Floyd River at Merrill

Plymouth County, IowaNWS MRLI4Sioux Falls office

Below flood stage
0.38ftStage

Observed Mon, Sep 21, 8:30 PM CDT

Flood stage
12.00 ft
Record crest
20.19 ft2024

Open the live map with the river flood outlook

Flood stages and impacts

CategoryStage
Major flood16.00 ft
Moderate flood14.00 ft
Minor flood12.00 ft
Action10.00 ft
  1. 24.00 ft230th Street east of the bridge at the gage will be flooded. Water nears the feedhorn of the automated sensor and thus river level data may be lost.
  2. 23.00 ftWater reaches the bottom of the bridge at the gauging location on 230th Street.
  3. 22.00 ftPortions of Hwy 75 near Merrill begin to flood. The bridge on County Road C38 is overtopped. The highest banks and levees are overtopped.
  4. 20.50 ftThe railroad tracks at the bridge 750 feet upstream of the gage are flooded.
  5. 19.00 ftWater reaches the bottom of the bridge on County Road C38. Approximately 2200 acres of farm land are flooded.
  6. 17.50 ftThe levees protecting the sewage treatment lagoons on the left bank of the river are overtopped.
  7. 16.00 ftFlooding begins to affect the eastern edges of the city of Merrill, including some structures. The lowest portions of C44 also begin to flood. About 2000 acres of farm land are under water.
  8. 14.00 ftApproximately 1600 acres of farm land are flooded. The utility station off of C44 may flood if levee protection fails.
  9. 12.00 ftFlooding of the low lying farm land begins.
  10. 10.00 ftThe lowest banks begin to be overtopped.

Flood outlook

Chance of flooding, September to November

CategoryChance
Minor floodingUnder 5%
Moderate floodingUnder 5%
Major floodingUnder 5%

The three-month chances are the River Forecast Centers’ long-range flood outlook, issued August 26, 2026.

Crest history

51 crests on NOAA’s list since 1901.

#DateStage
1June 23, 202420.19 ft
2September 18, 192620.00 ft
3June 7, 193418.40 ft
4June 8, 195318.00 ft
5March 15, 201917.60 ft
6September 21, 201817.00 ft
7June 16, 198317.00 ft
8March 24, 197917.00 ft
9January 1, 190116.80 ft
10April 5, 196916.60 ft
11April 4, 196616.50 ft
12March 29, 196216.03 ft
13March 29, 196016.00 ft
14February 19, 197115.98 ft
15June 21, 199615.90 ft
16March 5, 193715.60 ft
17June 4, 194215.25 ft
18June 9, 193215.00 ft
19March 30, 195214.80 ft
20March 28, 191214.80 ft
21March 22, 191714.50 ft
22March 10, 193614.50 ft
23June 18, 195014.50 ft
24July 4, 195114.30 ft
25May 13, 194414.20 ft

Most recent crests

  • July 31, 2025: 8.44 ft
  • June 23, 2024: 20.19 ft
  • August 7, 2023: 3.75 ft
  • June 24, 2020: 2.19 ft
  • March 15, 2019: 17.60 ft
  • September 21, 2018: 17.00 ft
  • July 31, 2010: 12.20 ft
  • April 14, 2001: 10.00 ft
  • March 12, 1997: 8.70 ft
  • June 21, 1996: 15.90 ft

Nearby

Upstream, downstream and the gauges around this one.

What this means

Forecasts by the Missouri Basin River Forecast Center. Forecasts are issued as needed during times of high water, but are not routinely available. River forecasts for this location take into account past precipitation and the precipitation amounts expected approximately 48 hours into the future from the forecast issuance time. River forecasts for this location take into account past precipitation and the precipitation amounts expected approximately 24 hours into the future from the forecast issuance time. Gauge reading may be affected by ice.

Sources

Stage, flood stages, impacts and crest history from NOAA’s National Water Prediction Service.