Iowa River At Marshalltown Flow Report
As of August 3, 2026, Iowa River At Marshalltown is flowing at 661 cfs with a gage height of 10.73 ft, rising 15% over the past 24 hours. Source: USGS gauge #05451500, refreshed throughout the day.
Historical Data
Iowa River At Marshalltown at a glance
How Iowa River At Marshalltown is running right now, where it sits on the map, and the key gauge stats.
Iowa River At Marshalltown is flowing at 661 cfs, with the water sitting 10.73 ft at the gage. Flow is up 15% since yesterday — a rising hydrograph.
This is USGS gauge #05451500 in Iowa. Over the past 10 days the average has been 600 cfs, peaking at 779 cfs.
For real-time updates and historical context, see the realtime view or the historical comparison. Browse other gauges in the Iowa flow report.
Engineering Data
Flow-duration statistics and observed peak-flow context computed from this gauge’s complete daily record (USGS #05451500).
Estimate flows at an ungauged site
Drainage-area ratio transfer from this gauge . Most reliable for hydrologically similar sites in the same watershed with area ratios between roughly 0.5 and 1.5.
Percentiles are flow-duration values computed from this gauge’s observed daily record as archived by Snoflo. Return periods are Weibull plotting-position estimates from observed annual maxima, provided as general reference context only. Always verify against official USGS NWIS records. Part of Snoflo for Engineering.
Streamflow Forecast
Over the next 5 days, Iowa River At Marshalltown is expected to hold near today's 661 cfs, toward roughly 611 cfs by 2026-08-07 (likely range 205-1827 cfs) -- drier than normal for the date.
Powered by PULSE — Snoflo’s forecast engine, trained on this gauge’s full record of storms, snowmelt, and dry spells.
| Date | Expected (p50) | Likely range (p25–p75) | vs normal | Projected stage |
|---|
How does this compare to past years?
Year-over-year overlay, annual peak discharge, the full distribution of daily flows on record, and the gauge's rating curve.
Weather Forecast
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day forecast
Daily temperatures, snow, and rain projected over the next two weeks.
Iowa River At Marshalltown
The constituents of the river are typical for Midwestern streams, including sediment, nutrients, and some pollutants. The river has several tributaries upstream, including the English and South Skunk Rivers, as well as several small dams along its course. During the summer months, flow is typically low but can be impacted by localized storms. In the winter, flow can be high due to snow melt. Interesting facts about the hydrology of the Iowa River include its history of flooding and the construction of levees and floodwalls to mitigate flood damage.
Nearby streamflow levels
Cross-check Iowa River At Marshalltown's discharge against nearby gauges to spot whether the change here is local or regional.
| Gauge | Streamflow |
|---|---|
| Iowa River At Marshalltown | 661 cfs |
| Timber Creek Near Marshalltown | 75 cfs |
| South Fork Iowa River Ne Of New Providence | 50 cfs |
| Richland Creek Near Haven | 16 cfs |
| Indian Creek Near Mingo | 191 cfs |
| Walnut Creek Near Hartwick | 18 cfs |
Nearby snowpack data
Snowpack at SNOTEL stations near Iowa River At Marshalltown. Spring snowmelt is the dominant driver of streamflow in mountain basins -- a deep snowpack upstream means more runoff later in the season.
| SNOTEL station | Snowpack |
|---|---|
| Grundy Center | 0 in |
| Eldora | 0 in |
| Blo Squaw Ck On The South Skunk R. | 0 in |
| Belle Plaine | 0 in |
| Ames 0.9 Ene | 0 in |
| Ames 2.1 N | 0 in |
Plan a trip
Reservoirs, boat launches, river runs, and fishing spots within driving distance of Iowa River At Marshalltown.
River levels & flood safety
- Read the level before you go
- A river that's runnable at one flow can be deadly at another. Check current discharge and gage height — like the values shown above — against the flood-stage thresholds, and remember levels can spike fast after rain or a dam release.
- Respect cold water
- Snowmelt rivers run cold even in summer. Sudden immersion triggers cold-water shock and saps strength within minutes. Wear a PFD, dress for the water temperature (not the air), and never wade or paddle alone.
- Watch for swiftwater hazards
- Strainers (downed trees), undercut rocks, and low-head dams are the deadliest features on moving water. High, fast, muddy water hides them. If in doubt, scout from shore and portage.
- Mind flash floods & releases
- Narrow canyons can flood from a storm miles upstream, and dam-controlled reaches can rise without warning. Know the forecast, the release schedule, and your exit before you launch.
Track Iowa River At Marshalltown in the Snoflo app
Save this gauge as a favorite, set push alerts when streamflow crosses a threshold (e.g. "alert me when Iowa River At Marshalltown crosses 5,000 cfs"), and Snoflo's iOS app will push the moment USGS reports the crossing.
About Iowa River At Marshalltown
What is the Iowa River At Marshalltown flow rate right now?
As of August 3, 2026, Iowa River At Marshalltown is flowing at 661 cfs. The live value, gage height, and 24-hour trend are shown at the top of this page.
Is the Iowa River At Marshalltown running high or low right now?
Check the percent of median figure on this page: above 100% means Iowa River At Marshalltown is running higher than normal for the date, below 100% means lower. The 24-hour trend shows whether it's rising or falling.
Where does the streamflow data for Iowa River At Marshalltown come from?
Discharge, gage height, and water temperature come directly from the USGS streamflow gauge 05451500. Snoflo refreshes the time series throughout the day. Forecasts come from the NOAA / yr.no feed Snoflo's iOS app uses.
How often is the report updated?
USGS gauges report continuously (typically every 15 minutes). Snoflo pulls fresh values throughout the day — look for the "as of" timestamp on the streamflow hero card.
What's the difference between discharge and gage height?
Discharge (cubic feet per second, or cfs) is the volume of water flowing past the gauge each second. Gage height is how high the water sits at the gauge (feet). They're related by a rating curve specific to each gauge — higher water means more flow, but the exact ratio depends on channel shape.
How is "percent of median" calculated?
Today's discharge is compared to the historical median discharge on this calendar day across the gauge's full record. 100% = right on median; 200% = a very high year; 30% = a drought-level low.
What are flood stages, and is this river safe right now?
Flood stages are NWS-defined gage-height thresholds — Action, Minor, Moderate, Major — marking when nearby roads or floodplains start to be affected. "Safe" depends on your activity and skill: a level that's a fun paddle for an expert can be lethal for a wader. Always check the current level against the thresholds above and the safety links, and when in doubt, stay off the water.
Can I get alerts when Iowa River At Marshalltown rises?
Yes — flow alerts are managed in the Snoflo iOS app. Favorite this gauge, set a streamflow threshold (e.g. "alert me when discharge crosses 5,000 cfs"), and you'll get a push the moment USGS reports the crossing.
Access the free Iowa River At Marshalltown report
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