Mississippi River Lock And Dam 9 dam
Mississippi River Lock And Dam 9
Mississippi River Lock and Dam 9, also known as Lock & Dam 9 (Winthrop Rockfeller), is a concrete run-of-river dam located in Prairie du Chien, Wisconsin. Completed in 1937, this federal-owned structure primarily serves for navigation purposes along the Mississippi River. With a dam height of 18 feet and a hydraulic height of 32 feet, it maintains a constant pool level for river traffic at elevation 619.3, with a maximum discharge capacity of 278,000 cubic feet per second.
Despite being classified as a low-risk dam by the US Army Corps of Engineers (USACE), Lock & Dam 9 faces potential hazards related to the aging miter gates in the locks and the risk of navigation accidents. USACE actively manages these risks through continuous monitoring, prioritizing maintenance activities, and engaging with the public to raise awareness of the dam's presence and potential dangers. The dam's spillway is regulated to control pool levels and can handle flows up to 63,000 cfs, with a maximum water level differential of 9 feet at low river flows. With a risk assessment rating of Very High (1), USACE remains vigilant in ensuring the safety and functionality of Lock & Dam 9 for both navigation and public safety.
Plan around the weather
Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.
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. Each cell is colour-coded relative to the column min/max.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Mississippi River Lock And Dam 9 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Yellow River At Ion | 162 cfs | → |
| Kickapoo River At Steuben | 553 cfs | → |
| Bloody Run Creek Near Marquette | 34 cfs | → |
| Mississippi River At Mcgregor | 21,700 cfs | → |
| Upper Iowa River Near Dorchester | 674 cfs | → |
| Turkey River Above French Hollow Cr At Elkader | 720 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Mississippi River Lock And Dam 9.
Boat launches
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Campgrounds
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Fishing spots
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River runs
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About Mississippi River Lock And Dam 9
Where does the data for Mississippi River Lock And Dam 9 come from?
Structural and regulatory data come from the U.S. Army Corps of Engineers' National Inventory of Dams (NID). Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
NID structural data refreshes annually as the Corps publishes updated assessments. The weather forecast refreshes throughout the day.
What does the Significant hazard rating mean?
The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card below for the full definitions.
What's "% of normal"?
The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).
Can I get alerts when storage crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app. Favorite this dam, set a threshold, and you'll get a push the moment conditions cross.
Dam data reference
Condition Assessment
- Satisfactory
- No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
- Fair
- No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action.
- Poor
- A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency.
- Unsatisfactory
- A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
- Not Rated
- The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Hazard Potential Classification
- High
- Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
- Significant
- Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environmental damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
- Low
- Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
- Undetermined
- Dams for which a downstream hazard potential has not been designated or is not provided.