Moonan Marsh dam
Moonan Marsh
Moonan Marsh, located in Waseca, Minnesota, is a gravity dam built in 1967 by the USDA NRCS with a primary purpose of "Other." It stands at a height of 13 feet and has a normal storage capacity of 100 acre-feet. The dam is situated on Crane Creek in Clinton Falls and covers a drainage area of 33 square miles.
Managed by the Minnesota Department of Natural Resources, Moonan Marsh is regulated, inspected, and permitted by the state, ensuring its safety and compliance with environmental standards. With a low hazard potential and satisfactory condition assessment, the dam poses minimal risk to the surrounding area. Despite its uncontrolled spillway and outlet gates, the structure has been deemed safe and is monitored regularly to maintain its integrity.
Moonan Marsh serves as a vital resource for water conservation and climate management in the region. Its modest size and controlled discharge contribute to moderate risk management measures, allowing for the sustainable utilization of water resources in the area. As a testament to responsible stewardship, Moonan Marsh stands as a symbol of the importance of maintaining and regulating water infrastructure for the benefit of both the environment and local communities.
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.
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 Moonan Marsh -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Straight River Near Faribault | 286 cfs | → |
| Minnesota River At Mankato | 11,300 cfs | → |
| Le Sueur River Near Rapidan | 3,650 cfs | → |
| Blue Earth River Near Rapidan | 3,920 cfs | → |
| Watonwan River Near Garden City | 1,380 cfs | → |
| Cedar River Near Austin | 173 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Moonan Marsh.
Boat launches
- Maplewood Boat Ramp
- Timber Doodle Trail Le Sueur County
- Morristown Boulevard 22200, Rice County
- Roots Beach Road 8, Elysian
- Boat Ramp Faribault
- County Road 12 Le Sueur County
Campgrounds
- Sakatah Lake State Park Campground
- Sakatah Lake State Park
- Scotts Campground
- Hope Oak Knoll Campground
- Rice Lake State Park
- Bray County Park
More reservoirs
Track Moonan Marsh in the Snoflo app
Save this dam as a favorite and get the local NOAA / yr.no forecast plus regional flow context wherever you are.
About Moonan Marsh
Where does the data for Moonan Marsh 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 Low 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 above 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.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Moonan Marsh.