Grand Ledge Dam dam
Grand Ledge Dam
The Grand Ledge Dam, also known as Mudge Dam, is a gravity dam located on the Grand River in Portland, Eaton County, Michigan. Built in 1900, the dam stands at a height of 8 feet and stretches 292 feet in length, with a maximum storage capacity of 1200 acre-feet. Its primary purpose is for recreation, offering a picturesque spot for water enthusiasts and nature lovers to enjoy.
Despite its age, the Grand Ledge Dam has a low hazard potential and a very high risk assessment rating, indicating the need for ongoing monitoring and maintenance. The dam features a controlled spillway with a width of 290 feet, capable of handling a maximum discharge of 9000 cubic feet per second. While not currently regulated or inspected by the state, the dam remains a popular destination for outdoor activities and serves as a vital part of the local ecosystem.
As climate change continues to impact water resources and infrastructure, the Grand Ledge Dam stands as a reminder of the importance of sustainable water management practices. Its historical significance and recreational value make it a cherished landmark in the community, attracting visitors from near and far to witness the beauty and power of the Grand River.
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 Grand Ledge Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Looking Glass River Near Eagle | 160 cfs | → |
| Grand River At Portland | 1,070 cfs | → |
| Grand River At Lansing | 877 cfs | → |
| Red Cedar River At East Lansing | 166 cfs | → |
| Sycamore Creek At Holt Road Near Holt | 41 cfs | → |
| Grand River Near Eaton Rapids | 1,400 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Grand Ledge Dam.
Boat launches
- North Clinton Street Grand Ledge
- Moores River Drive Lansing
- Alliance Drive Potterville
- Howe Road Dewitt Charter Township
- West Saint Joseph Highway Sunfield Township
Campgrounds
- Eaton County Fairgrounds
- Maple River Campground
- Sleepy Hollow State Park
- Ionia Equestrian-Rustic
- Ionia State Rec Area
- Bertha Brock County Park
Fishing spots
Track Grand Ledge Dam 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 Grand Ledge Dam
Where does the data for Grand Ledge Dam 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 Grand Ledge Dam.