Grass Lake Dam dam
Grass Lake Dam
Grass Lake Dam, located in Benzie County, Michigan, is a gravity dam on the Betsie River that was completed in 1951 for recreational purposes. With a height of 8.4 feet and a hydraulic height of 5.4 feet, the dam has a storage capacity of 5200 acre-feet and a normal storage level of 675 acre-feet. The dam spans 176 feet in length and covers a surface area of 482 acres, serving as a popular spot for outdoor enthusiasts in the Wallin area.
Despite being categorized as having a low hazard potential and a satisfactory condition assessment as of 2014, the dam is subject to moderate risk (3) due to its location and structure. The spillway, with a width of 62 feet, is uncontrolled, allowing for a maximum discharge of 1600 cubic feet per second. The dam is not regulated by the state and has not been inspected or permitted by state agencies, indicating a lack of oversight in its maintenance and operation.
Given its historical significance and recreational value, Grass Lake Dam serves as both a landmark and a potential area of concern for water resource and climate enthusiasts. Its location on the Betsie River and the surrounding Benzie County landscape make it a critical piece of infrastructure to monitor and maintain to ensure the safety and sustainability of the local ecosystem and community.
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 Grass Lake Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Platte River At Honor | 162 cfs | → |
| Manistee River Near Sherman | 1,660 cfs | → |
| Manistee River Near Mesick | 1,500 cfs | → |
| Boardman R Above Brown Bridge Road Nr Mayfield | 218 cfs | → |
| Manistee River Near Wellston | 2,430 cfs | → |
| Pine River At High School Bridge Nr Hoxeyville | 289 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Grass Lake Dam.
Boat launches
- Bronson Lake Access Almira Township
- South Buckley Road Mayfield Township
- Lake Ann Launch Site Road Almira Township
- Fishing Site Road 6998, Long Lake Township
- Herendeen Lake Access Almira Township
- Silver Lake Public Boat Launch
Campgrounds
- Grass Lake State Forest Campground
- Interlochen Green Lake Rustic Campground
- Lake Dubonnet Trail Camp - State Forest
- Platte River State Forest Campground
- Lake Ann State Forest Campground
- Garey Lake Trail Camp - State Forest
Fishing spots
Paddle runs
- Southern Boundary Of Sleeping Bear Dunes National Lakeshore To Mouth At Lake Michigan
- Southeastern Boundary Of Sleeping Bear Dunes National Lakeshore To Northwetern Boundary Of Sleeping Bear Dunes National Lakeshore
- Kings Road Bridge (2 Miles West Of Town Of Luther In T19n, R12w To Slackwater Of The State Fish Weir In T21n, R16w
Track Grass Lake 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 Grass Lake Dam
Where does the data for Grass Lake 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 Grass Lake Dam.