Grade Lake Dam dam
Grade Lake Dam
Grade Lake Dam, located in Osceola, Iowa, is a vital water resource structure designed by CB&Q RR and Ray Henley in 1900. With a height of 44 feet and a length of 1300 feet, this earth dam serves the primary purpose of recreation, offering a surface area of 25.7 acres for leisure activities. The dam's reservoir provides a normal storage capacity of 217 acre-feet and a maximum storage of 865 acre-feet, making it a significant water source in the region.
Managed by the Iowa Department of Natural Resources, Grade Lake Dam is regulated, inspected, and enforced by state authorities to ensure its safety and functionality. The dam's spillway type is uncontrolled, with a width of 4 feet, while its hazard potential is classified as high, signaling the need for regular monitoring and risk management measures. Despite its moderate risk assessment, the dam's condition is deemed satisfactory as of the last inspection in May 2019, highlighting its importance in water resource management and climate resilience efforts in the area.
Water resource and climate enthusiasts can appreciate Grade Lake Dam as a key infrastructure supporting recreational activities and water storage in Clarke County, Iowa. As a state-regulated dam with a significant storage capacity and high hazard potential, its management and maintenance play a crucial role in ensuring public safety and environmental sustainability. With a rich history dating back to the early 20th century, Grade Lake Dam stands as a symbol of resilience and innovation in water resource engineering, serving as a valuable asset in the region's efforts to adapt to changing climate conditions and enhance water security.
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 Grade Lake Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Thompson River At Davis City | 120 cfs | → |
| South River Near Ackworth | 51 cfs | → |
| Chariton River Near Chariton | 4 cfs | → |
| Middle River Near Indianola | 206 cfs | → |
| White Breast Creek Near Dallas | 26 cfs | → |
| North River Near Norwalk | 200 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Grade Lake Dam.
Boat launches
- Us 34 Clarke County
- Pershing Street Warren County
- 118th Avenue Warren County
- Red Haw Nature Trail Lucas County
- Decatur County
Track Grade 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 Grade Lake Dam
Where does the data for Grade 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 High 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 Grade Lake Dam.