Iola Reservoir Report
Nearby: Scandinavia Ogdensburg
Last Updated: December 6, 2025
Situated in Waupaca, Wisconsin, the Iola dam stands as a significant water resource managed by the local government for recreational purposes.
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Summary
Completed in 1865, this gravity dam on the South Branch Little Wolf River boasts a height of 12 feet and a length of 694 feet, providing a storage capacity of 1000 acre-feet and a normal storage level of 638 acre-feet. With a surface area of 206 acres and a drainage area of 100 square miles, the dam has a maximum discharge capacity of 810 cubic feet per second.
Despite its fair condition assessment as of May 2020, the Iola dam poses a significant hazard potential, leading to a very high risk assessment rating of 1. The dam's inspection frequency of every 3 years ensures its ongoing maintenance and safety compliance. With state regulation, permitting, inspection, and enforcement in place by the Wisconsin Department of Natural Resources, the dam remains a vital structure for both water resource management and recreational activities in the region.
Notably, the Iola dam has undergone modifications in 1947 and 2013, indicating a commitment to its structural integrity and functionality. With a controlled spillway and a designated emergency action plan, the dam's risk management measures are designed to mitigate potential threats and safeguard the surrounding community. As climate change continues to impact water resources, the Iola dam stands as a crucial infrastructure for both environmental sustainability and public safety in the face of evolving hydrological challenges.
Years Modified |
1947 - Other, 2013 - Other |
Year Completed |
1865 |
Dam Length |
694 |
Dam Height |
12 |
River Or Stream |
SOUTH BRANCH LITTLE WOLF |
Primary Dam Type |
Gravity |
Surface Area |
206 |
Hydraulic Height |
8 |
Drainage Area |
100 |
Nid Storage |
1000 |
Structural Height |
12 |
Hazard Potential |
Significant |
Nid Height |
12 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Tomorrow River Near Nelsonville
|
25cfs |
Waupaca River Near Waupaca
|
431cfs |
Little Wolf River At Royalton
|
-999999cfs |
Wolf River At New London
|
1050cfs |
Embarrass River Near Embarrass
|
288cfs |
Red River At Morgan Road Near Morgan
|
145cfs |
Dam Data Reference
Condition Assessment
SatisfactoryNo 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. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
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. Investigations and studies are necessary.
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.
Not Available
Dams for which the condition assessment is restricted to approved government users.
Hazard Potential Classification
HighDams 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, environment 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.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.
Area Campgrounds
| Location | Reservations | Toilets |
|---|---|---|
Lake Emily South Campground
|
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Lake Emily Park North Campground
|
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Camp Onaway
|
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Collins Park
|
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Collins Park Campground
|
Iola
Iola Lake -- Access