Lannom Dam Reservoir Report
Nearby: Van Wyk/Vogel Dam Hudnutt Dam
Last Updated: December 6, 2025
Lannom Dam, located in Union Mills, Poweshiek County, Iowa, is a private dam designed by the USDA NRCS for fire protection, stock, or small fish pond purposes.
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Summary
Completed in 1990, this earth dam stands at a height of 30 feet and spans 400 feet in length, with a storage capacity of 141 acre-feet and a surface area of 10.1 acres. The dam is regulated by the Iowa Department of Natural Resources and undergoes regular inspections, enforcement, and permitting to ensure its safety and compliance with state regulations.
Situated on TR- Sugar Creek, Lannom Dam serves as a crucial water resource for the surrounding area, with a low hazard potential and a moderate risk assessment rating. The dam has not been rated for its condition assessment, but it is monitored for any potential risks and management measures. Despite its uncontrolled spillway type, the dam has a relatively low risk level and is equipped to handle emergency situations, although specific emergency action plans are not currently in place. Overall, Lannom Dam plays a vital role in water management and conservation efforts in the region.
Owned and operated by a private entity, Lannom Dam is an essential infrastructure for water supply and management in Poweshiek County. With its strategic location and purpose, the dam provides valuable benefits for fire protection, livestock, and recreational fishing activities. As a key feature in the local landscape, Lannom Dam exemplifies the intersection of water resource management and climate adaptation, showcasing the importance of sustainable infrastructure development in safeguarding the environment and community well-being.
Year Completed |
1990 |
Dam Length |
400 |
Dam Height |
30 |
River Or Stream |
TR- SUGAR CREEK |
Primary Dam Type |
Earth |
Surface Area |
10.1 |
Drainage Area |
0.47 |
Nid Storage |
141 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
30 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Richland Creek Near Haven
|
12cfs |
Walnut Creek Near Hartwick
|
13cfs |
South Skunk River Near Oskaloosa
|
485cfs |
Timber Creek Near Marshalltown
|
37cfs |
Des Moines River Near Pella
|
1220cfs |
South Skunk River At Colfax
|
211cfs |
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 |
|---|---|---|
Rock Creek State Park
|
||
Kellogg RV Park
|
||
Diamond Lake County Park
|
Lannom Dam
Merrill Park
Rock Creek State Park
Kellogg RV Park