Summary
Completed in 1970, this earth dam stands at a height of 22 feet and spans a length of 834 feet, with a storage capacity of 132 acre-feet. Situated on the TR-Little Rock River, the dam serves as a recreational area and plays a crucial role in water resource management in the region.
Managed by the Iowa DNR, Jansma Dam is regulated, inspected, and enforced by the state to ensure its safety and functionality. With a low hazard potential and a moderate risk assessment score of 3, the dam has not been rated for its condition, but it meets guidelines for emergency action planning. Despite its uncontrolled spillway and limited drainage area, the dam continues to provide essential benefits for fire protection, stock watering, and recreational activities in the area.
Overall, Jansma Dam serves as a vital infrastructure for water resource management and climate resilience in Lyon County. With its strategic location, design, and operational mechanisms, the dam contributes to the local community's water needs while also offering opportunities for leisure and recreation. As climate enthusiasts and water resource advocates, understanding and monitoring structures like Jansma Dam are crucial for ensuring sustainable water management practices and adapting to changing environmental conditions in the region.
Year Completed |
1970 |
Dam Length |
834 |
Dam Height |
22 |
River Or Stream |
TR-LITTLE ROCK RIVER |
Primary Dam Type |
Earth |
Surface Area |
8.2 |
Drainage Area |
0.69 |
Nid Storage |
132 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
22 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
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.
Jansma Dam