Arrowhead Lake Dam Reservoir Report
Last Updated: December 13, 2025
Arrowhead Lake Dam, located in Underwood, Iowa, is a vital water resource managed by the local government and regulated by the Iowa Department of Natural Resources.
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Summary
Built in 1959 by the USDA NRCS, this earth dam stands at a height of 47 feet and stretches 615 feet in length, serving primarily for fire protection and as a small fish pond. With a storage capacity of 348 acre-feet and a surface area of 15.7 acres, the dam plays a crucial role in managing water resources in the region.
Although Arrowhead Lake Dam has a low hazard potential and is currently rated as "Not Rated" in terms of condition assessment, it is subject to regular state inspections, permitting, and enforcement to ensure its safety and functionality. The dam is situated along the TR-Mosquito Creek and falls under the jurisdiction of the Omaha District of the USACE. While it has not undergone any significant modifications since its construction, the risk assessment for the dam is moderate, highlighting the importance of ongoing risk management measures to safeguard the surrounding community and environment.
For water resource and climate enthusiasts, Arrowhead Lake Dam offers a fascinating case study in sustainable water management and infrastructure development. As a key structure for fire protection and ecological preservation, the dam exemplifies the intersection of human ingenuity and environmental stewardship. With its storied history and ongoing regulatory oversight, Arrowhead Lake Dam stands as a symbol of our ongoing commitment to safeguarding our precious water resources in the face of a changing climate.
Year Completed |
1959 |
Dam Length |
615 |
Dam Height |
47 |
River Or Stream |
TR-MOSQUITO CREEK |
Primary Dam Type |
Earth |
Surface Area |
15.7 |
Drainage Area |
1.63 |
Nid Storage |
348 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
47 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
West Nishnabotna River At Hancock
|
154cfs |
Boyer River At Logan
|
417cfs |
Missouri River At Omaha
|
17700cfs |
East Nishnabotna River Near Atlantic
|
143cfs |
Big Papillion Cr
|
38cfs |
Soldier River At Pisgah
|
112cfs |
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.
Arrowhead Lake Dam