Hamaker Dam Reservoir Report
Nearby: Riggleman Dam Moller/Frahm Dam
Last Updated: December 14, 2025
Located in Crawford, Iowa, Hamaker Dam is a privately owned earth dam constructed in 1961 by the USDA NRCS.
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Summary
With a height of 30 feet and a length of 410 feet, the dam serves multiple purposes including fire protection and creating a small fish pond. Situated on the TR-Boyer River, the dam has a storage capacity of 77 acre-feet and covers a surface area of 4 acres, providing essential water resources for the local community.
Managed by the Iowa Department of Natural Resources, Hamaker Dam is regulated, permitted, inspected, and enforced to ensure its structural integrity and safety. Despite being classified as having a low hazard potential, the dam is rated as not assessed for its condition. With a moderate risk assessment score of 3, the dam is closely monitored for any potential risks or vulnerabilities, although specific risk management measures have not been outlined.
Water resource and climate enthusiasts can appreciate the significance of Hamaker Dam in providing essential water storage for fire protection and recreational activities in the area. As a key structure in the region, the dam stands as a testament to effective water management practices and serves as a vital resource for both the community and the environment.
Year Completed |
1961 |
Dam Length |
410 |
Dam Height |
30 |
River Or Stream |
TR-BOYER RIVER |
Primary Dam Type |
Earth |
Surface Area |
4 |
Drainage Area |
0.51 |
Nid Storage |
77 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
30 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
North Raccoon River Near Sac City
|
312cfs |
Maple River At Mapleton
|
323cfs |
Little Sioux River At Correctionville
|
327cfs |
Little Sioux River Near Turin
|
1040cfs |
Monona-Harrison Ditch Near Turin
|
158cfs |
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.
Hamaker Dam