Tyer Dam Reservoir Report
Last Updated: December 13, 2025
Tyer Dam, located in Woodbury County, Iowa, is a privately owned structure completed in 1997 with a primary purpose of fire protection, as well as serving as a stock or small fish pond.
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Summary
The dam, designed by NRCS, is an earth dam standing at 22 feet in height and stretching 856 feet in length. It has a storage capacity of 90 acre-feet, with a normal storage level of 33 acre-feet and a surface area of 6.6 acres.
Managed and regulated by the Iowa Department of Natural Resources, Tyer Dam is considered to have a low hazard potential with a moderate overall risk assessment. While the dam does not have a designated emergency action plan (EAP) in place, it meets regulatory guidelines for inspection, enforcement, and permitting. The structure is situated on TR-Deer Creek and falls under the jurisdiction of the state of Iowa for oversight and maintenance.
For water resource and climate enthusiasts, Tyer Dam offers a unique opportunity to study the impact of small-scale dams on local ecosystems and water management practices. With its low hazard potential and moderate risk assessment, the dam provides a fascinating case study for understanding the role of privately owned structures in maintaining water resources for fire protection and agricultural needs in the region.
Year Completed |
1997 |
Dam Length |
856 |
Dam Height |
22 |
River Or Stream |
TR- DEER CREEK |
Primary Dam Type |
Earth |
Surface Area |
6.6 |
Drainage Area |
0.37 |
Nid Storage |
90 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
22 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
West Fork Ditch At Hornick
|
80cfs |
Floyd River At James
|
187cfs |
Missouri River At Sioux City
|
15100cfs |
Little Sioux River At Correctionville
|
327cfs |
Omaha Cr At Homer
|
45cfs |
Perry Creek Near Milnerville
|
25cfs |
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.
Tyer Dam