Zellmer Subwtrshd Sta 54+60 #B1 Reservoir Report
Last Updated: December 14, 2025
Zellmer Subwtrshd Sta 54+60 #B1 is a local government-owned dam in Woodbury County, Iowa, designed by USDA NRCS and regulated by the Iowa DNR.
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Summary
Completed in 1964, this earth dam serves multiple purposes, including fire protection, stock, small fish pond, and flood risk reduction. With a height of 30 feet and a length of 557 feet, the dam has a storage capacity of 84 acre-feet and covers a surface area of 4.4 acres, draining a watershed area of 0.51 square miles.
Located in ROLLY SPRINGS along the TR-WEST FORK LITTLE SIOUX RIV, this dam has a low hazard potential and a moderate risk assessment rating. While the condition assessment is not rated, the dam meets state permitting, inspection, and enforcement requirements. The spillway type is uncontrolled, with no outlet gates or locks present. The dam is primarily used for water resource management, and its risk management measures are unspecified.
Overall, Zellmer Subwtrshd Sta 54+60 #B1 is an essential infrastructure for the local community, providing critical services such as fire protection and flood risk reduction. As climate change impacts water resources, the proper maintenance and management of dams like this one become increasingly important for ensuring the safety and sustainability of water sources in the area.
Year Completed |
1964 |
Dam Length |
557 |
Dam Height |
30 |
River Or Stream |
TR-WEST FORK LITTLE SIOUX RIV |
Primary Dam Type |
Earth |
Surface Area |
4.4 |
Drainage Area |
0.51 |
Nid Storage |
84 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
30 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
West Fork Ditch At Hornick
|
80cfs |
Floyd River At James
|
187cfs |
Missouri River At Sioux City
|
13700cfs |
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.
Zellmer Subwtrshd Sta 54+60 #B1