Mass Dam Reservoir Report
Nearby: Goos-Miller Dam Schultz/Blumer Dam
Last Updated: December 13, 2025
Located in Mills County, Iowa, Mass Dam is a privately owned structure designed by the USDA NRCS and completed in 1959.
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Summary
This earth-type dam stands at a height of 28 feet and spans 307 feet, with a storage capacity of 41 acre-feet. Its primary purpose is for fire protection, stock, or as a small fish pond, serving the local community of Silver City. The dam is state-regulated and falls under the jurisdiction of the Iowa Department of Natural Resources, with permitting, inspection, and enforcement processes in place.
With a low hazard potential and a moderate risk assessment rating, Mass Dam has not been rated for its condition. It features an uncontrolled spillway type and has a drainage area of 0.29 square miles. The dam has not been modified in recent years and has not undergone a condition assessment. While emergency action plans and risk management measures are not specified, the dam's risk level is considered moderate. Although it is not owned or funded by federal agencies, it has received design support from the Natural Resources Conservation Service.
Despite its relatively small size, Mass Dam plays a crucial role in local water resource management and provides essential services to the community. With its strategic location on the TR-Silver Creek, the dam contributes to fire protection, livestock watering, and recreational fishing opportunities. As climate change continues to impact water resources, structures like Mass Dam will be increasingly vital for ensuring sustainable water use and conservation in the future.
Year Completed |
1959 |
Dam Length |
307 |
Dam Height |
28 |
River Or Stream |
TR-SILVER CREEK |
Primary Dam Type |
Earth |
Surface Area |
2.8 |
Drainage Area |
0.29 |
Nid Storage |
41 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
28 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Missouri River At Omaha
|
17700cfs |
West Nishnabotna River At Hancock
|
154cfs |
West Nishnabotna River At Randolph
|
420cfs |
East Nishnabotna River At Red Oak
|
270cfs |
Big Papillion Cr
|
38cfs |
East Nishnabotna River Near Atlantic
|
143cfs |
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.
Area Campgrounds
| Location | Reservations | Toilets |
|---|---|---|
Olde Towne Co Park
|
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Carson City Park
|
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Glenwood Lake Park
|
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Pony Creek Co Park
|
Mass Dam