Walling Subwatershed Sta 77+50 #1 Reservoir Report
Last Updated: December 13, 2025
Located in Woodbury County, Iowa, the Walling Subwatershed Sta 77+50 #1 serves multiple purposes, including fire protection, stock maintenance, and small fish pond management.
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Summary
Built in 1953, this earth dam stands at a height of 48 feet and stretches for 550 feet, with a storage capacity of 95 acre-feet. Situated along the TR-Little Sioux River, this dam plays a crucial role in flood risk reduction for the surrounding area.
Managed by the USDA NRCS and regulated by the Iowa DNR, this dam has a low hazard potential and is currently deemed to be in "not rated" condition. Despite its moderate risk assessment score of 3, the Walling Subwatershed Sta 77+50 #1 has not undergone recent inspections or condition assessments. With a drainage area of 0.33 square miles and a surface area of 4.2 acres, this dam provides essential water resource management for the community of OTO and beyond.
Even though this dam is uncontrolled by a spillway, the Walling Subwatershed Sta 77+50 #1 remains a vital infrastructure for maintaining water resources and mitigating flood risks in the region. As climate change continues to impact water availability and extreme weather events, the importance of well-maintained dams like this one cannot be overstated for ensuring the resilience of local communities and ecosystems in the face of a changing climate.
Year Completed |
1953 |
Dam Length |
550 |
Dam Height |
48 |
River Or Stream |
TR-LITTLE SIOUX RIVER |
Primary Dam Type |
Earth |
Surface Area |
4.2 |
Drainage Area |
0.33 |
Nid Storage |
95 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
48 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Little Sioux River At Correctionville
|
327cfs |
Maple River At Mapleton
|
323cfs |
West Fork Ditch At Hornick
|
80cfs |
Little Sioux River Near Turin
|
1040cfs |
Monona-Harrison Ditch Near Turin
|
158cfs |
Floyd River At James
|
187cfs |
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.
Walling Subwatershed Sta 77+50 #1