Norlund 1 Reservoir Report
Last Updated: December 15, 2025
Norlund 1 is a privately owned earth dam located in Crawford County, Iowa, near East Boyer River.
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Summary
Built in 2005 by USDA NRCS, this structure serves primarily for flood risk reduction along a tributary to Rocky Run Creek. Standing at 19 feet high and spanning 605 feet in length, Norlund 1 has a storage capacity of 146 acre-feet and covers a surface area of 6.2 acres. Despite its low hazard potential, the dam is not currently rated for its condition and has not undergone recent inspection.
Managed by the Iowa DNR, Norlund 1 operates with state permitting, inspection, and enforcement measures in place. The dam features an uncontrolled spillway with a width of 20 feet and has no outlet gates. While no emergency action plan (EAP) or inundation maps have been prepared for this structure, it does have a moderate risk assessment rating of 3 out of 5. Its risk management measures and risk characterization summary are currently unspecified, indicating potential room for improvement in emergency preparedness and response planning for this facility.
Year Completed |
2005 |
Dam Length |
605 |
Dam Height |
19 |
River Or Stream |
Trib to Rocky Run Creek |
Primary Dam Type |
Earth |
Surface Area |
6.2 |
Drainage Area |
0.75 |
Nid Storage |
146 |
Outlet Gates |
None |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
19 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
North Raccoon River Near Sac City
|
312cfs |
Maple River At Mapleton
|
323cfs |
Little Sioux River Near Turin
|
1040cfs |
Soldier River At Pisgah
|
112cfs |
Monona-Harrison Ditch Near Turin
|
158cfs |
Little Sioux River At Correctionville
|
327cfs |
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.
Norlund 1