Upper Sterling Reservoir Report
Nearby: French Pond Dam Leo Johnson Lake Dam
Last Updated: December 13, 2025
Upper Sterling is a gravity dam located on Rock Creek in Rock Falls, Illinois.
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Summary
Built in 1907 by the U.S. Army Corps of Engineers, the dam serves multiple purposes, including flood risk reduction and hydroelectric power generation. With a height of 9.5 feet and a length of 1170 feet, Upper Sterling has a storage capacity of 7000 acre-feet and a maximum discharge of 23,000 cubic feet per second.
Managed by the Federal Energy Regulatory Commission, Upper Sterling is regulated by the Illinois Department of Natural Resources and undergoes regular inspections to ensure its structural integrity and safety. The dam has a low hazard potential and is equipped with an uncontrolled spillway and seven other controlled outlet gates. Its location in Whiteside County, Illinois, makes it a key asset for water resource management in the region, providing both flood protection and clean energy production.
Despite its age, Upper Sterling remains a vital infrastructure component in the area, with a moderate risk assessment rating. Its historic significance, combined with its continued functionality and regulatory oversight, underscores its importance in the water resource and climate management landscape. For enthusiasts interested in the intersection of water resources, climate resilience, and hydroelectric power, Upper Sterling stands out as a prime example of sustainable infrastructure development and management.
Year Completed |
1907 |
Dam Length |
1170 |
Dam Height |
9 |
River Or Stream |
Rock Creek |
Primary Dam Type |
Gravity |
Surface Area |
2400 |
Hydraulic Height |
9.5 |
Drainage Area |
8750 |
Nid Storage |
7000 |
Structural Height |
9 |
Outlet Gates |
Other Controlled - 7 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
10 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Rock River At Como
|
3350cfs |
Elkhorn Creek Near Penrose
|
44cfs |
Mississippi River At Clinton
|
25000cfs |
Rock River Near Joslin
|
4400cfs |
Big Bureau Creek At Princeton
|
8cfs |
Rock River At Byron
|
4300cfs |
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.
Upper Sterling