Alpine Dam

KEITH CREEK· Winnebago, Illinois· Built 1942· Earth· 48 ft tall
High Hazard Flood Risk Reduction Local Government

Key Takeaway

Alpine Dam is classified as high hazard in Illinois. It was completed in 1942 and is 84 years old. Its primary use is flood risk reduction. High hazard means loss of life is likely if the dam fails — it does not indicate the dam's current condition. Learn more.

Physical Details

Dam Height 48 ft (taller than 90.6% in IL)
Dam Length600 ft
Dam TypeEarth
Max Storage1.8K acre-ft
Normal Storage0 acre-ft
Drainage Area7 sq mi
Max Discharge17,429 cfs
Year Completed1942 (84 years old)
NID IDIL00109

Safety Information

High Hazard

Loss of human life is likely if the dam fails.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: Yes
Last Inspection: August 9, 2021
State Regulated: Yes
Regulatory Agency: IDNR

Ownership

CITY OF ROCKFORD

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Alpine Dam?

Alpine Dam is classified as High Hazard. Loss of human life is likely if the dam fails. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Alpine Dam?

Alpine Dam is owned by CITY OF ROCKFORD (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Alpine Dam built?

Alpine Dam was completed in 1942, making it 84 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.

What is the primary purpose of Alpine Dam?

Alpine Dam serves the following purposes: Flood Risk Reduction. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Alpine Dam?

Alpine Dam has a dam height of 48 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.

When was Alpine Dam last inspected?

Alpine Dam was last inspected on August 9, 2021. Inspection dates indicate when a formal review occurred, not the results of that inspection.

Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.