Porcupine

PORCUPINE CREEK· Converse, Wyoming· Built 1979· Earth· 35 ft tall
Low Hazard Irrigation Private

Key Takeaway

Porcupine is classified as low hazard in Wyoming. It was completed in 1979 and is 47 years old. Its primary use is irrigation.

Physical Details

Dam Height 35 ft (taller than 78.8% in WY)
Dam Length1,450 ft
Dam TypeEarth
Max Storage865 acre-ft
Normal Storage590 acre-ft
Surface Area70 acres
Drainage Area0 sq mi
Max Discharge390 cfs
Year Completed1979 (47 years old)
NID IDWY00733

Safety Information

Low Hazard

No probable loss of human life and low economic/environmental losses expected.

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

Emergency Action Plan: No
Last Inspection: September 27, 2023
State Regulated: Yes
Regulatory Agency: SEO

Ownership

POWDER RIVER COAL CO.

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Porcupine?

Porcupine is classified as Low Hazard. No probable loss of human life and low economic/environmental losses expected. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Porcupine?

Porcupine is owned by POWDER RIVER COAL CO. (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Porcupine built?

Porcupine was completed in 1979, making it 47 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 Porcupine?

Porcupine serves the following purposes: Irrigation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Porcupine?

Porcupine has a dam height of 35 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 Porcupine last inspected?

Porcupine was last inspected on September 27, 2023. 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.