Twin Lakes No. 1

CONEY CREEK· Sheridan, Wyoming· Built 1998· Earth· 84 ft tall
High Hazard Water Supply Local Government

Key Takeaway

Twin Lakes No. 1 is classified as high hazard in Wyoming. It was completed in 1998 and is 28 years old. Its primary use is water supply. 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 84 ft (taller than 97.7% in WY)
Dam Length1,835 ft
Dam TypeEarth
Max Storage4.0K acre-ft
Normal Storage3.4K acre-ft
Surface Area81 acres
Drainage Area8 sq mi
Max Discharge13,540 cfs
Year Completed1998 (28 years old)
NID IDWY00647

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: June 18, 2020
State Regulated: Yes
Regulatory Agency: SEO

Ownership

CITY OF SHERIDAN - TOM MANOLIS

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Twin Lakes No. 1?

Twin Lakes No. 1 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 Twin Lakes No. 1?

Twin Lakes No. 1 is owned by CITY OF SHERIDAN - TOM MANOLIS (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Twin Lakes No. 1 built?

Twin Lakes No. 1 was completed in 1998, making it 28 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 Twin Lakes No. 1?

Twin Lakes No. 1 serves the following purposes: Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Twin Lakes No. 1?

Twin Lakes No. 1 has a dam height of 84 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 Twin Lakes No. 1 last inspected?

Twin Lakes No. 1 was last inspected on June 18, 2020. 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.