St. Marys Lake

SILVER CREEK-OS· Clear Creek, Colorado· Built 1889· Earth· 9 ft tall

Key Takeaway

St. Marys Lake is classified as significant hazard in Colorado. It was completed in 1889 and is 137 years old. Its primary use is water supply. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 9 ft (taller than 2.9% in CO)
Dam Length210 ft
Dam TypeEarth
Max Storage51 acre-ft
Normal Storage38 acre-ft
Surface Area7 acres
Drainage Area0 sq mi
Max Discharge220 cfs
Year Completed1889 (137 years old)
Year Modified2000
NID IDCO01188

Safety Information

Significant Hazard

No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities.

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

Emergency Action Plan: Yes
Last Inspection: September 28, 2022
State Regulated: Yes
Regulatory Agency: DWR

Ownership

COORS BREWING CO. LAND & WATER RESOURCES (SANTANGE

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of St. Marys Lake?

St. Marys Lake is classified as Significant Hazard. No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates St. Marys Lake?

St. Marys Lake is owned by COORS BREWING CO. LAND & WATER RESOURCES (SANTANGE (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was St. Marys Lake built?

St. Marys Lake was completed in 1889, making it 137 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 St. Marys Lake?

St. Marys Lake serves the following purposes: Water Supply, Fire Protection, Stock, Or Small Fish Pond, Irrigation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is St. Marys Lake?

St. Marys Lake has a dam height of 9 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 St. Marys Lake last inspected?

St. Marys Lake was last inspected on September 28, 2022. 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.