Grasmere Middle Dam

RATTLESNAKE CREEK MARYS CREEK· Owyhee, Idaho· Built 1936· 16 ft tall
Low Hazard Other Private

Key Takeaway

Grasmere Middle Dam is classified as low hazard in Idaho. It was completed in 1936 and is 90 years old. Its primary use is other.

Physical Details

Dam Height 16 ft (taller than 13.6% in ID)
Dam Length700 ft
Normal Storage420 acre-ft
Surface Area153 acres
Drainage Area1 sq mi
Max Discharge18 cfs
Year Completed1936 (90 years old)
NID IDID00411

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: August 27, 2020
State Regulated: Yes
Regulatory Agency: IDWR

Ownership

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Grasmere Middle Dam?

Grasmere Middle Dam 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 Grasmere Middle Dam?

Grasmere Middle Dam is owned by information not available (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Grasmere Middle Dam built?

Grasmere Middle Dam was completed in 1936, making it 90 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 Grasmere Middle Dam?

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

How tall is Grasmere Middle Dam?

Grasmere Middle Dam has a dam height of 16 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 Grasmere Middle Dam last inspected?

Grasmere Middle Dam was last inspected on August 27, 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.