Sublett

Sublett is a dam located in Cassia County, Idaho, built in 1914. It carries a High hazard potential classification and has a fair condition assessment.

About Sublett

The primary purpose of Sublett is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is private-owned. It impounds the Sublett Creek Sinks near Sublett.

The dam stands 48 feet tall and stretches 600 feet across, creates a reservoir covering 98 acres, has a storage capacity of 2,400 acre-feet, and collects water from a drainage area of 46 square miles. Completed in 1914, the structure is over a century old.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 05/21/2020.

At 48 feet, this dam is taller than 92% of dams nationwide.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Idaho dam safety program can provide more specific information about emergency planning for this structure.

Search for dams near your address to see all dams in your area with hazard classifications and safety data.

High HazardFair ConditionEmergency Action Plan: Yes

Location

StateIdaho
CountyCassia
Nearest CitySublett
River/StreamSublett Creek Sinks
Coordinates42.32490, -113.04670

Physical Characteristics

NID Height48 ft
Dam Height48 ft
Dam Length600 ft
Year Completed1914 (112 years old)

Storage & Hydraulics

NID Storage2,400 acre-ft
Normal Storage2,400 acre-ft
Surface Area98 acres
Drainage Area46 sq mi
Max Discharge385 cfs
Spillway TypeUncontrolled

Ownership & Safety

PurposeIrrigation
Owner TypePrivate
Hazard ClassificationHigh
Condition AssessmentFair
Last Inspection05/21/2020
Emergency Action PlanYes

Identifiers

NID IDID00031
Federal IDID00031
More InfoState Dam Safety Program