Big Blue Creek Reservoir Report

Last Updated: December 19, 2025

Big Blue Creek, also known as Big Blue Reservoir, is a privately owned water resource located in Owyhee, Idaho.


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Summary

This reservoir, completed in 1910, serves multiple purposes and has a storage capacity of 2,100 acre-feet. With a dam height of 34.4 feet and a hydraulic height of 28.5 feet, it plays a crucial role in managing the water resources of the area.

Managed by the Idaho Department of Water Resources, Big Blue Creek is regulated and inspected regularly to ensure its safety and functionality. The dam, primarily made of earth and stone, has a spillway width of 40 feet and an uncontrolled spillway type. Despite being classified as having a significant hazard potential, the dam is currently assessed to be in fair condition, with a moderate level of risk associated with its operation.

Water resource and climate enthusiasts can appreciate the historical significance and engineering marvel of Big Blue Creek. This reservoir, nestled in the remote wilderness of Idaho, stands as a testament to the ingenuity and foresight of early water management efforts in the region. As efforts continue to monitor and maintain its integrity, Big Blue Creek remains a vital component of the water infrastructure in Owyhee County, playing a key role in water supply and management for the surrounding area.

Year Completed

1910

Dam Length

1000

Dam Height

34.4

River Or Stream

BLUE CREEK OWYHEE RIVER

Surface Area

188

Hydraulic Height

28.5

Drainage Area

66

Nid Storage

2100

Outlet Gates

Slide (sluice gate)

Hazard Potential

Significant

Foundations

Rock, Soil

Nid Height

34
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.

Hazard Potential Classification

High
Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.