Blakely Mountain Dam Reservoir Report

Last Updated: December 5, 2025

Blakely Mountain Dam, also known as Lake Ouachita, is a federal-owned structure located in Mountain Pine, Arkansas.


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Summary

Completed in 1953, this earth dam stands at 226 feet high and serves multiple purposes including flood risk reduction, hydroelectric power generation, recreation, and water supply for the surrounding area. The dam, managed by the US Army Corps of Engineers, holds a maximum storage capacity of 3,760,700 acre-feet and spans 1,100 feet in length.

However, despite its crucial functions, Blakely Mountain Dam poses a high hazard potential due to the risk of overtopping during major storm events. A risk assessment conducted in 2020 classified the project's risks as moderate, with concerns about potential dam failure and downstream flooding in the event of reservoir overflow. To mitigate these risks, the USACE has implemented a comprehensive risk management plan that includes regular surveillance, monitoring, and inspection of the dam, as well as the installation of interim risk-reduction measures such as berms and seepage collection systems.

In addition to these measures, the USACE engages in community outreach, collaborates with local emergency managers, and conducts regular emergency exercises to ensure preparedness in the event of a dam-related incident. By prioritizing safety and proactive risk management strategies, Blakely Mountain Dam continues to play a vital role in protecting downstream communities while providing essential water resources and recreational opportunities for the region.

Years Modified

2009 - Other

Year Completed

1953

Dam Length

1100

Dam Height

226

River Or Stream

OUACHITA RIVER

Primary Dam Type

Earth

Surface Area

40100

Hydraulic Height

216

Drainage Area

1105

Nid Storage

3760700

Structural Height

240

Outlet Gates

Roller - 7, Vertical Lift - 4

Hazard Potential

High

Foundations

Rock

Nid Height

240
       
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.