Flood Control

Two major missions of the Ouachita Project Lakes are Hydropower and Flood Control. 
Blakely Mountain Dam was authorized by the Flood Control Act approved December 22, 1944, which adopted the plan as set forth in House Document No. 647, 78th Congress, 2nd Session.  The lake formed by the dam was designated as Lake Ouachita by authority of Public Law No. 504, which was approved on July 11, 1952.  Blakely Mountain Dam is located on the Ouachita River in Garland County, Arkansas, approximately 10 miles northwest of Hot Springs, Arkansas. 

The project includes a zoned rolled-earth fill dam containing approximately 4 million cubic yards of material.  The crest of the dam is 205 feet above the valley, with an elevation of 616 (NGVD 29) and measuring 1,100 feet in length. Lake Ouachita extends 30 miles upstream of the dam and covers 40,000 acres at normal lake level elevation, around 578 (NGVD 29).  The Lake Ouachita watershed reaches into six counties, covering approximately 665,000 acres of land area.

Under normal conditions, water released from Lake Ouachita exits through Blakely Mountain Power Plant during power generation.  Blakely Mountain Power Plant operates two turbines capable of generating 84 MW. The flood tunnel is used for controlled flood water release and to fulfill downstream flow requirements. Blakely flood control releases are governed by downstream dams, Carpenter and Remmel, and other downstream flow limitations.

This project also has an emergency spillway west of Blakely Mountain at the entrance of the Spillway Recreation Area.  A concrete apron was constructed within a natural trough in the topography to act as an ungated spillway.  In the event that Lake Ouachita rises above elevation 592 (NGVD 29), flood water would exit through this spillway and flow down a natural drainage, entering Lake Hamilton downstream of Blakely Mountain Dam.  To date, the highest lake level was 590.1 on December 5, 1982.