Lake Ouachita in west-central Arkansas is the largest man-made reservoir in the state. The lake was created by the U.S. Army Corps of Engineers (USACE) in 1953 for the purposes of hydropower, flood control, and recreation. Although Lake Ouachita is widely known for its high water clarity near Blakely Dam, little is known about the volume and ultimate fate of sediments that enter the lake from two primary tributaries: the North and South Forks of the Ouachita River. This project utilized a dual-frequency echo sounding system in combination with geographic information system and statistical analysis to calculate an average post-impoundment sediment thickness of approximately 0.78 m present throughout the study area, with a maximum sediment thickness of 2.93 meters. The total volume of post-impoundment sediment in place was calculated as 2,750,000 m and the average linear sediment accumulation rate was determined to be 1.3 cm y-1. Variations within the project area show widespread sediment focusing with statistically significant variations in sediment thickness between littoral and deeper zones, as well as between the lotic-transitional and lacustrine zones

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