Many visitors to Sardis Lake do not know of the lake's main purpose. To them, Sardis Lake is a place to play, fish, camp, or maybe even geocache. However, this lake serves another very important purpose - flood control. The dam constructed here protects agricultural and industrial areas downstream by controlling the flow of water from the Little Tallahatchie River.
This EarthCache deals with the aspect of Earth Science involving the hydrological processes which have shaped the landscape of this site. Look at the 2 photos of the river bed posted below.These were taken before the dam was completed. Compare them to the view you see at the EarthCache site today, and you will get an understanding of how drastically the landscape has changed, and how these processes have affected the surrounding area.
In 1936, President Franklin D. Roosevelt signed the Flood Control Act of 1936. Sardis Dam was the first of the Yazoo Headwaters Projects to be built. Construction took four years and required thousands of men to clear fourteen miles along the Little Tallahatchie River, which was characterized by dense woods and undergrowth, and meandering sloughs.
The most distinctive aspect of the dam's construction was the use of "hydraulic fill" techniques. This required that soil be dredged from the river below the dam site and pumped up to provide the earth fill that forms the major portion of the dam. To accomplish this, the US Army Corps of Engineers built and operated the "Pontotoc," a special dredge powered by two 3,000 hp electric motors. This created the 400-acre “Lower Lake” of Sardis on the downstream side of Sardis Dam.
During the fall and winter months, the lake is gradually drawn down to a "conservation pool". This allows for storage of spring rains to fill the drainage area above the dam, forming the main area of Sardis Lake. Since it became operational, the dam's emergency spillway has only been overtopped three times by unprecedented high water in 1973, 1983 and 1991.
The requirement to log this cache is that you email the cache owner the answers to the following questions. DO NOT post them in your log, or your log will be removed. Answers can be found on 2 different markers located at the Sardis Lake Dam Overlook. To answer question 4 & 5, proceed below the dam and park at the spillway. Coordinates for these answers are listed as an additional waypoint. Requirements:
1. What is the maximum height of the dam?
2. What is the size of the drainage basin located above the dam?
3. How much water can the drainage basin hold at max flood pool?
4. What is the current water level below the spillway? To do this proceed to the additional listed waypoint. Look on the south side wall below the spillway. You will see water level markers that will indicate the current level.
5. Describe the amount of water currently being released into the Lower Lake by the spillway? (Example - is the spillway closed or open? Is there much current flowing downstream?)
6. (Optional) Please post a photo of you and your GPS at the Sardis Lake Dam.