Environmental Services Inc. was selected to restore and construct a first order stream type within the Legacy Farms Mitigation Bank just outside of Gray, Georgia. The project provides for the restoration and rehabilitation of Unnamed Tributary 1 which originates at a spring near the north-western property limits. The channel traverses approximately 300 feet as a small, narrow, and slightly incised channel. A severe head-cut, that drops the channel bed approximately 10 feet, then encumbers the channel making it severely incised. The $125,000 project is funded by Legacy Farms Stream bank, LLC and will generate approximately 17,000 stream mitigation credits. The project includes rehabilitating the spring and naturalizing the stream running through the valley. Unnamed Tributary 1 is part a tributary of Walnut Creek and is in the Upper Ocmulgee Watershed.
The proposed restoration will narrow up the initial 300-linear feet of channel then, relocated it to the flood prone area adjacent to the existing left bank. Over the next 1000 feet the new channel was designed to be a mosaic of Rosgen C, E, and B-channel types. The initial bankfull width was adjusted to 3.0 feet. Through-out this stream segment riffle-pool complexes were not constructed. Narrow, spring-fed sand-bottomed streams do not exhibit the typical riffle-pool pattern. As the channel widens to carry increased flow, then these complexes form. The proposed design attempted to mimic this by slightly increasing the channel bankfull width at appropriate distances within the watershed. Further downstream the restoration treatment included the placement of grade and bank-control structures, creation of proper plan form and dimension requirements.
In total, approximately 200 tons of rock boulders, and 50 root wads and trees were used to construct 20 cross vanes, 13 j-hooks, 8 step pools, 1 w-weir and other outlet control structures associated with the project. Approximately 2,300 linear feet of stream channel was excavated and allowed access to its floodplain.
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