Tiawasee Creek Stream Restoration
Size: 1,400 linear feat
In partnership with the Mobile Bay National Estuary Program and the City of Daphne, GMC successfully completed the restoration of approximately 1,400 linear feet of Tiawasee Creek in Daphne, Ala. Designed by GMC and constructed by North State Environmental, restoration entailed excavation of a new and wider flood plain, relocation and elevation of the stream bed, installation of rock and log energy dissipating structures and headwater wetland restoration. The project was co-funded through a Daphne Coastal Impact Assistance Program Grant, MBNEP National Fish and Wildlife Foundation Gulf Environmental Benefits Grant, and a State CWA Section 319 Grant, and is one of the first in Alabama funded with money from settlements related to the Deepwater Horizon oil spill. The purpose of the restoration project was to address the stability of the creek and the upstream wetlands of this reach of Tiawasee Creek. The design proposed to stop the headcutting in the multiple threaded portion of the reach and restore and stabilize the channel through natural channel restoration and best engineering practices. This was met through the design and construction of proper channel dimension, layout and profile based on reference reach data and instream stabilizing structures. The design also mitigated sediment deposition downstream through channel stabilization and native vegetation installation. Finally, the channel and floodplain was designed to support high flows and associated shear stresses that might occur along Tiawasee Creek. GMC’s team provided restoration services including watershed assessment, conceptual design, engineering analysis, hydrologic and hydraulic modeling, construction design, permitting, and cost estimation, in addition to bid document preparation, grant oversight, construction inspection, monitoring pre- and post-implementation and adaptive management services as the project progressed. Construction management/oversight throughout the entire construction period was provided to ensure the as-built conditions were consistent with the project design.
Scope of Services