Little River Flow Study and Water Supply Reservoir

Client: City of Raleigh

Location: Raleigh, NC

Summary: ENTRIX is leading an environmental flow study to assess the potential ecological effects of flow alteration of the Little River as a result of the proposed Little River Water Supply Reservoir for the City of Raleigh in Eastern Wake County, NC. This study is designed to provide a technical basis for evaluating alternative flow release regimes and a basis for negotiation of an acceptable reservoir release scheme as part of the permitting and NEPA compliance processes. The Little River is a morphologically complex and ecologically important river and provides habitat for several federal- and state-listed mussel and fish species including dwarf wedgemussel, Tar spinymussel, green floater, Carolina madtom, Roanoke bass, and Neuse River waterdog.

ENTRIX is leading a Technical Advisory Group (TAG) of resource agency personnel from a variety of state and federal agencies through the study design, implementation, and interpretation phases of the study using contemporary ideologies of comprehensive environmental flow studies. The complexities of this low-gradient, blackwater, and river-wetland system require a study goes beyond the traditional habitat mapping and modeling studies to include analysis of the effects of altered streamflows on interconnected riparian wetlands and water quality. The study will include innovative mesohabitat mapping, water quality and streamflow monitoring, riparian wetland hydrology investigations, development of habitat and biological suitability criteria, hydrodynamic and habitat modeling, water quality modeling, and analysis of connectivity of the river channel with adjacent wetlands.

ENTRIX is performing all technical work on the study including habitat mapping, set-up and monitoring of a water quality and streamflow gauge network, establishment of biological and habitat criteria, hydrodynamic habitat modeling, water quality modeling, and release scenario evaluations.