Water Withdrawal EA and Inter-Basin Transfer

Client: Charlotte Mecklenburg Utilities

Location: Charlotte, NC

Summary: Charlotte Mecklenburg Utilities (Utilities) retained Cardno ENTRIX to provide basin hydrologic analysis, environmental impact assessment, instream flow assessment, and an Environmental Assessment (EA) document in support of its proposed expanded water withdrawal from the Catawba River (Mountain Island Lake). During this complex project, Cardno ENTRIX worked closely with Utilities, state and federal agencies, and other parties, to scope and conduct a thorough and highly-defensible hydrologic analysis, instream flow assessment and EA that were readily accepted as the basis for the permit application and approval.

Cardno ENTRIX completed extensive technical analyses to support Charlotte?s proposed increase in water withdrawal, including basinwide and interbasin consumptive water-use estimates, CHEOPS basin hydrologic modeling, reservoir operation and downstream flow impacts modeling, instream flow and aquatic habitat assessment, aquatic resource characterization and mussel survey, and cumulative impact analysis. Cardno ENTRIX performed a consumptive water use analysis for the entire Catawba River basin, covering over 15 counties in North and South Carolina. Working closely with the participants, Cardno ENTRIX modeled the potential impacts of future water withdrawals including the cumulative impacts of consumptive water uses. This impact assessment demonstrated that the proposed withdrawal would have minimal impacts, even under drought conditions.

During the process, the U.S. Fish and Wildlife Service (FWS) identified the potential for the occurrence of and possible impacts to the federally-endangered Carolina heelsplitter (Lasmigona decorata). Cardno ENTRIX promptly worked with the FWS, Duke Energy, and other participants to design and conduct a survey which demonstrated that Carolina heelsplitter was not present in the affected reach of the Catawba River. Cardno ENTRIX also completed informal consultation with the FWS under the Endangered Species Act. These analyses resulted in approval of Charlotte?s proposed water withdrawal increase.