Efficacy of whole-watershed stream restoration for hydrologic retention, nitrogen, and suspended solids in a Piedmont urban forest watershed

Doctoral Candidate Name: 
Destini N. Petitt
Infrastructure and Environmental Systems

The quality and quantity of water in degraded watersheds (i.e.: watersheds undergoing changing land-use, urbanization, agricultural use) may be impaired compared to undisturbed forested watersheds. To enhance the ecosystem function of impaired watersheds, restoration projects have been implemented on a variety of land-use types and at a variety of spatial scales. The 6km2 Reedy Creek urban forested watershed located in Charlotte, North Carolina, has undergone extensive, whole-watershed stream restoration to offset ecosystem degradation caused by historical agricultural use and urban development within the watershed. Streams within the Reedy Creek watershed exhibited channel straightening, disconnection with surrounding floodplains, channel widening, channel incision, and reduced groundwater retention.

This dissertation explores three research topics with the aim of understanding the efficacy of using restoration to reestablish ecological and hydrological functioning within the watershed. I investigated: 1) if whole-watershed stream restoration was successful at increasing recharge to the thick unsaturated zone and ultimately raising groundwater levels by increasing the elevation of stream channels; 2) if the whole-watershed stream restoration approach used in the Reedy Creek watershed in which stream channel morphology and characteristics were altered has changed N retention and seasonal flux; and 3) whether stream restoration has influenced TSS flux within the watershed at both baseflow and stormflow. Findings indicate that 1) restoration was successful at increasing groundwater levels and groundwater retention throughout the watershed; 2) that restoration was successful at decreasing growing season N flux but lead to an increase in N flux during the dormant season; and 3) that restoration was successful at reducing TSS flux at both baseflow and stormflow.

Defense Date and Time: 
Tuesday, July 19, 2022 - 10:00am
Defense Location: 
McEniry 201
Committee Chair's Name: 
Dr. David S. Vinson
Committee Members: 
Dr, Sandra Clinton, Dr. Craig Allan, Dr. Sean Collins, Dr. Rice-Boayue