TESTING POTENTIAL OUTCOMES OF A WETLAND RESTORATION USING A GROUNDWATER MODELING APPROACH

Historically in the U.S., wetlands have been drained or altered for residential, commercial, or agricultural use or for societal reasons. The social, environmental, ecological, and economic benefits of wetland systems are now widely recognized and have led to a rise in wetland conservation, restoration, and creation projects, as well as the adoption of a national no net wetlands loss policy. Despite increased investment in wetland projects, a lack of understanding and empirical testing of best practices in wetland restoration persists. Furthermore, the absence of scientifically vetted methodologies for wetland restoration and insufficient site suitability analyses have led to many failed attempts at reestablishing self-sustaining wetlands.

Here, we quantitatively assess the efficacy of a process-based ecological restoration technique intended to promote functional wetland hydrology, implemented at a retired cranberry bog in Manomet, Massachusetts. This restoration approach involved the creation of microtopography and redistribution and mixing of the shallow substrate with the goal of bringing the water table closer to the surface, increasing soil moisture in the root zone, and increasing habitat variability at the site. We examine the theoretical impact of these techniques on groundwater and soil moisture dynamics with a parametric study using variably saturated groundwater models. Sensitivity analyses will be conducted on parameters including the near surface mixing ratio, geologic connectivity, microtopographic geometry and density, ditch fill material, and groundwater inflow. We examine water table position and soil moisture resulting from different restoration scenarios to inform and optimize future restoration practices.