Deal Island Drainage Assessment
Somerset County, MD
AMT provided surveying, UAV drone investigations, field assessment, and analysis of the open ditch drainage system on the Deal Island Peninsula as part of a grant funded project in the communities of Dames Quarter and Oriole. The study area included approximately 33,950 LF of roadside ditches and 24,930 LF of non-roadside ditches.
The project was part of the Deal Island Peninsula Project (DIPP) Coastal Resiliency Assessment to identify and assess those areas most vulnerable to ditch flooding. The open ditch assessments were completed under Phase I of the 2019 Green Infrastructure Resiliency Grant which is a multi-phase process that provides an improved inventory of the open ditch drainage system and serves as a basis to help Somerset County develop a long-range maintenance program for improved drainage. Phase II and III builds upon and refines goals to begin implementing drainage improvement recommendations.
Assessments included quantification, identification, categorization, and prioritization of deficiencies. A Categorization and Implementation Matrix was developed to present to Somerset County and Deal Island Peninsula a summary of the assessed drainage conditions; drainage areas; recommended maintenance schedule and improvements; right-of-way impacts and owner responsibility; and environmental permitting issues. High priority areas included sites which required immediate attention and included mitigation concepts and recommended maintenance improvement measures, along with conceptual cost estimates.
Assessments also included evaluation of tidal range inundation and impacts on open ditch maintenance; discussion on potential impacts of sea-level rise on water surface elevations; and adjacent areas. Research included NOAA Sea Level Rise Viewer and Maryland MERLIN On-Line for sea level rise vulnerability. As part of grant funding requirements, AMT explored opportunities to implement green infrastructure measures within the context of drainage improvement measures for the open ditch drainage system. Green Infrastructure measures included investigating potential locations and practical measures (i.e. rain barrels, gravel-pave, submerged gravel wetland, etc.) that might support and provide increased drainage performance and improvement.