2010-2012 Research Projects: Sustainable Coastal Development and Economy
Project: Infiltration versus Retention for Stormwater Quantity and Quality Management: A Continued Assessment of Rainfall Response in Coastal South Carolina Watersheds
Dan Hitchcock, Clemson University
In coastal areas with shallow water tables and low gradient topography, surface and groundwater coupling complicates the feasibility of pre- and post-development flow prediction, including peak flow rates. Groundwater-surface water interactions (pathways and contributions of each during a storm event) are not appropriately considered in the stormwater management practice selection and design process.
Objectives of this continuing project include actions to (1) utilize storm hydrograph separation techniques (surface and groundwater) for data collected from two comparable headwater streams draining coastal watersheds (one is slated for and is partially comprised of existing development, the other has no existing or planned development), (2) compare and contrast groundwater-surface water interactions within and between these two coastal first-order watersheds, both with shallow water tables, but each with differing yet related soil types, (3) characterize the utility of modified SCS curve numbers (CN) within respective watersheds for rainfall-runoff estimates based on previously collected data and compare to other methods currently being developed for low-gradient systems in the lower coastal plain, (4) determine the general feasibility, with respect to water quantity and quality, of enhanced infiltration versus retention and storage based on soil and water interactions, and (5) disseminate project results to regulatory agencies, local county and municipal planning and public works staff, other professional decision-makers, such as developers, engineers, surveyors, and landscape architects, and educators including extension specialists.
Contact for Questions
Dan Hitchcock (email@example.com)
Project: Linking Residential Development and Organic Matter Loading to the Coastal Zone: The Role of Stormwater Ponds as Sources of Bioreactive Organic Carbon and Nitrogen
Erik Smith, University of South Carolina
The prevalence of stormwater wet detention ponds in coastal South Carolina may have significant influences on the biogeochemical linkages between terrestrial nutrient runoff and organic matter production and fate in the coastal zone. That many of these ponds are high in algal biomass suggests that organic matter production within these ponds can be substantial. Quantifying the magnitude and fate of this organic matter is critical to determining the influence of stormwater ponds on coastal water quality impairment. A key issue in this regard is the effects that various land uses and current design criteria for stormwater ponds have on pond Net Ecosystem Production (NEP) and bioavailability of pond-derived organic carbon and nitrogen.
The specific objectives of this study are to (1) quantify rates of NEP across 30 individual residential and golf course stormwater ponds and determine relationship(s) between nutrient conditions and NEP in these ponds, (2) quantify degradation kinetics and bioavailability of pond-derived dissolved organic carbon (DOC) and dissolved organic nitrogen (DON), the extent to which these vary as a function of pond NEP, and the effects that pond-derived DON has on primary productivity and phytoplankton species composition of coastal marine ecosystems, (3) determine the role that stormwater pond size and design attributes have on nutrient – NEP relationship(s) and DOC/DON production and bioavailability, and (4) compare and contrast temporal dynamics of pond productivity, internal nitrogen transformations, and DOC/DON production and bioavailability in response to storm events among a subset of ponds of varying morphometry and design criteria.
Contact for Questions
Erik Smith (firstname.lastname@example.org)