GIS Data: 2024 Shoreline Management Model - Northumberland County

In 2011, the Virginia General Assembly adopted a policy into law that specifies living shorelines as the preferred management practice for erosion control in Virginia waters. The Center for Coastal Resources Management (CCRM) at the Virginia Institute of Marine Science (VIMS) has been developing tools for many years to guide local governments in shoreline management. In particular, they have focused on the use of ecologically preferred alternatives for erosion control and have conducted research into refining the appropriate uses for a large suite of possible treatments based on existing shoreline conditions. A series of Decision Trees were developed to determine shoreline best management practices (BMPs) when conducting onsite inspections. These were developed to support integrated guidance at the management and regulatory level. This body of work has been expanded and re-developed as a GIS spatial model known as the Shoreline Management Model (SMM) to determine appropriate shoreline BMPs from the desktop using available spatial data and the decision tree logic. The assessment is conducted at a parcel level scale, but the output represents a reach-based or cumulative approach to shoreline management.\nIn 2023, CCRM began an update of the SMM. Version 6.0 continues to use fetch, nearshore bathymetry, bank height, marsh presence, beach presence, presence of submerged aquatic vegetation (SAV), roads and permanent structures within the riparian zone, and existing shoreline erosion control structures. To enhance the model’s capabilities for evaluating best management practices and determining where erosion control practices may impact ecologically sensitive areas, version 6.0 adds wave energy, federal navigation channels, presence of RTE species via predicted suitable habitat, bank slope, and narrow creeks.\nMost appropriate for desktop reviews, regulatory compliance, and comprehensive planning, the recommendations derived from the SMM may be altered due to lot size, shoreline length along a single parcel, proximity of primary buildings to the shoreline, type of existing erosion control structures, land use practices, and local biota\nThe SMM v.6.0 also includes a module that identifies suitable areas for oyster structure placement, which can provide erosion control and habitat enhancement benefits.