Low Impact Development in Coastal South Carolina: A Planning and Design Guide

Low Impact Development in Coastal South Carolina: A Planning and Design Guide

ACE Basin & North Inlet-Winyah Bay National Estuarine Research Reserves Network of 28 Reserves NOAA Program Research, Stewardship, Education, Training State Partnership

What is LID? Integrated, comprehensive approach to development Mimics natural hydrologic cycle Infiltration, evaporation, and treatment of runoff Minimize impervious cover Divert runoff from a common collection point

Why LID? Protects and restores coastal resources Mitigates stormwater impacts Increases groundwater recharge Preserves integrity of ecological and biological systems Reduces sewer overflows Minimizes urban heat stress Good business plan Reduces costs Increase marketability Social Educates public Enhances aesthetics

If we can do projects like this

Why do we have so many like this?

Barriers to LID Implementation High/Uncertain cost Maintenance concerns No clear guidelines Lack of education/experience Codes/Ordinances Site constraints

What exactly do users need? Needs Assessment Focus Groups Survey

Information our stakeholders requested Design specifications Case studies/examples Maintenance checklists Cost estimates Performance standards Calculations/Spreadsheet tool Infill/Retrofit recommendations Construction sequences Enforcement tactics Planning processes Education/Outreach materials

How? Funding through the NERRs Science Collaborative Reserve-based Collaboration Applied Science Project Team ACE Basin & NIWB NERRs SC SeaGrant Center for Watershed Protection

Kickoff Workshop: January 16, 2013 Over 60 attendees Planners Engineers Developers Researchers Educators Landscape Architects Public Works

Presentations & Technical Break-Out Sessions Addressed stakeholder input Reviewed stormwater regulations Provided example BMP specifications and spreadsheet tool Described model stormwater ordinances Discussed developing meaningful case studies

LID Research Roundtable: April 16, 2013 How to incorporate current local science 20 researchers, engineers, and regulators

Discussion: Adjustments for designing BMPs Impairments and pollutants of concern Nitrogen, phosphorus, sediment, bacteria Coastal Conditions: Flat topography High/variable groundwater table Tidal amplitude Salinity Poorly-drained soils & confining layer Vector control Higher PET

GOAL: Provide specifications that meet the state standards for volume control while including the latest information on pollutant removal for each BMP

Climate and Stormwater Roundtable: September 20, 2013 24 climate specialists, engineers, and coastal researchers What are the potential impacts of climate change and seal level rise?

Collaborative Review of LID Manual: January 9, 2014 60 engineers, planners, landscape architects, & stormwater professionals Provide feedback on draft Planning strategies Conservation principles Neighborhood site design Technical specifications

Spring/Summer 2014: Editing, Editing, Editing Addressing suggestions from collaborative review Adding more SC coast illustrations Final layout and appearance

Chapter 1: Introduction Introduction What is LID? Need for Coastal SC Guidance Purpose and Application Benefits of LID Environmental & Economic Coastal Features and LID Flat terrain, high water table, altered drainage, soils, pollutants of concern, unique development patters, hurricanes and flooding

Chapter 2: Strategies for Local Governments Applicable regulations and requirements Regional planning strategies Code and ordinance checklists How to incorporate LID into land use regulations Incentives Neighborhood planning considerations PUDs, TDRs, retrofitting, infill, redevelopment Regulatory strategies Site plan review process Coordination Enforcement

Chapter 3: Conservation Principles and Neighborhood Site Design for LID Conservation of Natural Areas Preserve and maintain open space Protect critical resources Promote buffers Reduce impervious cover Neighborhood Site Design Considerations Roadway design Parking guidance LID Landscaping

Bioretention Chapter 4: Guide to Stormwater Best Management Practices Permeable Pavement Systems Stormwater Infiltration Green Roofs Rainwater Harvesting Impervious Surface Disconnection Open Channel Systems Stormwater Filtering Systems Dry Detention Practices Wet Detention Ponds Stormwater Wetlands

Chapter 5: Local Case Studies

Appendices Compliance Calculator Guidance Infiltration Testing Soil Compost Amendment Water Quality Volume Peak Discharge Coordinating Erosion and Sediment Control with LID Planning Maintenance Checklists Adapting Stormwater Management for Climate Change Stormwater Statutes and Regulations

Next Steps Manual available online: www.northinlet.sc.edu/lid/ Printed copies distributed at training: October 28: Conway October 29: Charleston October 30: Hardeeville www.northinlet.sc.edu/training/events.html

Katie Ellis EllisK@dnr.sc.gov 843-953-9845 http://www.dnr.sc.gov/marine/nerr/ctp.html LID Manual Project page: http://www.northinlet.sc.edu/lid/