Stormwater Management and Drainage Manual for the Lake Maumelle Drainage Basin Pulaski County, Arkansas Pulaski County Planning & Development June 2010 Pulaski County Pulaski County Stormwater Management and Drainage Manual Acknowledgements This Manual was developed by Tetra Tech, Inc., under contract to Pulaski County Public Works. Jonathan Smith and John Kosco led development of the Manual, with assistance from Garrett Budd, Scott Job, and Christy Williams (Tetra Tech) and Greg Hoffmann and Cecilia Lane (Center for Watershed Protection). The direction and guidance of Van McClendon (Pulaski County Planning & Development), Sherman Smith (Pulaski County Public Works) and Martin Maner and Jonathan Long (Central Arkansas Water) are greatly appreciated. In addition, the County would like to thank the individuals who took the time to comment on the Public Review Draft of the Manual, including Kathy Wells, Bruno Krisch, Hayes Lenhart, Ben Urbonas, Ian Paton, and Tim Daters. June 2010 ii Pulaski County Stormwater Management and Drainage Manual Contents Acknowledgements .....................................................................................................................................ii Executive Summary .................................................................................................................................... v Part 1: Erosion and Sediment Control BMPs .......................................................................................... 7 1.1 Introduction ...................................................................................................................................... 7 1.2 Regulatory Considerations ............................................................................................................. 10 1.3 Developing a Construction Activity Pollution Prevention Plan..................................................... 13 1.4 Technical specifications for BMPs................................................................................................. 16 A. SITE PREPARATION .................................................................................................................... 18 Land Grading .................................................................................................................................19 Stabilized Construction Exit ..........................................................................................................21 Temporary Diversion (Berm or Ditch) ..........................................................................................23 Topsoil Stockpiling........................................................................................................................25 B. SOIL STABILIZATION ................................................................................................................. 27 Temporary Seeding........................................................................................................................28 Permanent Seeding.........................................................................................................................30 Mulching........................................................................................................................................32 Sodding ..........................................................................................................................................35 Dust Control...................................................................................................................................38 C. SLOPE PROTECTION ................................................................................................................... 40 Silt Fence .......................................................................................................................................41 Brush, Rock, and Other Sediment Barriers....................................................................................44 Erosion Control Blankets and Turf Reinforcement Mats ..............................................................46 Temporary Slope Drains................................................................................................................49 Gabion Baskets and Mattresses .....................................................................................................51 Cellular Confinement Systems ......................................................................................................54 D. DRAINAGE SYSTEM CONTROLS ............................................................................................. 57 Curb Inlet Sediment Barrier...........................................................................................................58 Drop Inlet Sediment Barrier...........................................................................................................61 Culvert Inlet Sediment Barrier.......................................................................................................63 Culvert Outlet Energy Dissipator...................................................................................................64 Rock-Lined Ditches and Channels.................................................................................................67 Grass-Lined Ditches and Channels................................................................................................69 Check Dams for Ditches and Channels..........................................................................................72 E. SEDIMENT TRAPS AND BASINS ............................................................................................... 74 Temporary Sediment (Silt) Traps ..................................................................................................75 Sediment (Detention) Basins .........................................................................................................78 Dewatering Devices.......................................................................................................................82 F. STREAM AND WETLAND PROTECTION ................................................................................. 84 Buffer Zones ..................................................................................................................................85 Vegetated Filter Strips ...................................................................................................................87 Temporary Stream Crossing ..........................................................................................................89 Bioengineering: Live Staking ........................................................................................................91 Wattles (Live Fascines)..................................................................................................................93 Brushlayering.................................................................................................................................96 June 2010 iii Pulaski County Stormwater Management and Drainage Manual G. GOOD HOUSEKEEPING AND OTHER RUNOFF CONTROLS................................................ 98 Material Delivery, Storage, and Use..............................................................................................99 Spill Prevention and Control........................................................................................................100 Vehicle and Equipment Maintenance ..........................................................................................102 Debris and Trash Management ....................................................................................................103 Hazardous Waste Management....................................................................................................105 Concrete Waste Management ......................................................................................................107 Sanitary Facilities ........................................................................................................................109 Employee Training.......................................................................................................................110 Part 2: Stormwater Management BMPs .............................................................................................. 111 2.1 Introduction.................................................................................................................................. 111 2.2 Requirements ............................................................................................................................... 113 2.3 Stormwater Management Approaches and BMP selection.......................................................... 115 2.4 Stormwater BMP Standards......................................................................................................... 120 Bioretention .................................................................................................................................121 Grass Swale..................................................................................................................................127 Permeable Pavement....................................................................................................................132 Virginia DCR Stormwater Design Specifications. No. 7: Permeable Pavement. Virginia Department of Conservation and Recreation, Richmond,