The document provides an overview of sustainable stormwater management and low impact development (LID). It discusses the importance of effective stormwater management given finite freshwater resources. It describes the paradigm shift from conventional stormwater approaches to LID, which aims to maintain pre-development hydrologic functions through decentralized small-scale controls like bioretention and permeable pavements. LID can provide multiple benefits including reduced infrastructure costs, improved water quality and more.

1. Overview of Sustainable Stormwater Management/Low Impact Development Presented by Sandeep Mehrotra Vice President Hazen and Sawyer P.C. www.hazenandsawyer.com Sponsored by

12. Comparison of Pre- and Post-Development Hydrographs, CSP 1992

13. Evolution of Paradigms for Storm Water Management Run it in the Ditches

23. Functional Drainage

24. Conventional Development Centralized Pipe and Pond Control

25. LID Development Conservation Minimization Soil Amendments Open Drainage Rain Gardens Rain Barrels Pollution Prevention Disconnected Decentralized Distributed Multi-functional Water Use Multiple Systems

26. Good Drainage Paradigm The Problem: Conventional Site Design Collect Concentrate Convey Centralized Control

27. Hydrologically Connected Ecologically Dysfunctional

28. Get the water away as fast as possible!

29. Conventional vs. LID Storm Water Approach

30. Lot Level Source Controls LID Site Create a Hydrologically Functional Lot Conservation Open Drainage Rain Gardens Amended Soils Rain Barrel Porous Pavement Narrower Streets

31. Cumulative Beneficial Impacts of LID Techniques LID rebuilds ecological functions piece by piece.

36. “ Rain Gardens”

37. View of Lot with Storage and Bioretention

38. Rain Garden Treatment Train Approach Bioretention Cell Storm Drain System Bioretention Cell Grass Filter Strip Flow Path Grass Swale

39. Large Lot Composite Site Analysis

49. IMP Effect or Function Slow Runoff Filtration Infiltration Retention Detention Evaporation Water Quality Control Soil Amendments X X x Bioretention X X X X X X Vegetated Buffers X X X X Grassed Swales X X X X Rock Swales X X X X Rain Barrels X Street Trees X Vegetated Roofs X X X X Permeable Materials X X X Rock Beds X X X X

50. The Bioretention Concept Original Design P.G County 1993

51. Vegetated Conveyance

59. 2’ 2” Mulch Infiltration System Highly Pervious Soils Existing Ground

60. 2’ 2” Mulch Drain Pipe Filtration System Existing Ground Highly Pervious Soils

61. 2’ 2” Mulch Drain Pipe Combination Filtration / Infiltration Moderately Pervious Soils Gravel Sandy Organic Soil Existing Ground

67. Residential Rain Gardens

68. Example Bioretention Areas

72. Bioretention Construction Costs Excavation (assume no hauling) $3 - $5 / cy Fill Media $15 - $20 / cy Vegetation/ Mulch $1.00 - $1.50 / sf Underdrains /Gravel & Outlet $0.50 - $1.50 / sf Total $10 - $14 / sf

74. Off-line 2005 Lake County, OH

75. Flow-through 2005 lake County, OH

78. Porous Pavers Capturing Roof Runoff

80. Portland Oregon Bureau of Environmental Services Building

81. Street Tree / Shrub Filters

83. Proprietary Devices

84. Typical Layouts - Office Building

85. Typical Layouts - Big Box Design

88. Thank You