1. Low Impact Development Training Design Exercise Presented by: The Low Impact Development Center, Inc. A non-profit water resources and sustainable design organization www.lowimpactdevelopment.org

2. Copyright 2009 Low Impact Development Center, Inc. Application of Concepts New and Redevelopment New VA and MD SWM Concepts EISA Requirements Objectives

3. Copyright 2009 Low Impact Development Center, Inc.

4. Redevelopment Replace Parking Lot Correct poor drainage around building Improve pedestrian circulation

5. Copyright 2009 Low Impact Development Center, Inc. Redevelopment Program development goals SWM requirements and objectives Identify critical resource areas Opportunities and Constraints Retrofit strategies Retrofit techniques Identify Benefits

6. Copyright 2009 Low Impact Development Center, Inc. New Development Construct new office with similar footprint Connect circulation with existing site Identify potential environmental issues

7. Copyright 2009 Low Impact Development Center, Inc. LID UFC Process Define Planning Goals Perform Site Evaluation Develop LID Strategies Prepare LID Concept Design Target O & M Strategy

8. Copyright 2009 Low Impact Development Center, Inc. % Imperviousness (assume 65%) Rainfall Depth/ESD Runoff Depth QE = PE*Rv 0r ~1.24” Post Cn > Pre and PE>1 inch so calc Cpv Approx 0.4 inch depth over surface so if 30 acres then 4,500 cf Virginia Key Points

9. Copyright 2009 Low Impact Development Center, Inc. Maryland Key Points Redevelopment (Assume 40% imperviousness): Reduce Impervious area by 50% or, ESD/LID for wq for 50% or, ESD and reduction for 50% OR On-site structural or, Off-site structural for 50% or, Or Combination OR Retrofit off-site Stream restoration Trading Planning AND… Implement ESD for NET INCREASE in impervious areas

10. Copyright 2009 Low Impact Development Center, Inc. EISA 438: Norfolk 95 Th Percentile 1.63 Inches

11. Copyright 2009 Low Impact Development Center, Inc. UFC Tools LID Manual NRCS Charts 95th Percentile Charts

12. Copyright 2009 Low Impact Development Center, Inc.