1. 1 Using WinSLAMM For Stormwater Retrofit in Urban Environments August 22, 2011 StormCon 2011, Anaheim, CA Presented by: James Bachhuber PH Caroline Burger PE AECOM Madison, WI

2. 2 Dense Urban Land Uses Require Stormwater Retrofitting  Open space is very limited  Land values are very high  Treatment measures have higher safety & aesthetic requirements

3. 3 Overview of Santa Monica Stormwater Study Purpose of Study:   Test WinSLAMM approach to stormwater management   Identify priority land uses for pollutant generation   Compare alternative stormwater management for pollution control levels

4. 4 Overview of Santa Monica Stormwater Study Basic Approach:   Identify representative pilot study area   Create WinSLAMM files to represent local conditions Source areas Rainfall Drainage Soils

5. 5 Overview of Santa Monica Stormwater Study Basic Approach (continued):   Model pilot area with no management measures (base condition)   “Retrofit” alternative management practices to predict runoff volume & pollution control achieved

6. 6 Overview of Santa Monica Stormwater Study Stormwater Practices Analyzed:   Street cleaning (vacuum assist)   Porous pavement   Infiltration Pits   Biofilters

7. 7 Project Area – Land Use

8. 8 Project Area Commercial Land Use

9. 9 Project Area School Land Use

10. 10 Project Area Medium Density Res. Land Use

11. 11 Project Area

12. 12 Project Area – Source Area Delineations Source Areas Residential – High Density

13. 13 Project Area – Source Area Delineations Residential – Low Density Source Areas

14. 14 Project Area – Source Area Delineations Source Areas Residential – Single Family

15. 15 Project Area – Source Area Delineations Source Areas Commercial

16. Project Area – Source Areas

17. 17 WinSLAMM Modeling Results WinSLAMM Model Comparison of Development Scenarios

18. 18 WinSLAMM Model Inputs Source Areas in WinSLAMM: Conventional LID Roofs Disconnected Single Sidewalk Narrower Streets

19. 19 Model Inputs WinSLAMM Road Swale Description:

20. 20 WinSLAMM Model Inputs WinSLAMM Infiltration Basin Description:

21. 21 WinSLAMM Modeling Results WinSLAMM Model Comparison of Development Scenarios

22. 22 WinSLAMM Modeling Results WinSLAMM Model Comparison of Development Scenarios

23. 23 WinSLAMM Modeling Results WinSLAMM Model Comparison of Development Scenarios* * Annual loadings from 43.2 acre Cedar Hills development

24. 24 Questions / Discussion

25. 25