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

7 Project Area – Land Use

8 Project Area Commercial Land Use

9 Project Area School Land Use

10 Project Area Medium Density Res. Land Use

11 Project Area

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

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

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

15 Project Area – Source Area Delineations Source Areas Commercial

Project Area – Source Areas

17 WinSLAMM Modeling Results WinSLAMM Model Comparison of Development Scenarios

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

19 Model Inputs WinSLAMM Road Swale Description:

20 WinSLAMM Model Inputs WinSLAMM Infiltration Basin Description:

21 WinSLAMM Modeling Results WinSLAMM Model Comparison of Development Scenarios

22 WinSLAMM Modeling Results WinSLAMM Model Comparison of Development Scenarios

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

24 Questions / Discussion

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