The Future of Cost-Benefit and Co-Benefit Tools for Stormwater and Integrated Planning

Transcription

1 The Future of Cost-Benefit and Co-Benefit Tools for Stormwater and Integrated Planning Heather Fisher, AICP, Tetra Tech Kevin Boyer, PE, City of Raleigh Stormwater Management Division Do I need a tool for that? 2 1

2 Green Infrastructure GI What does it cost? How will I benefit? 3 Bringing together complex information Water quality Hydrology Cost estimates Other benefits TBL/co-benefits social, economic, environmental 4 2

3 Data Results Input Output 5 Cost Estimate Reliability Bioretention costs can vary $20-$100/SF depending on setting, site conditions, etc. 6 3

4 Work Plan for Advancing Green Infrastructure and Low Impact Development in Raleigh Cost- Benefit Tool Factsheets O&M Review/ Options Code Review/ Revisions 7 Stakeholder-Driven Process Reviewed Existing Tools Researched Co-Benefits Developed Tool Concept Evaluated how tool would be used Implementation Work Group provided input during each phase. 8 4

5 What tools are already out there? 9 Available Tools Tool Name Cost Nutrients Hydrology Sediment Ecological /Other Benefits Storm-EZ X X Jordan Nutrient Loading Accounting Tool X X Upper Neuse Site Evaluation Tool (SET) X X X X SUSTAIN X X X X WERF BMP Cost Tools X CNT s Green Values Calculator X X X NRDC Calculator X X X X USDA i-tree Software Suite X 5

6 Storm EZ Nutrient Loading Accounting Tool CNT s Green Values Calculators 6

7 Conclusions for Raleigh Cost-Benefit Tool Excel spreadsheet-based (or mobile app option) Ability to interact with the Storm-EZ and the Nutrient Loading Accounting Tool Co-Benefits Literature Review 7

8 Definition of the Triple Bottom Line Framework that identifies environmental, economic, and social benefits Environmental Sustainable Solutions Economic Social TBL Benefits Selected Water Quality Green Jobs and Reducing the Social Cost of Poverty Property Value Benefits of Green Space Reduced Infrastructure Costs Reduced Energy Use and Heat Island Effect Carbon Sequestration Improved Air Quality Flood Mitigation Habitat Mental Health Reduced Crime/Improved Public Safety 8

9 Increased Property Value Radius Approach 9

10 Literature Review Urban and suburban Tree Planting, GI/LID with Vegetation, or Community Gardens Cities similar in population to Raleigh Results Percent increase ranged from 0.7 to 11% (8 studies) Distance ranged from 328 to 4000 ft Could assume 4 to 6% as midpoint UNC study in Wake County: 2% property value increase within 1500 ft of public open space $42 annually in county property taxes per house 10

11 Infrastructure Costs Examples Center for Watershed Protection (1998): C&G 2-3 times as costly as grass swales EPA NC RTP Campus (2001): saved $500,000 using grass swales, water quality ponds, and bioretention (in lieu of C&G and oil&grit separators) City of Seattle (2008): natural drainage reduced costs 24-45% 11

12 Great for block parties! Energy, Climate, and Air Data on benefits of trees used in GI-LID related to shade Savings on cooling and heating costs Carbon sequestration reduced social cost of carbon Improved air quality reduced respiratory health impacts and other externalities 12

13 i-tree Design itree Demonstration Four 6-inch DBH White Oak Saplings One tree on each side of piedmont NC house 20-year period Energy savings: $1000 Carbon: $250 Air quality: $50 13

14 Input for Co-Benefit Calculations Reduced Energy Use, Carbon Sequestration, Air Quality Deciduous Trees Evergreen Trees BMP # planted # preserved # planted # preserved BMP #1 BMP #2 BMP #3 BMP #4 BMP #5 BMP #6 BMP #7 BMP #8 BMP #9 BMP #10 Basic Tool Design 14

15 Basic Design Basic Design 15

16 Tool Next Steps How will the City use the tool? Promote use to developers Public stormwater design cost-benefit analysis Tool for implementing potential future incentives 16

17 Tool Development Formation of a technical committee Peer-reviewed cost data Plan for training of City staff Designation of tool administrator Planning for data updates and maintenance Other Upcoming Tools 17

18 City of Los Angeles: Multiple Benefits of SW Capital Projects MS Access Project Database Tool Data output loaded to Online Viewer

19 37 City of Santa Maria Integrated Plan Decision Tool 38 19

20 City of Santa Maria Integrated Plan Decision Tool 39 City of Santa Maria Integrated Plan Decision Tool 40 20

21 EPA Stormwater Calculator Cost Estimates