This document summarizes an approach to exploring water sustainability issues in island communities through community engagement and systems modeling. It involves identifying key issues through discussion with community members, mapping groundwater vulnerability, and developing an interactive systems dynamics model to explore water usage and availability over time under different policy scenarios. The approach has been applied successfully in two Gulf Islands communities in British Columbia to integrate scientific knowledge into policymaking.

1. Exploring Issues of Water Sustainability in Island Communities 1 University of British Columbia, Lanarc Consultants Ltd. 2 University of Utah 3 Natural Resources Canada Brett Korteling 1 Craig Forster 2 Sonia Talwar 3 Murray Journeay 3

7. Seasonal Island Dynamics Sources: Environment Canada and B.C. Ferries Summertime population increases by 60% to 100% Season of low water availability

10. Contributors Islands Trust - Island Communities Natural Resources Canada BC Water Land Air Protection Environment Canada BC Ferries Malaspina University College BCGWA - CWRA Identify Issues

11. Intrinsic Groundwater Vulnerability DRASTIC-Fm Framework DRASTIC-Fm Mapping South Gulf Islands Conventional DRASTIC methodology modified for fractured rock systems

13. Marine Island System Sea Floor Sea Level Groundwater Flow to Sea Streamflow to Sea Precipitation Evapotranspiration Agricultural Land Concentrated Community Distributed Community

14. Feedback Loops Personal Business Policy Decisions Water Balance Balance = Total Water Wanted – Total Water Available Total Water Wanted Total Water Available - +

15. Total Island Households Annual Household Water Use Net Change # Households Annual Agriculture Water Use Annual ‘ Other’ Water Use Per Hectare Agriculture Water Use Per Household Household Water Use Agriculture Area (Ha) Surface Runoff Precipitation Groundwater Recharge Aquifer Water Table Elevation Business Decision Policy Decision Policy Decision Total Water Use Aquifer Water Volume Total Water Use Total Water Available + - What can we do differently - naturally? Annual Precipitation Evapo- transpiration Policy Decision Personal Choice Policy Decision Personal Choice Captured Surface Runoff Policy Decision Well Pumping Policy Decision Personal Choice Policy Decision Personal Choice Business Decision Climate Total Water Available + + Septic Returns Groundwater Recharge Policy Decision + + + + + - + - + - + + - + + Agriculture Returns Groundwater Recharge Policy Decision Business Decision + + + + + - + - + + - + ‘ Other’ Returns Groundwater Recharge + Availability Minus Use - + -

16. Integrated Comprehensive Water Management Take less, reuse and mimic the natural system

17. Model Interface How do you save a failing system?

18. Sample Explorations What are the critical thresholds?

19. Sustainable Water Yield When are new water practices essential? 4 2 0 1 9 8 0 1 9 9 0 2 0 0 0 2 0 1 0 2 0 2 0 2 0 3 0 A n n u a l W a t e r F l o w s ( 1 0 6 m 3 p e r y e a r ) W a t e r W a n t e d A c t u a l W e l l P r o d u c t i o n A c t i v e A q u i f e r V o l u m e W a t e r U s e d R u n o f f C a p t u r e d 1 0 A c t i v e A q u i f e r V o l u m e ( % o f M a x i m u m ) 0 5 0 0 Water Deficit

23. Acknowledgements