Moving Beyond the Damage Report: Adapting to Climate Change in the Okanagan Region Stewart Cohen Adaptation & Impacts Research Division (AIRD) Environment Canada, Dept. of Forest Resources Management, UBC Presented at Canadian Columbia River Forum, October 27-28, 2008.

Today’s discussion—Okanagan water resources and climate change The climate change “damage report” Water supply Agricultural and residential water demand Change in risk Assessment of adaptation options Group-based modelling Results from OSWRM Looking ahead

Okanagan region, British Columbia, is part of the Columbia Basin Okanagan Basin CANADA U.S.A. Source: Cohen and Kulkarni (2001); left panel from Alan Hamlet (U. Washington) Zosel Dam

Supply depends on storage in upland reservoirs mainstem lakes ground water (limited) Okanagan Basin – snowmelt watershed with semi-arid climate Photos: upper left—Kelowna and Okanagan Lake, lower left-- Osoyoos and Osoyoos Lake (Denise Neilsen); right— installation of intake at Penticton, Okanagan Lake (Bob Hrasko)

Water Resources in the Okanagan Basin Area = 8200 km 2 Okanagan Valley = 160 km in length Population: 2006 = 340,000 [2001 = 300,000] Governance; 13 municipalities, 3 regional districts, 4 First Nation communities, 59 “improvement districts” Agriculture: fruit, vineyards, pasture; 40% irrigated lands

Agricultural land use in the Okanagan Basin (photos from Denise Neilsen)

The 2003 Okanagan drought & fire Responding to future climate change & population growth?

Okanagan Study Teams ( ) Stewart Cohen (P.I.) – Adaptation & Impacts Research Division-EC, Institute for Resources Environment & Sustainability-UBC, Vancouver Denise Neilsen (P.I ), Scott Smith (P.I ), Grace Frank, Walter Koch – Pacific Agricultural Research Centre-AAFC, Summerland Younes Alila, Wendy Merritt* – Forest Resources Management, UBC (*now at Australian National University) Mark Barton, Roger McNeill, Bill Taylor, Dave Hutchinson, Wendy Avis – Pacific & Yukon Region-EC Tina Neale, Philippa Shepherd, James Tansey, Jeff Carmichael, Stacy Langsdale, Rachel Welbourn, Natasha Schorb, Jennifer Ardiel, Glen Hearns, Alex Russell, Aviva Savelson, Sharon Bennett, Charlie Wilson – IRES & SCARP, UBC Brian Symonds, B.C. MOE, Penticton Bob Hrasko, Agua Consulting, Kelowna. Barbara Lence, Civil Engineering, UBC Craig Forster, U. Utah Allyson Beall, Washington State University Thanks to Andrew Reeder, RDOS (formerly City of Summerland); Toby Pike, Water Supply Association; Greg Armour, OBWB; Patrick Deakin, Town of Oliver; Phil Epp, BC MOE; Jillian Tamblyn, Okanagan Nations Alliance; Leah Hartley, RDCO; Peter Waterman, BC Fruit Growers Assoc. & City of Summerland; & many others. Supported by grants from the CCAF/CCIAP (#A206, A463/433, A846), Natural Resources Canada, Ottawa. Study team ( ) & invited guests at team meeting, Summerland, June 2002

Streamflow Scenarios for Vaseux Creek (Merritt et al., 2006)

Local defined drought – 30% average annual flow Risks associated with water supply and demand in response to climate change (Neilsen et al., 2004) Maximum allowable demand – 2002 use

Incorporation of climate change into Trepanier Landscape Unit Water Management Plan –Recommends demand management as first priority, along with supply augmentation, by 2050 if no climate change assumed, and by 2020 if climate change is assumed Impact on Okanagan Water Management

Moving Beyond The Damage Report an opportunity for participatory integrated assessment (PIA) & decision support…. += Decision Support Model Technical Info & Data Experience Based Knowledge & Values

Preliminary sketch of decision model (Langsdale et al., 2006, 2007)

Input from some participants at Okanagan study model building workshop, April 2005 (Cohen & Neale, 2007)

Upland agriculture supply / demand balance, high population growth; 1= base case; 2= : HadCM3-A2 NOTE: Supply Demand Balance = (supply – demand) / demand

Uplands residential indoor supply / demand balance, high population growth, no climate change 1= base case; 2= = = with HadCM3- A2

: Upland agriculture supply / demand balance, high population growth, 1= HadCM3-A2; 2= HadCM3-A2 with DSM and densification

Okanagan Inflows vs. Water Demands, HadCM3-A2 (source: Langsdale et al., 2006; in Cohen and Neale 2006) AVERAGE YEAR DRY YEAR Note: assumes no change in instream demands to support ecosystems, and reduction in agricultural demand in dry years

: Upland agriculture supply / demand balance, high population growth; 1= HadCM3-A2 2= HadCM3-A2 with unlimited supplemental use of Okanagan Lake NOTE: Assumes withdrawals from lake is unlimited

Okanagan Lake stage, high population growth, no climate change 1= base case; 2= = = , with HadCM3-A2

: Okanagan Lake stage, high population growth, unlimited supplement with Okanagan Lake, no DSM, max agr.-res. allocations, min conservation flows 1= no climate change 2= HadCM3-A2 3= CGCM2-B2 4= CSIROMk2-B2 NOTE: Assumes withdrawals not limited by shortages otherwise apparent when relying on tributaries

: Uplands instream allocation deficit, high population growth, 1= HadCM3-A2 2= HadCM3-A2 plus unlimited supplement with Okanagan Lake

: Upland agriculture supply / demand balance, high population growth; 1= base case; 2= HadCM3-A2 3= HadCM3-A2 with DSM and densification 4= HadCM3-A2 with DSM and Okanagan Lake 5= Hadley A2 with unlimited use of Okanagan Lake only

: Okanagan Lake stage, high population growth; 1= base case; 2= HadCM3-A2 3= HadCM3-A2 with DSM (includes densification) 4= HadCM3-A2 with DSM and Okanagan Lake 5= HadCM3-A2 with Okanagan Lake only

Okanagan adaptation costs, based on recent & proposed water projects (source: McNeill & Hrasko, 2006) GW = groundwater Watershed = supply expansion WT = water treatment Conserv. = manage demand

Conclusions and Looking Ahead In the Okanagan, climate change will result in reduced water supply, increased water demand, and a regional water deficit that would increase over time These effects are greater than what would be projected from population growth alone Years with water supply shortages would occur more frequently DSM combined with supplemental use of valley bottom lakes would offer the region a viable adaptation portfolio, but this would be challenging to manage within the regional context of rapid population growth There needs to be more explicit inclusion of climate change adaptation in long term sustainable development planning for the Okanagan and the larger Columbia Basin Participatory integration offers an important opportunity for shared learning and ownership of research outcomes, so that global climate science and local water policy can be more easily linked Can link to research and planning initiatives originating from within the region Could inform future model development and improvement (e.g. OSWRM— land use change, groundwater, managing instream allocations) Can link to ongoing planning related to balancing watershed management objectives

For more information on Okanagan studies… [navigate to Projects Completed; project report listed as Cohen and Neale, 2006; additional papers by Langsdale et al., The Integrated Assessment Journal, and Langsdale et al. in review; OSWRM available for download] This project was made possible by financial support from the Government of Canada’s Climate Change Impacts and Adaptation Program, Projects A206, A463/433, and A846, and by in-kind support from federal, provincial and local government agencies, non-government organizations, and the University of British Columbia. We thank Craig Forster, Allyson Beall, and Jeff Carmichael for assistance with model construction.