Improving “Salmon Friendly” Flow Compliance in the Okanagan River System

Water supply fluctuations in the Okanagan Valley of British Columbia induce seasonal flood and drought conditions that challenge water managers to satisfy competing, human-system versus natural-system needs. An audit of water management performance from 1982-1997 indicated frequent non-compliance of water regulation decisions with “fish friendly” lake levels and river flows specified by the 1982 Canada-BC Okanagan Basin Agreement (OBA). Development and deployment of an environmental decision support system to provide real-time, fish and water management tools (FWMT) to decision makers offered a means to improve water management decisions simultaneously affecting human systems and natural systems. FWMT provides a risk assessment framework to: integrate biophysical processes, deal with multiple species and locations, anticipate socioeconomic outcomes of water management decisions and increase cooperation among water users to improve fish and water management. Observations from pre-FWMT “control” versus FWMT deployment years (n = 20 and 11, respectively) indicate significant improvements at daily (p < 0.001) and annual (p < 0.05) time scales in water management compliance with OBA guidelines to protect salmon during critical egg-to-fry emergence stages. FWMT-enabled improvements and increased fish production have been achieved without increased damage to water system infrastructure, riparian property or agriculture from flood or drought conditions.