**3. Study area and data collection**

This research focused on the City of Kelowna located in the Okanagan Valley (British Colum‐ bia, Canada). The City has five water districts including the City of Kelowna District (CKD), Glenmore Ellison Irrigation District (GEID), Black Mountain Irrigation District (BMID), Rutland Water District (RWD), and the South East Kelowna Irrigation District (SEKID). The CKD served as the study area of this research. Using three major pumping stations, the CKD primarily supplies water from the Okanagan Lake. The present study used monthly mean water demand data from 1996 to 2010 (http://www.kelowna.ca/). The population censuses of 1996, 2001, 2006, and 2011, along with the best-fit parabolic equation (with coefficient of determination of *R*<sup>2</sup> ≈ 1) allowed estimation of the population in noncensus years. Weather indices including temperature, wind speed, relative humidity, and rainfall, were drawn from the Environment Canada weather data (http://kelowna.weatherstats.ca/) collected at Station A (latitude 49°57′13″N, longitude 119°22′29″W) located at the City of Kelowna's airport.
