• Climate Change Impacts, Small Water Utility’s Bulk Water Supply, and the Community’s Response

  • Project Components:
    Planning, Conference Presentation, Water Supply
Climate Change Impacts, Small Water Utility’s Bulk Water Supply, and the Community’s Response
2017 BCWWA Conference

KWL's Craig Sutherland and Meghan McKee of North Salt Spring Waterworks District made a presentation on meeting future water supply demands in the face climate change.


The North Salt Spring Waterworks District (NSSWD) relies on St. Mary and Maxwell Lakes to supply potable water for about 5,500 customers on Salt Spring Island, Recent dry summers and increased demand have resulted in extremely low water levels in both lakes, raising concerns about whether available watershed yield and storage is sufficient to support the community’s water demands.  Compounding this concern is projected increased demand coupled with climate change projections of warmer summers and prolonged dry periods.

A hydrological assessment of the two watersheds was completed to assess whether water yield and storage at St. Mary and Maxwell Lakes can support demands up to water licensed withdrawal limit.  To determine the water system’s vulnerability to projected climate change under future 2050s climate conditions, a GIS-based monthly water balance model was developed to produce estimates of monthly water availability for both current and future climate conditions.

The results of these studies indicate that both lakes may able to support current water demands up to 10 -year return period drought (occurring in about 10% of years). However, current storage at St. Mary may be insufficient to support increased demand up to the licensed withdrawal limit and both lakes may not have sufficient storage under future climate change projections. These studies   had given the NSSWD the information it needs to develop a strategy to manage these critical water resources sustainability in the short and long term. In particular, these studies provided the information needed to prepare for and respond successfully to the 2015 drought and work towards reconciling the available supply with development planned within NSSWD boundaries.

Presentation (application/pdf, 4.191Mb)