BCWWA – Managing Water Demands in a Growing Community

Antigone Dixon-Warren – Township of Langley and Sibylle Naf – Dayton and Knight presented the issues facing the Township of Langley regarding water supply sources and demand management.

Langley is the most eastern of the Metro Vancouver Municipalities, located in a fertile river valley. – 75% of the land area is in the Agricultural Land Reserve. 100,000 residents.
50% of the water is from groundwater sources from 17 production wells, which is extremely cost effective

Growing Community – 6% of the community is metered – not residential.
Average 475 l/c/d – low for Metro Vancouver – high for Canada.

GVWD is looking at doubling water rates in the next 8 years, with peak season rates an addition 30% compared to off-peak rates.

What steps has Langley Taken to Reduce the Water Demand?

Water Resources Management Strategy – 2002

  • Studies
  • Public Education
  • Policies

Water Management Plan – 2006

  • Part 4 of the Water Act
  • Collaborative Effort
  • Protect Groundwater quality and quantity
  • Legally Enforceable and binding

Water Demand Management Strategy – 2007
Study undertaken by Dayton and Knight looked at the two water sources (GVWD and groundwater) and price structures for each against the increasing population and the opportunities to reduce the water demand through measures.

Residential Water Metering – Cost Benefit Analysis (15 years)
– Costs

  • Capital Cost of installation
  • Annual O&M (meter reading etc)

– Benefits

  • Water Savings
  • Deferred capital projects
  • Wastewater treatment

Cost Benefit Ratio 0.5 to 2.7. Varies based on the inherent assumptions. (If greater than 1 cannot be justified on financial implications alone).

A “realistic target” of 15% water savings. Achievable through:

  • Education/Water Audits
  • Rebate Programs (very popular through township) Clotheswasher rebate favourable cost-benefit)
  • Metering and Pricing (Implementing a Metering Study for residential to confirm cost – benefit)
  • Zone Metering and Intelligent Pressure Management
  • Irrigation, Landscaping
  • Industrial, Commercial, Institutional
  • Bylaws

Is 15% enough? Considering that groundwater is not appropriately managed, Langley is moving forward with the Water Managment Plan, and sees 15% as an achievable target. Only time will tell.

Published by Mike Thomas

Mike Thomas P.Eng. ENV SP, is the author of UrbanWorkbench.com and Director of Engineering at the City of Revelstoke in the Interior of British Columbia, Canada.