ACHIEVING WATER BALANCE: “To understand the OUT = IN equation in an engineering context, we need to think in terms of a safety margin or factor and what that actually means in practice” added Ron Smith, Ministry of Sustainable Resource Management, when he elaborated on the science-based understanding behind the Water Balance Equation (April 2005)


The “Penticton Workshop” held as an adjunct to the BCWWA Annual Conference in April 2005 was the first regional event organized under the Convening for Action in British Columbia (CFA) umbrella, an element of the Water Sustainability Action Plan for British Columbia, released a year earlier in February 2004.

The workshop was titled “Demand Management Strategies – Achieving Water Balance” – A Workshop on Dealing with Uncertainty and Managing Risk.

This full-day technical transfer session connected the dots between water resource planning, climate variability and risk management; explored the tools and techniques available through demand-side management; and included a case study application to provide participants with ‘hands-on’ planning practice.

Moving Towards a Water Balance Way-of-Thinking

“In the era of the high speed computer, the current generation of water supply planners has for the most part lost sight of this guiding principle: the essence of sound engineering is observation and deduction.  When practitioners wrap layers of pseudo-complexity around a core assumption that may be flawed, solutions to water supply needs can become convoluted and/or unsustainable,” stated Kim Stephens, Program Coordinator, Water Sustainability Action Plan for British Columbia.

“Through outreach and education, an Action Plan goal is to peel back those layers of pseudo-complexity and in so doing re-focus practitioners on basic water management principles and concepts, in particular the water balance way-of-thinking.”


Download a copy of the workshop program: “Demand Management Strategies – Achieving Water Balance” – A Workshop on Dealing with Uncertainty and Managing Risk. Comprehensive in scope, the program identified what participants would learn from each program segment.

Then read a report about the event: Report on Water OUT = Water IN Workshop.

Educational Objectives

Given the foregoing frame-of-reference, insight into the educational objectives in providing knowledge transfer at the Penticton Workshop is provided below.

The Water Balance

“Conventional water supply planning is typically based on a narrow understanding of engineering statistics without really understanding the role that climate variability plays,” noted Robert Hicks, a workshop presenter and a Senior Engineer with the Greater Vancouver Regional District.

“A core message is that the OUT = IN equation is variable on both sides. Something to think about is that in mathematics one cannot solve for two variables with a single equation. In other words, it is time for practitioners to go back to the basics and re-think how we approach water supply analysis and planning.”

Understanding Safety Factors

“To understand the OUT = IN equation in an engineering context, we need to think in terms of a safety margin or factor and what that actually means in practice” added Ron Smith, P.Eng., another workshop presenter and a Sustainable Resource Officer with the Province.

“In a nutshell, when the service population is small and the safety factor is large, climate variability may be inconsequential. As population and water demand grow, however, the safety factor shrinks.”

“Eventually we reach a condition of vulnerability where a small shift in the water balance can trigger a supply crisis. This has been the prevailing pattern for almost 20 years. We have effectively used up the safety factor because we have not understood climate variability.”

Choice of Language

“Given there is a need for change in the way we plan and manage water supply systems, a goal of the WSC is to facilitate a breakthrough in practitioner thinking similar to that which has recently been achieved in the practice of urban drainage,” observed Kim Stephens,

In that case, changing the language from ‘stormwater management’ to ‘rainwater management’ has had a profound influence on how drainage engineers in particular view their world. This has opened their minds to doing things differently, so that the Natural Water Balance will be protected and/or restored, by implementing source control measures that reduce the annual volume of rainwater runoff (created as a result of land development).”

“Building on this successful precedent, the Action Plan objective is to accelerate the mind-shift that will see the water balance way-of-thinking move beyond rainwater management to embrace all components of the water cycle.”

“In British Columbia, school children learn about the hydrologic cycle in Grade Five. By high school they have forgotten about it. There is a parallel pattern in engineering education. The concept is re-taught in first year hydrology and then forgotten after graduation. These observations have provided an impetus for the Action Plan to champion OUT = IN as the way to re-focus water supply planners.”