Water Balance Model: Introducing the Rainwater Harvesting Module
Note to Reader:
On December 3, 2013 the Partnership for Water Sustainability and the Irrigation Industry Association of BC (IIABC) are co-hosting a workshop that will explore regulatory requirements, water balance benefits and practical applications of rainwater harvesting design and operation. The workshop is structured as four cascading modules.
In the second of four modules, the team of Kirk Stinchcombe, Carolyn Drugge and Richard Boase will speak to the benefits of utilizing rainwater as a resource in the urban environment. Below is a preview of the perspective that Richard Boase will provide.
TO REGISTER for the workshop, go to the IIABC website: https://www.irrigationbc.com/irrigation/courses/view_scheduled/119
TO DOWNLOAD a copy of the Program Overview, click on Get Your Mind Into the Gutter: A Workshop on Rainwater Harvesting in British Columbia.
The Plan for the Future
In November 2009, the Water Balance Model Partnership released a blueprint document titled Water Balance Model for Canada – The Plan for the Future.
“The Plan for the Future laid out a road map for greatly increasing both the computational capabilities of the Water Balance Model and its usability in visioning future alternatives for use of water and land. Subsequently, senior government funding enabled development of a number of modules, including the Rainwater Harvesting Module for non-potable water re-use. Canada Mortgage & Housing Corporation (CMHC) have provided funding for this module,” explains Ted van der Gulik, Partnership Chair.
“The Partnership is pleased to announce that the Rainwater Harvesting Module is now functional and will go live as of the Get Your Mind Into the Gutter Workshop on December 3, 2013.”
CMHC Funded Module Development
“The early success of the Water Balance Model in British Columbia generated interest in expanding the focus of the tool to reach a national audience. This culminated in the decision by CMHC in 2004 to fund development of the national portal at www.waterbalance.ca,” continues Cate Soroczan, Senior Researcher.
“CMHC provided financial support to help the Water Balance Model Partnership complete the first phase of a Storage from Re-Use Module. This first phase encompasses a rainwater harvesting and storage component with variable sizing and demand. This capability will allow the user to optimize both the demand for potable water and the size of the physical storage required to achieve a maximum benefit.”
Raising Awareness of the Urban Water Cycle
“The immediate value of the new Rainwater Harvesting Module is in large part educational. Initially, we see the module as providing a way to raise awareness of the urban water cycle and how this understanding could eventually be applied in practice, especially by those who are involved in the design of infrastructure and communities. In the long-term, we see the module supporting strategies that achieve provincial policy goals,” observes Richard Boase, Partnership Co-Chair.
“The Rainwater Harvesting Module enables the Water Balance Model user to explore the beneficial use of rainwater. In other words, rainwater is a resource and therefore should not be viewed as waste. A consideration in developing the module is the Living Water Smart target that 50% of new municipal water needs will be acquired through conservation by 2020. Widespread implementation of rainwater harvesting systems would help BC communities achieve the 50% target.”
“Our approach in evolving the Water Balance Model is holistic. That is why, for example, we emphasize that topsoil is the interface between drought management and drainage management. If land development practices protect the sponge, then communities will use less water for lawn irrigation. Furthermore, less drainage runoff means less potential for stream erosion and hence less impact on stream habitat.”
Modification of QUALHYMO Calculation Engine
“We have extended the QUALHYMO engine and WBM interface so as to enable assessment of domestic non-potable reuse of reusable rainwater as an alternative to discharge as waste. Supporting objectives included incorporation of computational algorithms for both water supply and water demand,” reports Dr. Charles Rowney, the Partnership’s Scientific Authority and the creator of the QUALHYMO engine.
“The user of QUALHYMO will now be able to readily evaluate the potential of re-use as a management alternative in any watershed for which characteristic use parameter information has been developed.”
“Water Balance Model for British Columbia” launched at 2003 Union of BC Municipalities Urban Forum
In 2002, looking at rainfall differently led the Province of British Columbia to adopt the Water Balance Methodology, initiate a performance target approach to capturing rain where it falls, and initiate changes in the ways rainwater runoff is returned to streams. In 2003, an inter-governmental partnership co-chaired by the Province and Environment Canada developed the Water Balance Model, a scenario comparison and decision support tool.
“Provincial direction is ‘mimic the natural Water Balance’ to protect stream and watershed health. The Water Balance Model is a means to an end: ‘think like a watershed’. The tool promotes awareness and action. Our efforts are now bearing fruit. A ‘design with nature’ land ethic is taking hold in many communities,” concludes Ted van der Gulik.
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