Slow, Sink and Spread Rainwater Runoff: Enhanced capabilities of "Cowichan Water Balance Express for Landowners" showcased by CVRD's Jeff Moore at meeting of Regional Services Committee in November 2015
Cowichan Region is an Incubator for Water Balance Approaches
Over the past decade, the Cowichan Region has experienced a number of floods and droughts. These teachable moments have heightened local awareness of the need to look at rainfall differently and ‘design with nature’ – that is, if communities are to adapt to a changing climate (wetter, warmer winters; longer, drier summers).
Manage Rain Where It Falls
The Cowichan Valley Regional District (CVRD) is a provincial demonstration region for applying the Water Balance Methodology. At the April 2014 meeting of the Regional Services Committee, (former) Ladysmith Mayor Rob Hutchins moved the motion that:
“The Water Balance Web Tool and supporting documents be shared with the CVRD and partner municipal planning staff; and further, that planning staff consider integrating the tool into the planning framework to support watershed management objectives at the Official Community Plan level and Development Permit level.”
In November 2015, Jeff Moore (Environmental Analyst / Technician with the Cowichan Valley Regional District) provided the CVRD Regional Services Committee with an update on development of the online Water Balance Express for Landowners.
Application of Water Balance Methodology
Protection of watershed and stream health ultimately involves maintaining the natural proportion of rainwater entering streams via three pathways: surface flow, interflow (shallow sub-surface flow), and groundwater flow.
The Water Balance Methodology examines the flow paths of water in the watershed, and the flow in streams. To replicate natural processes, it is necessary to establish performance targets that define how to ‘slow, sink and spread’ rainwater.
These performance targets are used to populate the Water Balance Express for Landowners. The tool integrates and balances the three watershed-based performance targets established by partner local governments to mimic the Natural Water Balance.
To Learn More:
Click on the link to download the Primer on the Water Balance Methodology for Protecting Watershed Health.
Slow It. Sink It. Spread It
“Through membership in the Partnership for Water Sustainability since 2007, the CVRD has benefited from access to information, tools and resources for maintaining and improving watershed health within the region. One such tool, the Water Balance Model Express for Landowners was introduced to this Committee in May of 2013,” wrote Jeff Moore in his report to the committee.
“The tool has now been upgraded to utilize a Google map base making it more accessible to the general public while maintaining the engineering and analytical engine in the background to determine pre- and post-development runoff and impacts on watershed health.”
Test Landscape-based Solutions
“The Cowichan WBM Express tool has been available online since April 2014,” continued Jeff Moore. “This web-based tool allows homeowners or developers to quickly size and test landscape-based solutions, such as rain gardens, infiltration swales, or cisterns, to slow, sink, and spread the rainwater falling on their property, thereby helping to restore the natural balance of the region’s water.”
“Starting with an undeveloped property, one can test out different sizes and designs of buildings, landscaping features, and rainwater slow-release features to see the impact of development illustrated by the stream health dial. Alternatively, a homeowner could use the tool to see what features could be added to a property to restore the stream health to a more natural level.”
Express is on a WordPress / Google Platform
“A limitation of the first version of the WBM Express tool was the resolution of the map provided for users to select the watershed in which their property was located.”
“The Environmental Services Division has been working with the Partnership for Water Sustainability to prepare an updated version of the WBM Express tool which uses Google Maps to allow users to zoom in to find their property or even search by civic address to determine the watershed in which their property lies.” explained Jeff Moore.
“Additionally, the improved resolution allows for different targets for rainwater storage and infiltration based on the zoning of each property within the watershed.”
“The new version of the WBM Express tool is on a WordPress/Google platform and will be launched in the coming weeks. It will serve as an even more useful tool for helping maintain the water balance in the Cowichan Region,” concluded Jeff Moore.
To Learn More:
To view the presentation by Jeff Moore, follow these steps or just go directly to Step #4:
- Begin by clicking on www.cvrd.bc.ca
- Select Agendas / Minutes / Videos
- Select Regional Services Committee – video
- Select November 25, 2015
To download a copy of the Staff Report, click on Report to Regional Services Committee on Cowichan Water Balance Model.
To download a PDF copy of the PowerPoint presentation by Jeff Moore, click on Cowichan Water Balance Express.