“Over the past decade, the City of Kelowna has implemented innovative approaches to management of water use and landscape irrigation, such as the QWEL program. Therefore, it was a natural fit for the Partnership and City to collaborate in the development of the BC Landscape Water Calculator,” states Ted van der Gulik, President, Partnership for Water Sustainability in BC.

“A platform re-build for the BC Agriculture Water Calculator was the opportunity to spin-off the BC Landscape Water Calculator as a stand-alone tool for use by local governments and their residents. At the same time, the City of Kelowna was implementing a landscape bylaw that established an allowable water budget at the individual property scale.”

When he retired from government in 2014, Ted van der Gulik was the Senior Engineer in the BC Ministry of Agriculture. He had a leadership role in provincial initiatives related to water use and management.

Three decades ago he had a vision for a science-based approach to management of water demand in British Columbia. In June 2008, the stars aligned when the provincial government released Living Water Smart, British Columbia’s Water Plan. This was a defining moment in BC’s water history.

Living Water Smart provided the policy framework for a new era of water management in BC. Living Water Smart was a catalyst for action because it established 45 actions and targets for doing business differently, preparing communities for change, and choosing to be water smart.

Ted van der Gulik had a mandate  that allowed him to put his ideas into practice through province-wide implementation of the Agriculture Water Demand Model program. Through a partnership agreement between the Province and the Partnership for Water Sustainability, he has a continuing management responsibility for ongoing program delivery.

Currently, he is responsible for overseeing delivery of  the spin-off suite of online calculators.

“The City of Kelowna has an oversight system in place to ensure that landscape design and irrigation design work together to achieve water efficiency. The City’s approval process is keyed to three requirements:

“The Irrigation Industry Association of BC also became a project partner. The significance of IIABC involvement is that IIABC provides training for landscape irrigation designers and contractors. These trained individuals help support implementation of the City’s QWEL program.

“We also involved the Okanagan Xeriscape Association as a technical resource. OXA assisted with development of a database of nursery plants that are water efficient, drought resistant, and suitable for Okanagan conditions. Currently, this database is only connected to the landscape calculator for use in Kelowna. Basic plant information is used for the rest of the province.”

BC Landscape Water Calculator is Science-Based

“The tool educates users because they are able to compare water use for separate landscape profiles. By following the Users Guide, and through experimentation with the dropdowns, they learn that ‘water need’ varies depending on plant type, irrigation system, local climate and soil type.”

“Most importantly, the tool allows the users to divide their properties into ‘hydrozones’, otherwise known as planting areas. Then they can test various combinations of plant types and irrigation systems. The objective is to be at or below the allowable water budget.

“The power of the tool is that it is linked to the provincial database for the Agricultural Water Demand Model, in particular the 500 metre gridded climate cells. This is what establishes the allowable water budget. It is a real number based on climate data averaged from 2000 through 2010.

“Customizing of the tool for use within Kelowna included plant selection dropdowns developed with assistance from the Okanagan Xeriscape Association. This led us to go the next step and take into account whether there is sun exposure or shade. The database also provides the user with guidance as to whether plant selections are suitable for sun exposure or shade. Think about why that is important.”

“In summary, a key takeaway message is that the BC Landscape Water Calculator has benefited from a major provincial investment in a science-based approach to quantifying how much water is needed for irrigation.

“Now any property owner in BC can zoom in to their property and quantify their outdoor water need based on climate, soil, plant type and irrigation system. We believe this is quite likely the first application of this kind in the world. Over time, province-wide use of the tool would result in enhanced resiliency of community water supplies.”

To Learn More:

“In the coming months, the Partnership for Water Sustainability will proceed with an outreach program. An early priority is to raise awareness of the BC Landscape Water Calculator as a ‘made in BC’ tool for water resiliency planning and regulation of outdoor water use. This announcement is a first step.

“Our vision is that province-wide mainstreaming would begin in 2021. In the meantime, we invite expressions of interest from local governments wishing to be part of the program. Contact us at partnership@watersustainabilitybc.ca.

“While anyone in British Columbia can now use the calculator, there are benefits to a local government in becoming a partner in the program. As the City of Kelowna experience foreshadows, incorporating local knowledge and requirements would stimulate local uptake of the tool.”

“At some point in the foreseeable future, the Partnership envisions there will be an opportunity to interlink the BC Landscape Water Calculator and the Water Balance Model Express for Homeowners.

“The latter is a wet-weather tool for rainwater capture and protection of stream health. Like Lego, homeowners can add building blocks to test how to infiltrate rainwater runoff on their property, and thus reduce discharge to municipal drainage systems.

“The commonality is soil and how soil functions as an absorbent sponge to hold and slowly release water, thereby maintaining the water balance during wet and dry cycles. Once the tools are interlinked, it would be within our grasp to achieve whole-system, water balance management at the property scale.”

Click on the image below to test drive the BC Landscape Water Calculator: