Changes

Rainwater harvesting is one simple example of a cost-effective solution which yields multiple benefits. Rainwater harvesting provides an alternative water source for activities that do not require potable water, such as gardening or flushing toilets. In turn, residents use less municipal drinking water – which is expensive and energy intensive to treat and distribute, especially for such activities. For some municipalities, including the City of Toronto, Region of Peel, and City of Guelph, treating and distributing water can account for 25% to 60% of total municipal electricity costs. As such, the One Water approach can provide conservation not only of water, but of energy. This relationship is known as the water-energy nexus. Additionally, capturing rainwater decreases the flow of water to municipal stormwater management systems, which can alleviate stress on older systems that lack capacity for high volumes of water, potentially reducing instances of flooding and erosion. The alleviation of such stresses is akin to finding ‘hidden capacity’ within an existing system, and can result in the deferment of expensive system upgrades if implemented on a broad enough scale. The One Water approach emphasizes solutions that offer multiple benefits. To properly evaluate these solutions, it is helpful to consider water management through the lens of the watershed.

Rainwater harvesting is one simple example of a cost-effective solution which yields multiple benefits. Rainwater harvesting provides an alternative water source for activities that do not require potable water, such as gardening or flushing toilets. In turn, residents use less municipal drinking water – which is expensive and energy intensive to treat and distribute, especially for such activities. For some municipalities, including the City of Toronto, Region of Peel, and City of Guelph, treating and distributing water can account for 25% to 60% of total municipal electricity costs. As such, the One Water approach can provide conservation not only of water, but of energy. This relationship is known as the water-energy nexus. Additionally, capturing rainwater decreases the flow of water to municipal stormwater management systems, which can alleviate stress on older systems that lack capacity for high volumes of water, potentially reducing instances of flooding and erosion. The alleviation of such stresses is akin to finding ‘hidden capacity’ within an existing system, and can result in the deferment of expensive system upgrades if implemented on a broad enough scale. The One Water approach emphasizes solutions that offer multiple benefits. To properly evaluate these solutions, it is helpful to consider water management through the lens of the watershed.

== The Watershed Perspective ==

== The Watershed Perspective ==

As noted in previous section, the watershed scale is an appropriate spatial scale for many water infrastructure and water management decisions, as it is a functional response unit. While working to employ the precepts of the One Water approach within a municipal water planning framework, it is helpful to start with the watershed as a foundational perspective. The watershed perspective reveals the complex, manifold ways in which water systems – natural and built – are connected. Understanding these layers, how they are linked, and how a watershed functions will support cost-effective, holistic municipal water and land management. It will also make clear many types of levels of risk which otherwise may not have been revealed. For example, a rainfall event might lead to contaminated stormwater runoff draining to drinking water supply intake locations. A watershed approach not only encourages the identification of these types of risks, but also makes it easier to determine potential solutions to mitigate problems. Efforts to minimize risk can encourage municipalities to work together on integrated planning and management solutions, since watersheds cross political boundaries.

As noted in previous section, the watershed scale is an appropriate spatial scale for many water infrastructure and water management decisions, as it is a functional response unit. While working to employ the precepts of the One Water approach within a municipal water planning framework, it is helpful to start with the watershed as a foundational perspective. The watershed perspective reveals the complex, manifold ways in which water systems – natural and built – are connected. Understanding these layers, how they are linked, and how a watershed functions will support cost-effective, holistic municipal water and land management. It will also make clear many types of levels of risk which otherwise may not have been revealed. For example, a rainfall event might lead to contaminated stormwater runoff draining to drinking water supply intake locations. A watershed approach not only encourages the identification of these types of risks, but also makes it easier to determine potential solutions to mitigate problems. Efforts to minimize risk can encourage municipalities to work together on integrated planning and management solutions, since watersheds cross political boundaries.