Rainwater harvesting in Canada

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A small rainwater harvesting tank in Quebec. Maison solaire ecoologique, ile Sainte-Helene 12.JPG
A small rainwater harvesting tank in Quebec.

Rainwater harvesting is becoming a procedure that many Canadians are incorporating into their daily lives, although data does not give exact figures for implementation. [1] Rainwater can be used for a number of purposes including stormwater reduction, irrigation, laundry and portable toilets. [2] In addition to low costs, rainwater harvesting is useful for landscape irrigation. Many Canadians have started implementing rainwater harvesting systems for use in stormwater reduction, irrigation, laundry, and lavatory plumbing. Provincial and municipal legislation is in place for regulating the rights and uses for captured rainwater. Substantial reform to Canadian law since the mid-2000s has increased the use of this technology in agricultural, industrial, and residential use, but ambiguity remains amongst legislation in many provinces. Bylaws and local municipal codes often regulate rainwater harvesting.

Contents

Multiple organizations and companies have developed in Canada to provide education, technology, and installation for rainwater harvesting. These include the Canadian Association for Rainwater Management (CANARM), [3] Canadian Mortgage and Housing Corporation (CMHC), and CleanFlo Water Technologies. [4] CANARM is an association that prioritizes education, training and spreading awareness for those entering the rainwater harvesting industry. [3]

Property rights

The National Plumbing Code permits the collection of rainwater for non-potable uses such as toilet flushing and outdoor irrigation throughout Canada. [5] The right to harvest and use rainwater is determined by the provincial government and municipal bylaws. [5] However, a majority of the provinces lack any significant legislation. The law of capture is not well defined and it varies for residential and non-domestic uses. When building a rainwater storage system, it is required that the design follows closely to the provincial codes and municipal bylaws. [2] Multiple publications and reports have been developed by the Canadian Mortgage and Housing Corporation (CMHC) in order to aid Canadians in designing and installing rainwater capture systems that comply with these codes, regulations and bylaws.

Provincial property rights

Many provinces have outlined little to no provincial property rights pertaining to rainwater. Listed below are the provinces with some provincial legislation. However, many local municipalities have bylaws outlining criteria for capture and storage containers among other articles related to rainwater harvesting.

Alberta

Alberta has a set of Rainwater Harvesting Guidelines for residential use. They are recommended for the safe design, construction and maintenance of residential rainwater harvesting systems. The guidelines provide additional detail than what is present in the current code and supports conformance to CAN/CSA 128.1 Design and Installation of Non-Potable Water Systems/Maintenance and Field Testing of Non-Potable Water Systems. The Alberta Building Code and the National Plumbing Code requirements have precedence over these guidelines. In addition to the guidelines, a handbook was developed to provide broader understanding of the technical components of the guidelines. [6]

British Columbia

The Victoria BC Marriott green roof. Victoria BC Marriott green roof.jpg
The Victoria BC Marriott green roof.

Rainwater in British Columbia appears to be common property subject to the law of capture. Effectively, rainwater belongs to no one and everyone until it is captured. While landowners do not have a property interest in water until it is captured, their right to harvest rainwater is unrestricted and not subject to concerns of downstream water users. Rainwater is not included in the Water Act's system of prior allocation. The likely common law position does not recognize correlative rights of other users to share equitably in the common resource of rainwater. [2]

Ontario

In Ontario, the province permits the use of rainwater for flushing toilets and urinals, as well as for sub-surface and below ground irrigation systems. [7] A large number of standards and regulations have been put in place regarding catchments, conveyance networks, and storage containers in Ontario Guidelines for Residential Rainwater Harvesting Systems. [7] Since the temperature during winter months in Ontario drops below zero, rainwater is at a high risk of freezing. Therefore, the province of Ontario places a strong significance on guidelines to ensure that rainwater is in a controlled temperature environment. In addition, to avoid freezing in the pipe network, the water must be properly controlled via draining and temperature controls. [7] Various systems and scenarios have been outlined regarding overflow management, pressurization, and back-flow prevention. [7]

Applications of rainwater harvesting in Canada

Agriculture

A rainwater harvesting pool for irrigation and water for livestock. Rainwater Harvesting and Plastic Pond 3.JPG
A rainwater harvesting pool for irrigation and water for livestock.

In Canada, rainwater harvesting used as a means of irrigation is not popular among farmers. Because of a rise in ecofarming, many farmers have implemented these systems. The uses for the rainwater harvested for agriculture includes irrigation and water for livestock. Often the water collected is redirected to a deep pit with percolation.

Leadership in Energy and Environmental Design (LEED)

Leadership in Energy and Environmental Design (LEED) is a rating system that is recognized as the international mark of excellence for green building in 150 countries. This includes Canada as recognized by the Canada Green Building Council. They give points for obtaining certifications to buildings with rainwater harvesting technologies implemented. These credits include the following: Stormwater quantity and quality controls to reduce runoff, increase reuse, and stop pollutants; efficient landscaping for rainwater reuse; innovative wastewater technologies for non-potable applications such as toilet flushing and process water; water efficiency to reduce the burden on municipal water supply and wastewater systems; and recycled content for use in rainwater harvesting materials. [8]

Industry

The Centre for Interactive Research on Sustainability uses rainwater capture methods, which helped it to become the first LEED Platinum building at the University of British Columbia. CIRS Building UBC.jpg
The Centre for Interactive Research on Sustainability uses rainwater capture methods, which helped it to become the first LEED Platinum building at the University of British Columbia.

Similar to agriculture, rainwater harvesting in Canada for industrial purposes is not widely used. If rainwater is utilized for industrial or commercial uses, a large cistern is generally implemented. These cisterns can hold up to 40,000 litres of water. [9] In the Greater Toronto Area where the temperature in the winter months reaches well below freezing, cisterns are placed in temperature controlled areas such as an underground parking lot or a basement. [9] The Centre for Interactive Research on Sustainability at the University of British Columbia (UBC) makes use of various rainwater capture methods for plumbing, heating and cooling. Data is not available on the number of buildings or businesses implementing rainwater harvesting.

Residential

Rainwater harvesting for residential use can be achieved easily by placing a tank underneath a downspout outside the home. [1] There is also use in green roofs for irrigating plants naturally, providing a cooling system, and regulating condensation. In Canada, the regulations and legislation are still being developed for rainwater harvesting and greywater reuse (water used for laundry, showers and sinks [1] ).

Potential impacts and benefits

The main source of water in the region is from mountain runoff, such as the Okanagan Mountain.

Impacts

In areas where water is scarce, rainwater harvesting can reduce the consumption of groundwater and in turn can be used to recharge the groundwater. [2] In the summer months of Canada, the practice can decrease the pressure on municipal systems and is therefore seen as a great "green" alternative for water supply. [10]

In Canada, rainwater harvesting has the potential to impact environmental flows and downstream water users. The hydrological cycle contains surface water, groundwater and rainwater. The effects on the hydrological cycle would be significant if rainwater became an advantageous solution to water quality and availability. [2] However, the effects this practice has on a watershed is still unknown and further research must be conducted.

Saskatoon's wastewater treatment plant. City of Saskatoon's wastewater treatment plant.jpg
Saskatoon's wastewater treatment plant.

While the majority of the country has not yet faced water scarcity issues, it is believed that the potential for this to happen will increase because of climate change. [2] However, one example of these issues is the Okanagan region in British Columbia. Currently, 89.5% of the surface water being used as a source is constrained because of licensing restrictions. [2] Because of low volumes of rainfall throughout the year, an increase in rainwater harvesting could cause less water to be available to license holders that are downstream. [2]

Benefits

Rainwater harvesting can limit the disruption of natural hydrology by reducing impervious cover, increasing on-site infiltration, reducing or eliminating pollution from stormwater runoff and eliminating contaminants. [8] Furthermore, it can reduce the use of potable water or other natural surface/subsurface water resources available near sites for landscape irrigation. Rainwater harvesting also results in a reduction of wastewater generation and potable water demand. In addition, it reduces the burden on municipal water supply and wastewater systems. [8]

See also

Related Research Articles

<span class="mw-page-title-main">Plumbing</span> Systems for conveying fluids

Plumbing is any system that conveys fluids for a wide range of applications. Plumbing uses pipes, valves, plumbing fixtures, tanks, and other apparatuses to convey fluids. Heating and cooling (HVAC), waste removal, and potable water delivery are among the most common uses for plumbing, but it is not limited to these applications. The word derives from the Latin for lead, plumbum, as the first effective pipes used in the Roman era were lead pipes.

<span class="mw-page-title-main">Greywater</span> Type of wastewater generated in households without toilet wastewater

Greywater refers to domestic wastewater generated in households or office buildings from streams without fecal contamination, i.e., all streams except for the wastewater from toilets. Sources of greywater include sinks, showers, baths, washing machines or dishwashers. As greywater contains fewer pathogens than blackwater, it is generally safer to handle and easier to treat and reuse onsite for toilet flushing, landscape or crop irrigation, and other non-potable uses. Greywater may still have some pathogen content from laundering soiled clothing or cleaning the anal area in the shower or bath.

<span class="mw-page-title-main">Storm drain</span> Infrastructure for draining excess rain and ground water from impervious surfaces

A storm drain, storm sewer, surface water drain/sewer, or stormwater drain is infrastructure designed to drain excess rain and ground water from impervious surfaces such as paved streets, car parks, parking lots, footpaths, sidewalks, and roofs. Storm drains vary in design from small residential dry wells to large municipal systems.

<span class="mw-page-title-main">Water conservation</span> Policies for sustainable development of water use

Water conservation includes all the policies, strategies and activities to sustainably manage the natural resource of fresh water, to protect the hydrosphere, and to meet the current and future human demand. Population, household size and growth and affluence all affect how much water is used. Factors such as climate change have increased pressures on natural water resources especially in manufacturing and agricultural irrigation. Many countries have already implemented policies aimed at water conservation, with much success. The key activities to conserve water are as follows: any beneficial reduction in water loss, use and waste of resources, avoiding any damage to water quality; and improving water management practices that reduce the use or enhance the beneficial use of water. Technology solutions exist for households, commercial and agricultural applications. Water conservation programs involved in social solutions are typically initiated at the local level, by either municipal water utilities or regional governments.

<span class="mw-page-title-main">San Francisco Public Utilities Commission</span> American local government agency

The San Francisco Public Utilities Commission (SFPUC) is a public agency of the City and County of San Francisco that provides water, wastewater, and electric power services to the city and an additional 1.9 million customers within three San Francisco Bay Area counties.

<span class="mw-page-title-main">Reclaimed water</span> Converting wastewater into water that can be reused for other purposes

Water reclamation is the process of converting municipal wastewater (sewage) or industrial wastewater into water that can be reused for a variety of purposes. Types of reuse include: urban reuse, agricultural reuse (irrigation), environmental reuse, industrial reuse, planned potable reuse, and de facto wastewater reuse. For example, reuse may include irrigation of gardens and agricultural fields or replenishing surface water and groundwater. Reused water may also be directed toward fulfilling certain needs in residences, businesses, and industry, and could even be treated to reach drinking water standards. The injection of reclaimed water into the water supply distribution system is known as direct potable reuse. However, drinking reclaimed water is not a typical practice. Treated municipal wastewater reuse for irrigation is a long-established practice, especially in arid countries. Reusing wastewater as part of sustainable water management allows water to remain as an alternative water source for human activities. This can reduce scarcity and alleviate pressures on groundwater and other natural water bodies.

<span class="mw-page-title-main">Rainwater harvesting</span> Accumulation of rainwater for reuse

Rainwater harvesting (RWH) is the collection and storage of rain, rather than allowing it to run off. Rainwater is collected from a roof-like surface and redirected to a tank, cistern, deep pit, aquifer, or a reservoir with percolation, so that it seeps down and restores the ground water. Dew and fog can also be collected with nets or other tools. Rainwater harvesting differs from stormwater harvesting as the runoff is typically collected from roofs and other surfaces for storage and subsequent reuse. Its uses include watering gardens, livestock, irrigation, domestic use with proper treatment, and domestic heating. The harvested water can also be committed to longer-term storage or groundwater recharge.

<span class="mw-page-title-main">Canada Mortgage and Housing Corporation</span> Canadian national housing agency

Canada Mortgage and Housing Corporation is Canada's federal crown corporation responsible for administering the National Housing Act, with the mandate to improve housing by living conditions in the country.

<span class="mw-page-title-main">Combined sewer</span> Sewage collection system of pipes and tunnels designed to also collect surface runoff

A combined sewer is a type of gravity sewer with a system of pipes, tunnels, pump stations etc. to transport sewage and urban runoff together to a sewage treatment plant or disposal site. This means that during rain events, the sewage gets diluted, resulting in higher flowrates at the treatment site. Uncontaminated stormwater simply dilutes sewage, but runoff may dissolve or suspend virtually anything it contacts on roofs, streets, and storage yards. As rainfall travels over roofs and the ground, it may pick up various contaminants including soil particles and other sediment, heavy metals, organic compounds, animal waste, and oil and grease. Combined sewers may also receive dry weather drainage from landscape irrigation, construction dewatering, and washing buildings and sidewalks.

<span class="mw-page-title-main">First flush</span> Initial surface runoff of a rainstorm

First flush is the initial surface runoff of a rainstorm. During this phase, water pollution entering storm drains in areas with high proportions of impervious surfaces is typically more concentrated compared to the remainder of the storm. Consequently, these high concentrations of urban runoff result in high levels of pollutants discharged from storm sewers to surface waters.

<span class="mw-page-title-main">Rainwater tank</span>

A rainwater tank is a water tank used to collect and store rain water runoff, typically from rooftops via pipes. Rainwater tanks are devices for collecting and maintaining harvested rain. A rainwater catchment or collection system can yield 2,358 litres (623 US gal) of water from 2.54 cm (1.00 in) of rain on a 92.9 m2 (1,000 sq ft) roof.

<span class="mw-page-title-main">Urban runoff</span> Surface runoff of water caused by urbanization

Urban runoff is surface runoff of rainwater, landscape irrigation, and car washing created by urbanization. Impervious surfaces are constructed during land development. During rain, storms, and other precipitation events, these surfaces, along with rooftops, carry polluted stormwater to storm drains, instead of allowing the water to percolate through soil. This causes lowering of the water table and flooding since the amount of water that remains on the surface is greater. Most municipal storm sewer systems discharge untreated stormwater to streams, rivers, and bays. This excess water can also make its way into people's properties through basement backups and seepage through building wall and floors.

Water supply and sanitation in Jordan is characterized by severe water scarcity, which has been exacerbated by forced immigration as a result of the 1948 Arab–Israeli War, the Six-Day War in 1967, the Gulf War of 1990, the Iraq War of 2003 and the Syrian Civil War since 2011. Jordan is considered one of the ten most water scarce countries in the world. High population growth, the depletion of groundwater reserves and the impacts of climate change are likely to aggravate the situation in the future.

<span class="mw-page-title-main">Stormwater harvesting</span>

Stormwater harvesting or Stormwater reuse is the collection, accumulation, treatment or purification, and storage of stormwater for its eventual reuse. While rainwater harvesting collects precipitation primarily from rooftops, stormwater harvesting deals with collection of runoff from creeks, gullies, ephemeral streams, underground conveyances. It can also include catchment areas from developed surfaces, such as roads or parking lots, or other urban environments such as parks, gardens and playing fields.

<span class="mw-page-title-main">Water-sensitive urban design</span> Integrated approach to urban water cycle

Water-sensitive urban design (WSUD) is a land planning and engineering design approach which integrates the urban water cycle, including stormwater, groundwater, and wastewater management and water supply, into urban design to minimise environmental degradation and improve aesthetic and recreational appeal. WSUD is a term used in the Middle East and Australia and is similar to low-impact development (LID), a term used in the United States; and Sustainable Drainage System (SuDS), a term used in the United Kingdom.

<span class="mw-page-title-main">Centre for Interactive Research on Sustainability</span> Offices, Lecture Hall in Canada, Canada

The Centre for Interactive Research on Sustainability (CIRS) is located at the University of British Columbia's (UBC) Point Grey Campus in Vancouver. The building is dedicated to research collaboration and outreach on urban sustainability. It was officially opened in November 2011.

<span class="mw-page-title-main">Low-impact development (U.S. and Canada)</span>

Low-impact development (LID) is a term used in Canada and the United States to describe a land planning and engineering design approach to manage stormwater runoff as part of green infrastructure. LID emphasizes conservation and use of on-site natural features to protect water quality. This approach implements engineered small-scale hydrologic controls to replicate the pre-development hydrologic regime of watersheds through infiltrating, filtering, storing, evaporating, and detaining runoff close to its source. Green infrastructure investments are one approach that often yields multiple benefits and builds city resilience.

A runoff footprint is the total surface runoff that a site produces over the course of a year. According to the United States Environmental Protection Agency (EPA) stormwater is "rainwater and melted snow that runs off streets, lawns, and other sites". Urbanized areas with high concentrations of impervious surfaces like buildings, roads, and driveways produce large volumes of runoff which can lead to flooding, sewer overflows, and poor water quality. Since soil in urban areas can be compacted and have a low infiltration rate, the surface runoff estimated in a runoff footprint is not just from impervious surfaces, but also pervious areas including yards. The total runoff is a measure of the site’s contribution to stormwater issues in an area, especially in urban areas with sewer overflows. Completing a runoff footprint for a site allows a property owner to understand what areas on his or her site are producing the most runoff and what scenarios of stormwater green solutions like rain barrels and rain gardens are most effective in mitigating this runoff and its costs to the community.

Sewer mining is a concept where municipal wastewater (sewage) is pumped from a trunk sewer and treated on-site to accommodate a range of local, nonpotable water needs. It is a strategy for combating water scarcity. It combines decentralized wastewater management and water reclamation. Since 2012, it is used as a tool for improving water management and promoting reuse of water in Australia.

Rainwater management is a series of countermeasures to reduce runoff volume and improve water quality by replicating the natural hydrology and water balance of a site, with consideration of rainwater harvesting, urban flood management and rainwater runoff pollution control.

References

  1. 1 2 3 Collecting and Using Rainwater at Home. Canadian Housing and Mortgage Corporation. 2013.
  2. 1 2 3 4 5 6 7 8 Duke, Katie (2014). "Ownership of Rainwater and the Legality of Rainwater Harvesting in British Columbia". Appeal. Retrieved 2016-03-29.
  3. 1 2 "CANARM.org - Canadian Association for Rainwater Management". www.canarm.org. Retrieved 2016-03-22.
  4. "Homepage - Water, Septic Tanks and Rainwater Harvesting Systems Canada - Clean-Flo Rainwater Management". Water, Septic Tanks and Rainwater Harvesting Systems Canada - Clean-Flo Rainwater Management. Retrieved 2016-03-22.
  5. 1 2 "Rainwater Harvesting | CMHC". CMHC. Archived from the original on 2018-04-18. Retrieved 2016-02-02.
  6. "Alberta Guidelines for Residential Rainwater Harvesting Systems" (PDF).
  7. 1 2 3 4 Despins, Christopher. "Ontario Guidelines for Residential Rainwater Harvesting Systems" (PDF). Rainwater Harvesting Task Group. Archived from the original (PDF) on 2012-10-30. Retrieved 2016-03-29.
  8. 1 2 3 Resources, Rainwater. "LEED points for Rainwater Harvesting". Rainwater Resources. Archived from the original on 2017-08-12. Retrieved 2016-03-22.
  9. 1 2 "Low Impact Development Stormwater Management Planning and Design Guide - Credit Valley Conservation". Credit Valley Conservation. Retrieved 2016-03-29.
  10. Rinkesh (10 June 2013). "The Advantages and Disadvantages of Rainwater Harvesting". Conservative Energy Future. Retrieved 2016-03-29.