Changes

The first option may be suitable for systems optimized for exterior irrigation only. But regulatory authorities may not permit the use of such seasonal systems as part of a storm water control strategy. Year round systems can be protected from freezing by locating the pipes, pumps and cistern indoors and/or below the frost penetration depth[http://www.raqsb.mto.gov.on.ca/techpubs/ops.nsf/0/ee1f1756eacc00e18525808200628fbf/$FILE/OPSD3090.101%20Rev%231%20Nov2010.pdf].

The first option may be suitable for systems optimized for exterior irrigation only. But regulatory authorities may not permit the use of such seasonal systems as part of a storm water control strategy. Year round systems can be protected from freezing by locating the pipes, pumps and cistern indoors and/or below the frost penetration depth[http://www.raqsb.mto.gov.on.ca/techpubs/ops.nsf/0/ee1f1756eacc00e18525808200628fbf/$FILE/OPSD3090.101%20Rev%231%20Nov2010.pdf].

<br>

<br>

==Inspection and Maintenance==

==Inspection and Maintenance==

[[File:RAINWATER HARVESTING TANK 550x550.jpg|thumb|Large cistern being installed underground]]

[[File:RAINWATER HARVESTING TANK 550x550.jpg|thumb|Large cistern being installed underground]]

[[File:RWH Tree.PNG|thumb|Conceptual image of an underground cistern being used for irrigation of nearby vegetation on site.]]

[[File:RWH Tree.PNG|thumb|Conceptual image of an underground cistern being used for irrigation of nearby vegetation on site.]]

Adequately sizing rainwater harvesting systems is critical to optimizing their operation because under-sizing results in systems that are unable to provide sufficient, reliable sources of water while oversizing increases the capital costs incurred and poses potential water quality risks if stored water remains unused for long periods of time. In a recent research literature review, Semaan et al. (2020) identified sizing for water storage as most important for system optimization, yet found that sizing for cost is a more frequently implemented optimization approach. They note several sizing and optimization approaches and tools are available globally. <ref>Semaan, M., Day, S.D., Garvin, M., Ramakrishnan, N., Pearce, A. 2020. Optimal sizing of rainwater harvesting systems for domestic water usages: A systematic literature review. Resources, Conservation & Recycling: X 6 (2020) 100033. https://www.sciencedirect.com/science/article/pii/S2590289X20300049?via%3Dihub </ref>     

 

In a recent international research literature review on urban rainwater harvesting systems, Campisano et al. (2017) note that degree of implementation and design choices are strongly influenced by economic constraints (need for low cost, easy to retrofit systems) and government regulations (need for policies, standards and guidelines that ensure system efficacy and improve community acceptance), and that systems tend to be designed for water conservation alone, without considering co-benefits like helping to achieve stormwater management objectives. <ref> Campisano, A., Butler, D., Ward, S., Burns, M.J., Friedler, E., DeBusk, K., Fisher-Jeffes, L.N., Ghisi, E., Rahman, A., Furumai, H., Han, M. 2017. Urban rainwater harvesting systems: Research, implementation and future perspectives. Water Research. 115 (2017) 195-209. https://www.sciencedirect.com/science/article/abs/pii/S0043135417301483?via%3Dihub </ref>  Adequately sizing rainwater harvesting systems is critical to optimizing their operation because under-sizing results in systems that are unable to provide sufficient, reliable sources of water while oversizing increases the capital costs incurred and poses potential water quality risks if stored water remains unused for long periods of time. In a recent research literature review, Semaan et al. (2020) identified sizing for water storage as most important for system optimization, yet found that sizing for cost is a more frequently implemented optimization approach. They note several sizing and optimization approaches and tools are available globally. <ref>Semaan, M., Day, S.D., Garvin, M., Ramakrishnan, N., Pearce, A. 2020. Optimal sizing of rainwater harvesting systems for domestic water usages: A systematic literature review. Resources, Conservation & Recycling: X 6 (2020) 100033. https://www.sciencedirect.com/science/article/pii/S2590289X20300049?via%3Dihub </ref>     

   

   

Follow the link below for detailed guidance on approaches to sizing rainwater harvesting systems in Ontario. <br>

Follow the link below for detailed guidance on approaches to sizing rainwater harvesting systems in Ontario. <br>

<h3>Water Quantity</h3>

<h3>Water Quantity</h3>

In theory a large enough RWH cistern could retain 100% of a single storm. However, sizing a stormwater cistern must account for regulatory requirements, available space, budget, and draw-down i.e. rate of use. If a RWH system is being employed for storm water control, the cistern size will typically be greater than that for optimized potable water use reduction.<br>

In theory a large enough RWH cistern could retain 100% of a single storm. However, sizing a stormwater cistern must account for regulatory requirements, available space, budget, and draw-down i.e. rate of use. If a RWH system is being employed for storm water control, the cistern size will typically be greater than that for optimized potable water use reduction.<br>

In 2007-2010 STEP monitored and modelled three rainwater harvesting systems in the Greater Toronto Area[http://www.sustainabletechnologies.ca/wp/home/urban-runoff-green-infrastructure/low-impact-development/rainwater-harvesting/performance-evaluation-of-rainwater-harvesting-systems-toronto-ontario/]. Each system was sized  to balance stormwater management objectives with with potable water use reduction for irrigation and toilet flushing. Around 18-20% of the precipitation was lost directly from the rooftop, and the annual stormwater capture varied between 18 and 42%.

In 2007-2010 STEP monitored and modelled three rainwater harvesting systems in the Greater Toronto Area[http://www.sustainabletechnologies.ca/wp/home/urban-runoff-green-infrastructure/low-impact-development/rainwater-harvesting/performance-evaluation-of-rainwater-harvesting-systems-toronto-ontario/]. Each system was sized  to balance stormwater management objectives with with potable water use reduction for irrigation and toilet flushing. Around 18-20% of the precipitation was lost directly from the rooftop, and the annual stormwater capture varied between 18 and 42%.

<h3>Water Quality</h3>

<h3>Water Quality</h3>

{{:Rainwater_harvesting:_Water_quality}}

{{:Rainwater_harvesting:_Water_quality}}

==Incentives and Credits==

==Incentives and Credits==

*[[Rain Barrels|Rain Barrels]]

*[[Rain Barrels|Rain Barrels]]

==External Links==

==External Links==

===Rainwater Harvesting System design guides===

===Rainwater harvesting system design guides===

*[https://www.csagroup.org/store Canadian Standards Association (CSA) B805-18/ICC805-2018, Rainwater harvesting systems]

*[https://www.csagroup.org/store Canadian Standards Association (CSA) B805-18/ICC805-2018, Rainwater harvesting systems]

*[https://www.crd.bc.ca/docs/default-source/water-pdf/cmhcrainwaterhandbook.pdf?sfvrsn=67aa96c9_2 CMHC Guidelines for Residential Rainwater Harvesting Systems Handbook (2012)]

*[https://www.crd.bc.ca/docs/default-source/water-pdf/cmhcrainwaterhandbook.pdf?sfvrsn=67aa96c9_2 CMHC Guidelines for Residential Rainwater Harvesting Systems Handbook (2012)]

===Organizations===

===Organizations===

*[http://www.harvesth2o.com/about.shtml HarvestH2O]

*[http://www.harvesth2o.com/about.shtml HarvestH2O]

===Proprietary systems===  

===Proprietary systems===  

*[http://greyter.com/ Greyter]

*[http://greyter.com/ Greyter]

*[http://www.interpump.ca/ Interpump]

*[http://www.interpump.ca/ Interpump]

*[http://rh2o.com/company RH₂O]

*[http://rh2o.com/company RH₂O]

==References==

==References==