Changes

[[File:Overground RHW.jpg|thumb|An above-ground cistern. This system is not frost proof, and would have to be drained and closed during winter.]]

[[File:Overground RHW.jpg|thumb|An above-ground cistern. This system is not frost proof, and would have to be drained and closed during winter.]]

[[File: Agc1.png|thumb|An above-ground cistern used for sub-surface irrigation. A filter box is included on the roof drain, no further treatment is shown. The overflow is connected to an underground infiltration area.]]

[[File: Agc1.png|thumb|An above-ground cistern used for sub-surface irrigation. A filter box is included on the roof drain, no further treatment is shown. The overflow is connected to an underground infiltration area.]]

<h3>Place in the Treatment Train</h3>

===Place in the Treatment Train===

To maximize the volume of water available for reuse, a RWH system is usually located near to the front of a treatment train. i.e. Upstream of other LID technologies. The most common exception would be where a site strategy employs a [[Green Roofs|green roof]].  

To maximize the volume of water available for reuse, a RWH system is usually located near to the front of a treatment train. i.e. Upstream of other LID technologies. The most common exception would be where a site strategy employs a [[Green Roofs|green roof]].  

A simple warm-weather system may capture all of the rooftop runoff in an external tank above grade and use it for sub-surface irrigation. In this scenario the tank can overflow via gravity to a sub-surface [[Infiltration chambers|infiltration chamber]] or a [[Bioretention cells|bioretention cell]]. But, if the tank is located below the ground or inside a building the overflow may need a pump.

A simple warm-weather system may capture all of the rooftop runoff in an external tank above grade and use it for sub-surface irrigation. In this scenario the tank can overflow via gravity to a sub-surface [[Infiltration chambers|infiltration chamber]] or a [[Bioretention cells|bioretention cell]]. But, if the tank is located below the ground or inside a building the overflow may need a pump.

<h3>Catchments</h3>

===Catchments===

The origin of the harvested water affects the permissible end uses. Some of the most common uses include irrigation and flushing or toilets and urinals. As mixed source water can only be applied to the more limited end uses, selecting the catchments for a RWH system requires careful consideration.

The origin of the harvested water affects the permissible end uses. Some of the most common uses include irrigation and flushing or toilets and urinals. As mixed source water can only be applied to the more limited end uses, selecting the catchments for a RWH system requires careful consideration.

*The [https://www.ontario.ca/laws/regulation/120332 Ontario Building Code (OBC)] regulates the use of harvested rainwater as one of many non-potable water sources. <em>"Rainwater means storm sewage runoff that is collected from a roof or the ground, but not from accessible patios and driveways."</em>

*The [https://www.ontario.ca/laws/regulation/120332 Ontario Building Code (OBC)] regulates the use of harvested rainwater as one of many non-potable water sources. <em>"Rainwater means storm sewage runoff that is collected from a roof or the ground, but not from accessible patios and driveways."</em>

*The [https://www.iccsafe.org/wp-content/uploads/110116-Draft-CSA_ICC-B805-Rainwater-Harvesting.pdf CSA  standard] separates <em>"roof runoff"</em> from all other sources, including landscaped areas and green roofs. Collectively the green roof/landscaped and paved areas result in <em>"stormwater runoff."</em>   

*The [https://www.iccsafe.org/wp-content/uploads/110116-Draft-CSA_ICC-B805-Rainwater-Harvesting.pdf CSA  standard] separates <em>"roof runoff"</em> from all other sources, including landscaped areas and green roofs. Collectively the green roof/landscaped and paved areas result in <em>"stormwater runoff."</em>   

The current disparity between these two definitions affects all vegetated landscapes including green roofs. Confusion over terminology and regulation has been identified as a significant barrier to implementation of RWH since 2010[http://www.ryerson.ca/content/dam/water/education%20and%20outreach/GreenInfraTO/Identifying%20Barriers%20to%20Widespread%20Implementation%20of%20Rainwater%20Harvesting%20for%20Urban%20Household%20Use%20in%20Ontario.pdf].

The current disparity between these two definitions affects all vegetated landscapes including green roofs. Confusion over terminology and regulation has been identified as a significant barrier to implementation of RWH since 2010[http://www.ryerson.ca/content/dam/water/education%20and%20outreach/GreenInfraTO/Identifying%20Barriers%20to%20Widespread%20Implementation%20of%20Rainwater%20Harvesting%20for%20Urban%20Household%20Use%20in%20Ontario.pdf].

<h4>Cistern and Pipework</h4>

===Cistern and Pipework===

Cisterns must be installed in locations where native soils or the building structure can support the load associated with the volume of stored water. <br>

Cisterns must be installed in locations where native soils or the building structure can support the load associated with the volume of stored water. <br>

Expansion caused by freezing water will damage pipes, pumps and the cistern. There are two options for managing a RWH system in our climate:

Expansion caused by freezing water will damage pipes, pumps and the cistern. There are two options for managing a RWH system in our climate: