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==Design Assumptions==
 
==Design Assumptions==
[[Rainwater harvesting|Rainwater harvesting (RWH)]] is ideal for sites that cannot infiltrate water (e.g. contaminated soils, WHPAs, IPZs, etc.), zero-lot-line developments, large gardens and landscaped areas. Components include: catchment area (e.g. rooftop), [[Pretreatment| pretreatment]] filter to remove coarse debris, cistern storage, and a connecting pipe network. Additional components include pumps to lift water to higher elevations, additional water filtration and treatment. <br>
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[[Rainwater harvesting|Rainwater harvesting (RWH)]] is ideal for sites that cannot infiltrate water (e.g. contaminated soils, WHPAs, IPZs, etc.), zero-lot-line developments, large gardens and landscaped areas. Components include: catchment area (e.g. rooftop), pretreatment filter to remove coarse debris, cistern storage, and a connecting pipe network. Additional components include pumps to lift water to higher elevations, additional water filtration and treatment. <br>
    
Design and operation and maintenance program assumptions used to generate the cost estimate are based on tool default values and the following STEP recommendations:
 
Design and operation and maintenance program assumptions used to generate the cost estimate are based on tool default values and the following STEP recommendations:
 
* Total daily water use of 2,000 L per day (tool default).
 
* Total daily water use of 2,000 L per day (tool default).
 
* User specified storage tank capacity of 50,000 L.
 
* User specified storage tank capacity of 50,000 L.
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* Two (2) German-style in-line filters and precast concrete containment structures are included to provide pretreatment of roof runoff.
 
* Operation and maintenance (O&M) cost estimates assume annual inspections and cistern pump tests, removal of trash and debris from rooftop and pretreatment filter four times a year, and cleaning of cistern and replacement of pump and pressure tank every five years. Verification inspections are included every 5 years to confirm adequate maintenance.
 
* Operation and maintenance (O&M) cost estimates assume annual inspections and cistern pump tests, removal of trash and debris from rooftop and pretreatment filter four times a year, and cleaning of cistern and replacement of pump and pressure tank every five years. Verification inspections are included every 5 years to confirm adequate maintenance.
    
===Notes===
 
===Notes===
* Overflow was not costed as it would be needed even if the RWH system was not constructed.
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* Costs for conveyance piping are not included in the model design for indoor tanks because conveyance would be needed even without RWH.
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* The cost for decommissioning an outdoor above-ground plastic tank for [[#Cold climate considerations#Winter Management|the winter]] is not included.
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* The tool assumes that only one trench is needed for all piping, including conveyance, service and top-up piping.
   
* The tool calculates costs for new (greenfield) development contexts and includes costs for contractor overhead and profit, material, delivery, labour, equipment (rental, operating and operator costs), hauling and disposal.  
 
* The tool calculates costs for new (greenfield) development contexts and includes costs for contractor overhead and profit, material, delivery, labour, equipment (rental, operating and operator costs), hauling and disposal.  
 
** Land value and equipment mobilization and demobilization costs are not included, assuming BMP construction is part of overall development site construction.
 
** Land value and equipment mobilization and demobilization costs are not included, assuming BMP construction is part of overall development site construction.

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