Line 7: |
Line 7: |
| | | |
| ==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> | + | [[Rainwater harvesting|Rainwater harvesting (RWH)]] is ideal for high density, zero-lot-line developments, large garden and landscape areas, and sites that cannot infiltrate water (e.g. contaminated soils, WHPAs, IPZs, etc.). 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: |
Line 15: |
Line 15: |
| | | |
| ===Notes=== | | ===Notes=== |
− | * Overflow was not costed as it would be needed even if the RWH system was not constructed. | + | * Two (2) German-style in-line filters and precast concrete containment structures are included to provide pretreatment of roof runoff. |
− | * Costs for conveyance piping are not included in the model design for indoor tanks because conveyance would be needed even without RWH.
| |
− | * The cost for decommissioning an outdoor above-ground plastic tank for [[#Cold climate considerations#Winter Management|the winter]] is not included.
| |
− | * 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. |
Line 30: |
Line 27: |
| ==Construction Costs== | | ==Construction Costs== |
| | | |
− | [[File:Construction Breakdown RWH No Infil.PNG|thumb|center|950px|'''Construction Costs Per Unit Drainage Area (CAD$/m<sup>2</sup>) - No Infiltration Design, 25 mm Treatment''']] | + | [[File:Construction Breakdown RWH No Infil 2023.PNG|thumb|center|950px|'''Construction Costs Per Unit Drainage Area (CAD$/m<sup>2</sup>) - No Infiltration Design, 25 mm Treatment''']] |
− | | |
| | | |
| <small>'''Note:''' Please click on each image to enlarge to view associated construction cost estimates.</small><br> | | <small>'''Note:''' Please click on each image to enlarge to view associated construction cost estimates.</small><br> |
| | | |
| | | |
− | Above you can find a cost breakdown of a below-ground concrete cistern that possesses a 50,000L capacity limit in the following configurations type:<br> | + | Above you can find a breakdown of construction costs by expense type for the 50,000 L below-ground concrete cistern design configuration. |
− | #[[Rainwater harvesting|Rainwater Harvesting: No Infiltration]]
| |
| | | |
− | The Material & Installation expenses represent the largest portion of total construction costs (84%). | + | The Material & Installation expenses represent the largest portion of total construction costs (86%). |
| | | |
| ==Life Cycle Costs== | | ==Life Cycle Costs== |
− | Below are capital and life cycle cost estimates for an [[Rainwater harvesting|Underground Rainwater Cistern]], Non-Infiltrating configuration over 25- and 50-year time periods. The estimates of maintenance and rehabilitation (life cycle) costs represent net present values. Operation and maintenance costs are predicted to represent 18% of total life cycle costs over the 25-year evaluation period, and increase to 26% of total life cycle costs over the 50-year period, due to increased levels of litter removal, cleaning out of tank, cleaning the in-line filter, replacing components (pump and pressure tank), cistern pump performance testing. | + | Below are capital and life cycle cost estimates for the below-ground concrete cistern design configuration over 25- and 50-year time periods. The estimates of maintenance and rehabilitation (life cycle) costs represent net present values. Operation and maintenance costs are predicted to represent 19% of total life cycle costs over the 25-year evaluation period, and increase to 27% of total life cycle costs over the 50-year period, due to periodic cleaning of cistern tank and replacing of components (pump and pressure tank). |
| | | |
| ===25-Year life cycle cost break down=== | | ===25-Year life cycle cost break down=== |
| | | |
− | [[File:25yr LCCT RWH No Infil.PNG|thumb|center|900px|'''Rainwater Harvesting: No Infiltration''']] | + | [[File:25yr LCCT RWH No Infil 2023.PNG|thumb|center|900px|'''Rainwater Harvesting: No Infiltration''']] |
| | | |
| <small>'''Note:''' Click on each image to enlarge to view associated life cycle cost estimate.</small><br> | | <small>'''Note:''' Click on each image to enlarge to view associated life cycle cost estimate.</small><br> |
| + | </br> |
| | | |
| ===50-Year life cycle cost break down=== | | ===50-Year life cycle cost break down=== |
| | | |
− | [[File:50yr LCCT RWH No Infil.PNG|thumb|center|900px|'''Rainwater Harvesting: No Infiltration''']] | + | [[File:50yr LCCT RWH No Infil 2023.PNG|thumb|center|900px|'''Rainwater Harvesting: No Infiltration''']] |
| | | |
| <small>'''Note:''' Click on each image to enlarge to view associated life cycle cost estimate.</small><br> | | <small>'''Note:''' Click on each image to enlarge to view associated life cycle cost estimate.</small><br> |
| | | |
| ==Cost Summary Tables== | | ==Cost Summary Tables== |
− | Total life cycle cost estimates for an [[Rainwater harvesting|Underground Rainwater Cistern]], Non-Infiltrating configuration is ($92,343.04), making it one of the cheapest LID BMP options.<br> | + | Total life cycle cost estimate over the 50 year evaluation period for the below-ground concrete cistern design configuration is ($124,016.80), making it one of the cheapest LID BMP options.<br> |
| | | |
− | ===Full Infiltration=== | + | ===No Infiltration=== |
− | [[File:RWH rain barrel.PNG|500px|thumb|A residential [[rain barrels|rain barrel]] collecting roofwater from the house installed with a diverter to ensure water does not overflow the system when full and allows water to instead bypass the barrel and enter directly into the storm sewer through a storm lateral or enter an on site [[dry swale]] or [[infiltration trench]], if installed.]] | + | [[File:RWH rain barrel.PNG|700px|thumb|A residential [[rain barrels|rain barrel]] collecting roofwater from the house installed with a diverter to ensure water does not overflow the system when full and allows water to instead bypass the barrel and enter directly into the storm sewer through a storm lateral or enter an on site [[dry swale]] or [[infiltration trench]], if installed.]] |
| | | |
− | [[File:Design Table RWH No Infil.PNG|700px]]<br> | + | [[File:Design Table RWH No Infil 2023.PNG|900px]]<br> |
| </br> | | </br> |