← Water
H04-03 · Module 3 of 7 · Pages: 20 · Worksheets: 7
Rainwater harvesting: gutters, cisterns and tanks
How much water your roof gives, how to get it clean into the tank, how big the tank should be and how to install and look after it
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Whole series: Water, €39
In short
- 1 mm of rain on 1 m² of roof = 1 litre. In practice you collect 60–90 %, depending on the roof.
- Divert the first 0.5–1 litre per m² of roof from every shower: that is dust, bird droppings and leaves.
- Size the tank for the longest dry spell, not for the yearly total.
- 1 m³ of water weighs 1 tonne. Base, burial and concrete are planned with that in mind.
- Rainwater is not drinkable without filtering, disinfection and a lab test. Rainwater pipes are never connected to the mains.
What's inside
Chapters
- How much water your roof gives
- Gutters, downpipes and leaf filters
- First flush
- Tanks and cisterns
- How big a tank
- Installing the tank step by step
- Rainwater in the house
- Maintenance through the year
- Common mistakes
- Printable checklist
Worksheets
- Roof calculator
- Tank calculator
- Tank comparison
- Rainwater system plan
- Tank log
- Rainwater calendar
- Shopping list
Fields and checkboxes can be filled in with Adobe Acrobat Reader (desktop and mobile), and the calculator adds up by itself. Filling in may not work in some browsers. A print version comes with the screen PDF.
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