Cistern size can be estimated by multiplying the depth
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<img src = "http://mediawiki.trca.info/images/thumb/9/9d/Cistern_Size.png/800px-Cistern_Size.png" alt="schematic diagram shows rainwater and top-up as inputs to rainwater harvesting cistern, and outputs are irrigation, other non-potable uses, and overflow" width = 200>
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[[file:Cistern_Size.png | thumb |Caption]]
<h4>Rapid</h4>
Cistern size can be estimated by multiplying the depth