Changes

[[File:RAINWATER HARVESTING TANK 550x550.jpg|thumb|Large cistern being installed underground]]

[[File:RAINWATER HARVESTING TANK 550x550.jpg|thumb|Large cistern being installed underground]]

[[File:RWH.gif|thumb|Conceptual diagram of an underground cistern being used for irrigation]]

[[File:RWH.gif|thumb|Conceptual diagram of an underground cistern being used for irrigation]]

[[Rainwater Harvesting: Sizing and Modelling]]

{{:Rainwater Harvesting: Sizing and Modelling}}

<h3>Catchments</h3>

<h3>Catchments</h3>

Decisions need to be made about the selection and grading of catchments. If one catchment is very large, can it be regraded to drain to two or more outlets? Is it desirable to capture both rooftop water and other stormwater? This will may determine the quality improvements required to  use the water. See table below, which illustrates the higher treatment required for storm water (i.e. non-rooftop).

Decisions need to be made about the selection and grading of catchments. If one catchment is very large, can it be regraded to drain to two or more outlets? Is it desirable to capture both rooftop water and other stormwater? This will may determine the quality improvements required to  use the water. See table below, which illustrates the higher treatment required for storm water (i.e. non-rooftop).