Changes

[[File:Cistern Size.png|thumb|Schematic diagram of the inputs and outputs to a rainwater harvesting cistern]]

[[File:Cistern Size.png|thumb|Schematic diagram of the inputs and outputs to a rainwater harvesting cistern]]

===Simple===

===Simple===

Five percent of the average annual yield can be estimated:

Five percent of the average annual yield can be estimated:

<math>Y_{0.05} = A_{c} \times C_{vol,A}\times R_{a} \times e \times 0.05</math>

<math>Y_{0.05} = A_{c} \times C_{vol,A}\times R_{a} \times e \times 0.05</math>

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Then the following calculations are based upon two criteria:

Then the following calculations are based upon two criteria:

#A design rainfall depth is to be captured entirely by the RWH system.

# A design rainfall depth is to be captured entirely by the RWH system.

#The average annual demand (''D'') is greater than the average annual yield (''Y'') from the catchment.  

# The average annual demand (''D'') is greater than the average annual yield (''Y'') from the catchment.  

When \(Y_{0.05}/D_{0.05}<0.33\), the storage volume required can be estimated:

When \(Y_{0.05}/D_{0.05}<0.33\), the storage volume required can be estimated:

<math>V_{S} = A_{c} \times C_{vol,E}\times R_{d} \times e</math>

<math>V_{S} = A_{c} \times C_{vol,E}\times R_{d} \times e</math>