Changes

Jump to navigation Jump to search
Line 25: Line 25:
#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<sub>0.05</sub>/ D<sub>0.05</sub> < 0.33, the storage volume required can be estimated:
 
<br><strong>V<sub>S</sub> = A × C<sub>vol</sub> × R<sub>d</sub> × e</strong>
{{textbox|{{plainlist|
<br>V<sub>S</sub> = Storage volume required (L)
*When Y<sub>0.05</sub>/ D<sub>0.05</sub> < 0.33, the storage volume required can be estimated:
<br>A = The catchment area (m<sup>2</sup>)
*<strong>V<sub>S</sub> &#61; A × C<sub>vol</sub> × R<sub>d</sub> × e</strong>
<br>C<sub>vol, E</sub> = The design storm runoff coefficient for the catchment
*V<sub>S</sub> &#61; Storage volume required (L)
<br>R<sub>d</sub> = The design storm rainfall depth (mm), and
*A &#61; The catchment area (m<sup>2</sup>)
<br>e = The efficiency of the pre-storage filter.
*C<sub>vol, E</sub> &#61; The design storm runoff coefficient for the catchment
/*Good catchment selection means that the runoff coefficient, for a rainstorm event (C<sub>vol, E</sub>) should be 0.9 or greater.
*R<sub>d</sub> &#61; The design storm rainfall depth (mm), and
*e &#61; The efficiency of the pre-storage filter.}}}}
 
/*Careful catchment selection means that the runoff coefficient, for a rainstorm event (C<sub>vol, E</sub>) should be 0.9 or greater.
          
          
When 0.33 < Y<sub>0.05</sub>/ D<sub>0.05</sub>< 0.7, the total storage required can be estimated by adding Y<sub>0.05</sub>:
When 0.33 < Y<sub>0.05</sub>/ D<sub>0.05</sub>< 0.7, the total storage required can be estimated by adding Y<sub>0.05</sub>:

Navigation menu