Changes

Five percent of the average annual demand can be estimated:

Five percent of the average annual demand can be estimated:

<math>D_{0.05} = P_{d} \times #\times 18.25</math>

<math>D_{0.05} = P_{d} \times n\times 18.25</math>

{{plainlist|Where:

{{plainlist|Where:

*''D_0.05'' is five percent of the average annual demand (L)

*''D_0.05'' is five percent of the average annual demand (L)

*''P_d'' is the daily demand per person (L)

*''P_d'' is the daily demand per person (L)

*''#'' is the number of occupants}}

*''n'' is the number of occupants}}

Then the following calculations are based upon two criteria:

Then the following calculations are based upon two criteria:

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 \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>

{{plainlist|Where:

{{plainlist|Where:

*''V_S'' &#61; Storage volume required (L)

*''V_S'' is the volume of storage required (L)

*''A'' &#61; The catchment area (m²)

*''A_c'' is the catchment area (m²)

*''C_vol,E'' &#61; The design storm runoff coefficient for the catchment

*''C_vol,E'' is the design storm runoff coefficient for the catchment

*''R_d'' &#61; The design storm rainfall depth (mm), and

*''R_d'' is the design storm rainfall depth (mm), and

*''e'' &#61; The efficiency of the pre-storage filter.}}

*''e'' is the efficiency of the pre-storage filter.}}

*Careful catchment selection means that the runoff coefficient, for a rainstorm event (''C_{vol, E}'') should be 0.9 or greater.

*Careful catchment selection means that the runoff coefficient, for an individual rainstorm event (''C_{vol, E}'') should be 0.9 or greater.

          

          

Finally, when \(0.33<Y_{0.05}/D_{0.05}<0.7\), the total storage required can be estimated by adding ''Y_0.05'':

Finally, when \(0.33<Y_{0.05}/D_{0.05}<0.7\), the total storage required can be estimated by adding ''Y_0.05'':