SCG 31030 Stormwater Management Plan · OPW22/0319

Using the software package DRAINS we have modelled the proposed site with a dentention tank to establish the
proposed stormwater drainage characterisitics. The detention tank was modelled with a 135 diamater slow flow
orifice and only receives runoff from the roofs of the proposed buildings.




                             Fig 2 – Drains Model – Showing 1% AEP Flows




                   Fig 3 – Proposed Detention Tank Volume/Site Discharge Flow Rate



 SCG Consulting engineers                             8                              SCG Ref: 31030(SWM)


[OCR of page images]
Using the software package DRAINS we have modelled the proposed site with a dentention tank to establish the
proposed stormwater drainage characterisitics. The detention tank was modelled with a 135 diamater slow flow
orifice and only receives runoff from the roofs of the proposed buildings.

Qo.149

0.167

PROPOSED SITE

EXISTING SITE

Volume (cu.m)

Flow rate (cu.m/s)

 

so ee ———

ane <A 7

\
en 0135
-

PROPOSED SITE - DETAINED

Fig 2 — Drains Model — Showing 1% AEP Flows

TANK STORAGE VOLUME - 1% AEP, 10min burst Storm 7

 

° 10 20 30 40 50 60
Time (mins)

PIPE 15 Hydrograph - 1% AEP, 10min burst Storm 7

 

Maximum flow = 0.135 cu.m/s

 

0 10 20 30 40 50 60
Time (mins)

Fig 3 — Proposed Detention Tank Volume/Site Discharge Flow Rate

SCG Consulting engineers

8 SCG Ref: _31030(SWM)