SIMULATION OF URBAN DRAINAGE SYSTEM USING SCS HYDROGRAPH METHOD

Most of the computer models can fully account for the quantitative aspect in all
the hydrologic and hydraulic design stages. The aim of this paper is to evaluate
the capabilities of PONDPACK model to analyse the drainage network and
pond capacity to cater stormwater runoff from residential areas. Based on actual
and design rainfall data, PONDPACK can generate the peak discharges for each
sub-catchment for pre and post development. PONDPACK model can produce
the analysis of drainage network using Rational Method and SCS hydrograph
methods. Pond routing can be generated using Modified Puls Method or
Muskingum Method. Result has shown PONDPACK performed well using SCS
Hydrograph method compared to Modified Rational Method where it can
generate the peak runoff for each sub-catchment. Besides, it also can produce
flow and storage routing for each link and pond system. However, Modified
Rational method can only generate peak discharge from single catchment area.
Since this method is not able to generate hydrograph, it is also not applicable in
performing flow routing. In 20 years ARI, detention pond capacity will achieve
up to 2800 m3. PONDPACK is applicable in the design and analysis of drainage
network and pond system with some modifications such as the CN values to
suite with Malaysian condition.