Abstract

Storm water management and road tunnel (SMART) was built to direct water around a major meeting point of two major rivers located in a large urban area; in addition, it doubles up as a road tunnel, though that section is only used in major storms. Much information has come from the Malaysian Department of Irrigation and Drainage (DID), in the form of data and reports. Pre-project historical water flow data as well as a simple velocity-area calculation to find the tunnel capacity was used to assess its efficiency. Water level data from the DID was used to create a graph in order to calculate the minimum amount of water to create flooding. Processing this information has revealed that SMART is in itself an effective flood deterrent, due to its water capacity and the lag time it creates. Although most storms should be easily dealt with, SMART only diverts water around the critical meeting point from one of the contributing rivers. It has no effect on the flow from the other river but it caused the sustained water to flow out. For an example, rainfall from a 100 year average return interval from this river will flood Kuala Lumpur. Although the development of SMART has been considered as successful, however, the growing development in the other part of the city could not ensure no flooding will take place or thoroughly protect the city centre.

Key words: Discharge, confluence, rainfall, storm water, drainage, frequency.