MSMA- A NEW URBAN STORMWATER MANAGEMENT MANUAL FOR MALAYSIA

The Malaysian economy has gone through rapid structural changes since independence in 1957. Progressive development from agriculture to an industrialized economy has shifted the population into urban centers. Urban development is necessarily to meet the need of urban population. Urbanization will increase the construction of paved area that has significant changed on the hydrologic and hydraulic characteristics of the catchments. Therefore not surprisingly, incidence of flash flood in urban area in Malaysia is becoming more severe from year to year. In order to mitigate flash flood in urban area, a conventional drainage system has been designed to provide the fastest possible transport of storm water runoff out of the catchments into the receiving water. In Malaysia, conventional drainage system is based on the first urban drainage manual “ Planning and Design Procedure No.1: Urban Drainage Design Standards and Procedure for Malaysia” was published by DID in 1975. This manual has been used as a guideline for more than twenty-five years and since its publication, although there have been many new technological developments in urban area. Conventional drainage system, unfortunately has led to increase the occurrence of flash flood at the downstream of the catchments. Additionally, open drainage invites more polluted river and therefore has worsened the quality of life in urban community. Therefore conventional drainage is no longer an effective measure in solving flood. Due to this problem, Department of Irrigation and Drainage (DID) Malaysia is taking a proactive step by introducing New Urban Drainage Manual known as Storm Water Management Manual for Malaysia (Manual Saliran Mesra Alam or MSMA). From 1 st January 2001 onward all new development in Malaysia must comply with new guideline that requires the application of Best Management Practices (BMPs) to control stormwater from the aspect of quantity and quality runoff to achieve zero development impact contribution. These concepts of BMPs will be able to preserve the natural river flow carrying capacity.