The first urban drainage manual, ‘Planning and Design Procedures No. 1:Urban Drainage Design Standards and Procedures for Peninsular Malaysia’ was published by DID in 1975. This manual was prepared as a guideline for engineers in designing drainage system and had been referred to by various agencies at federal and state level for the drainage requirements needed for any development in urban areas.  The manual has been in used as a guideline for more than twenty five years and since its publication, changes have not been made although there have been  many new technological developments in urban drainage.

It is time to take a proactive measure to change the manual to incorporate the latest development in stormwater management that is known as control-at-source approach. This approach utilizes detention/retention, infiltration and purification processes. The quality and quantity of the runoff from developing area can be maintained to be the same as predevelopment condition. The beauty of using control-at-source method are: Drain size needed in the urban area is smaller and comparable with the predevelopment condition; Stormwater runoff effect is reduced; There is an integration of environmental friendly drainage infrastructures and the landscape, developing natural harmony. As an example, if a swale (ground drainage which is covered with grasses) is constructed to replace concrete drain at the road side, it can function as stormwater discharge storage agent and filter pollutants from non-point source such as grease from vehicles. The swale also can be part of landscaped area that will be decorated with trees and flower plants.

This new approach is more environmental friendly and capable of integrating other facilities. Examples are, landscaped area and temporary stormwater storage facilities in car parks and playgrounds. At the  Federal Government Administrative Center Putrajaya, this new approach has been applied by incorporating the lake and wetland as storage and purifier of stormwater. There are places utilizing this new approach such as Sierramas in Kepong, Selangor, Diamond Creek in Tanjung Malim, Perak and Leisure Farm in Johor. Stormwater collection tank and retention pond, described in the Stormwater Collection Guidelines published by Housing and Local Government Ministry in 1998 and Guidelines for Retention Pond Area as Part of Open Space published by Department of Town and Rural Planning (Piawaian Perancangan JPBD 4/97), are among the suitable methods that can be used as control at source infrastructures. Utilizing control at source approach can also result in maintaining  a harmonious environment for urban community, increasing its aesthetic value and therefore increasing the value of the properties.   The use of environmental friendly approach is expected to happen sooner or later. However, based on development in other countries, this will probably take 15 (fifteen) years without any proactive initiatives. Hence, Department of Irrigation and Drainage has prepared this second urban drainage manual which is titled the Stormwater Management Manual so that this new concept can be immediately implemented and administered in a systematic manner and with a faster approach.

The Stormwater Management Manual is prepared by DID to replace the first manual. It is more comprehensive, taking into consideration the present problems facing by the nation such as flash flood, river pollution, soil erosion, development in the highlands and lowlands and so on. Latest development based on control at source approach has also been documented. This manual has also been reviewed by various agencies, organizations and foreign experts. Where applicable, their views are taken into consideration in preparing the final document.

The Purpose of this Manual Goal and Objectives The goal of this Manual is to provide guidance to all regulators, planners and designers who are involved in stormwater management implementation, which is often undertaken by a number of organisations. The challenge is to ensure that the administration of the planning, design and maintenance of stormwater management systems is consistent across the relevant Local, State and Federal Authorities and the professions of planning, environmental and civil engineering, and landscape architecture. Under this new direction, stormwater management will have multiple objectives, including to:   Ensure the safety of the public; Control nuisance flooding and provide for the safe passage of less frequent and larger flood events; Stabilise the landform and control erosion; Minimise the environmental impact of runoff; and ; enhance the urban landscape.   Scope This manual covers all aspects and requirements of stormwater management for urban areas throughout Malaysia.

While this Manual does not specify requirements for stormwater management in rural areas, many of the actions, measures and techniques presented in this Manual could be applied in rural areas as appropriate. Related Documents This Manual is supported by a number of other related documents that cover aspects of stormwater management.  These documents should be also considered when planning urban development and/or designing stormwater management infrastructure.  The documents are: Design Guides for Erosion and Sediment Control in Malaysia, Department of Irrigation and Drainage, 2010 Guidelines on River Front Development, Federal Department of Irrigation and Drainage Malaysia Guidelines on the Prevention and Control of Soil Erosion and Siltation in Malaysia, Department of Environment, 1996 Use of Flood Detention Ponds as Part of Open Space, JPBD