Rethinking erosion and sedimentation control

With the recent increased frequency of severe floodings in the Klang Valley, should we reconsider how managing erosion and sedimentation during construction is approached in Malaysia?

Disturbance of land for development, which includes clearing and cutting land during construction, when exposed to rainfall and surface run-off in an unmanaged way causes erosion and subsequent deposit of sedimentation into public drainage networks and watercourses. In addition to being a key waterway pollutant, the sedimentation also reduces the capacity of public drainage networks if the networks are not maintained to suit, which in return contributes to flooding.

Although managing erosion and sedimentation from construction is only one aspect of stormwater management, given the extent of development in the Klang Valley, it is an aspect that cannot be overlooked and requires effective implementation. And it can only be effectively implemented when statutory requirements are developed with an understanding of the construction process and roles of the parties involved.

At present, the local councils require the civil engineer responsible for a development to submit an erosion and sediment control plan (known in the industry as ESCP) for the construction during the application to seek approval for the development (as part of the earthworks application, ahead of the appointment of the contractor). This consequently makes the engineer statutorily liable for a development's erosion and sedimentation management.

Is this the best way to effectively implement erosion and sedimentation management during construction? I do not think so for these reasons:

• For a development, the contractor does the planning and execution of the construction activities (approach, sequence of works, the temporary works and machinery needed). This varies from contractor to contractor and cannot be dictated by the civil engineer (it is simply not how the industry works).
• As ESCP is essentially a type of temporary work (i.e. not a permanent measure), it is best undertaken by the contractor, and he is made liable for it. At present, the contractor and not the engineer is responsible for temporary works during construction, and it should not be any different with ESCP.

With this, I propose this approach:

• ESCP is removed from the earthworks application and is made a standalone application.
• The contractor makes this application before the commencement of construction. This is similar to the permit application for the waste disposal lorries, a process undertaken by the contractor before the commencement of construction.
• As with all other temporary works, the ESCP is developed by the contractor's temporary works engineer. This engineer bears the statutory liability for managing erosion and sedimentation during construction.
• The council must require the ESCP to be a comprehensive plan which includes details of the planned progression of land clearance and earthworks with details of how the proposed temporary works correspond to this planned progression (At present, the councils do not require such a comprehensive plan.).

As mentioned above, successful management of erosion and sedimentation during construction is only possible if regulators implement requirements and legislation with an understanding of the industry and its ways (and of course, proper enforcement which is a whole topic by itself!). Else, it will only be a futile exercise, as it currently is.

By Yasotha Chetty

Published on 30 Apr 2022

Pink Musings are reflections on our encounters within the Malaysian built environment and as a contribution towards upholding it.

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