In the past, spontaneous development in the New Territories frequently occurred, usually with little regard to the adverse impact on the drainage systems in the areas. The filling of fishponds and low lying areas within the flood plains to form large paved storage yards has increased surface flows and blocked the drainage paths. To address this problem, land use management measures are now in place to ensure that the current flooding situation will not deteriorate due to further development and urbanisation on the New Territories' floodplain.

Development control is enforced through the Outline Zoning Plans (OZPs), the Town Planning Ordinance and the Drainage Impact Assessment requirements. All development requiring a change to the land use as specified in the OZPs or other Government development plans will need to seek approval from the Town Planning Board. If the project will significantly affect the drainage situation, private developers or the proponents of public projects, such as reclamation and highway projects, will need to conduct a Drainage Impact Assessment to demonstrate that, with their proposed mitigation measures, the flooding risk to the area concerned would not be increased. These management measures are a significant element in determining the need, scope and timing for the structural measures to be implemented, and in allowing development in the floodplain to proceed in a proper and controlled manner whilst the long term structural measures are being implemented.

Advice Note No 1 - Application of the Drainage Impact Assessment Process to private section projects (PDF format, 35KB)