The completion of the Cheung Chun San Tsuen and Kam Tsin Wai river improvement works will minimise the risks of flooding in the area, the Director of Drainage Services Lau Ka-keung says.

Speaking at today's completion ceremony and planting day, Mr Lau said both rivers have now been widened, straightened and deepened, raising the flow capacities to minimise the risks of flooding.

Gabion walls and purpose-made recess blocks are used in the works to enhance the rivers' ecology. More than 600 trees will be planted along the improved rivers.

The works are part of a series of river works in Yuen Long and Kam Tin, which involves improvement to 13 rivers, at a total cost of $600 million. More than 90% of the works are complete.