FLOOD CONTROL STRATEGY IN SAMPANG CITY, EAST JAVA, INDONESIA

Abstract

Flood always hits Sampang City every year and it causes the transportation disruption in
Madura Island. The flood in Sampang City is caused by four main factors: the watershed (DAS) quality, the
drainage system, the river capacity, and the tide. The flood control strategies that have been done are: the
reduction of flood discharge peak and increasing the river capacity. However, these strategies have not
achieved the significant results yet. Thus a new strategy is needed to solve the problem. The result of
hydrography analysis shows that the discharge is dominated by the surface runoff, thus it indicates that the
quality of DAS is very poor. Further, the land usage in DAS is dominated by the agricultural land such as the
farms and the rice fields. Based on these observations, a new flood control strategy by controlling the surface
runoff on agricultural land is proposed. The strategy is described as the technical activities in the form of
utilization of the farmland partition as the temporary storage facilities. To achieve the maximum result, it
should be followed by the following activities: a) increasing the capacity of interception and infiltration by
the land conservation; b) increasing the capacity of the water reservoir on the land by raising
the embankment design from 30 cm to 50 cm; c) shortening the water puddle time by constructing the
absorption wells. The result of the hydrological analysis shows that the new strategy is able to reduce the
flood discharge peak of 20% to 67%.