Socio-Economic Analysis of Creating Coastal Reservoir in Welang Coastal Area, Pasuruan: Comparison with on-land Reservoir

Welang river is located in a residential area and national road access as well as a productive agricultural area which must be maintained. Floods that often hit the location disrupt economic activity and regional economic growth. The estuary and the capacity of the river sections, especially around the estuary are not able to accommodate and drain the flood discharge. The flood overflows caused inundation in Pasuruan, especially on national roads, agricultural lands, and industrial areas. To control the destructive power of the Welang river, it is necessary to plan an appropriate infrastructure for flood control in the Welang River especially when the high water discharge meets the high tide. This paper discusses the comparison between coastal and on-land reservoirs. In addition, based on economic analysis, the Benefit-Cost Ratio for on-land reservoirs is 1 and for coastal reservoirs is 1,54. Therefore, the coastal reservoir project is more economically feasible to carry out than an on-land reservoir with less social impact. This study also shows that with the use of the coastal reservoirs, the river runoff, water supply, and the water quality in Welang river basins can be improved.