Assessment of surface run-off potential in the Klandasan Kecil watershed

Klandasan Kecil Watershed become one of the crucial areas affected by the flood, from 42 flood points in Balikpapan, more than 40% of which are located in this area. The watershed is the centre of the city government and the commerce and services centre in Balikpapan. If a flood occurs, it will affect all urban activity. The city government has made several efforts to deal with the flood. They are still not effective because it was conducted to drain water without increasing the recharge area’s function. In making prevention, it is necessary to assess flood discharge due to existing rivers and waterways have limited storage capacity. Therefore, an estimation of surface runoff in the Klandasan Kecil Watershedneeds to be done to determine the direction of flood mitigation. The analysis shows that the surface runoff volume in this area is half a million m3, with a maximum hydrology discharge of 95,44 m3/s. The amount of surface runoff is so far fromthe existing channel’s capacity that it can only accommodate 48,485 m3. The estimated flooding can occur for one million m3 with a large flood discharge of 42,41 m3/s.