When the rainy season arrives inundation occurs in some areas in Palu, the capital city of Central Sulawesi. It’s due to rapid development, outdated drainage systems, high level of sedimentation and the topographic condition. Solutions to overcome the problem are rehabilitating existing drainage, rainwater harvesting, gully plug and temporary storage pond equipped with automatic valve door. Rehabilitation is done by increasing the depth of existing drainage. For rainwater harvesting, the rain barrels capacity varies from 350 - 1050 liters equipped with storage well. By combining the rehabilitation and rainwater harvesting, the effectiveness of inundation reduction in DTA 1 93,5% and in DTA 2 99,6%. For gully plug, each size of gully plug is set to fit the width of channel. The effectiveness of inundation reduction 81% in DTA 1 and 98,9% in DTA 2. The budget plan for rainwater harvesting between Rp. 1.492.505,- to Rp. 2.692.505,- depending on rain barrel capacity. For gully plug between Rp. 556.000,- to Rp. 808.000,- depending on the size of gully plug. Combination of rehabilitation, temporary storage pond equipped with automatic valve door also rainwater harvesting was chosen because the effectiveness of greater reduction and maintenance of rainwater harvesting was much easier