Evaluasi Kapasitas Saluran Drainase Desa Sariharjo Ngaglik Sleman YOGYAKARTA

Along Palagan Tentara Pelajar Street, rainfall runoff floods Sariharjo area regularly.The inundation is triggered by drainage channel that cannot convey rainfall runoff therefore itfloods street and settlement. Flood mitigation is conducted by evaluating existing channelcapacity. Several analyses were carried out such as evaluation of existing drainage network,calculation of flood discharge, and channel hydraulic calculation. Flood discharge is analyzed byusing rational method, and channel conveyance discharge is calculated by using Manningequation. Forty masonry channels were evaluated to determine their discharge conveyance. Theywere evaluated by using areal rainfall discharge method, and street drainage method at 5 yearsreturn flood discharge. All of channels cannot convey areal rainfall discharge. Moreover therewere 5 channels that cannot convey flood discharge calculated by using street drainagemethod. Dimension improvement is needed to overcome inundation. Channel width must beincreased from 0.30 m to 0.60 m, and channel height must be improved 0.60 m to 0.90 m