Evaluasi Unjuk Kerja Jaringan Drainase di Daerah Ngesrep, Ngemplak, Boyolali

Roads in Ngesrep Village, Ngemplak, Boyolali often inundate when the rainy season arrives. The inundation is caused by the drainage system at the location is not optimum because siltation has occurred due to sedimentation. To find out the performance of drainage channels in the area, a hydrological analysis was performed to calculate the plan discharge with a 25-year return period using the Log Person Type III method. The results of the calculations performed show the value of the planned discharge is greater than the value of the existing discharge (Qrencana = 2.3105 m³ / sec> Qexisting = 0.4189 m³ / sec) so that the existing channel is unable to accommodate the planned discharge that occurs in the Ngesrep area. It is necessary to re-plan the dimensions of the channel by using an economical drainage design and a planned cross section of the trapezoidal channel using material on the channel wall in the form of river stones. The calculation results obtained by the dimensions of the channel dimensions using the peak Q value as a reference that is the width of the base channel, (b = 94.5644 cm), depth (h = 76.5042 cm) and width of the upper channel, (B = 171.069 cm)