Evaluasi Saluran Drainase Perkotaan di Jalan Langsat Kota Tanjung Selor Kabupaten Bulungan

Abstract

Jalan Langsat is a road in the urban area of Tanjung Selor which is frequently flooded. Inundation occurs when the intensity of rain is high so that the water discharge from the upper reaches of the Kayan River is more than usual, which causes the drainage channels to be unable to accommodate the flowing water discharge. This is due to the decreased capacity of the channel and increased flow rate, besides that the drainage channel is experiencing siltation due to the large amount of garbage and sediment in the drainage channel. This study aims to determine the capacity of existing drainage channels to accommodate and drain rainwater discharge. The method used in this study is the evaluative method with primary and secondary data collection stages, then data analysis is hydrological analysis with four methods, namely the Normal distribution method, Normal Log, Log Person III and Gumbel and canal hydraulic analysis. The results of the calculation used to determine the planned rainfall intensity are the Log Normal distribution with a return period of 10 years of 527,228 mm/hour. The calculation of rainfall intensity is used by the Mononnobe formula, while for the evaluation of channel capacity, the evaluative method is used by comparing the channel capacity with the design discharge. Where Qs > Qr then the channel capacity is safe, and if Qs < Qr then the channel capacity is not safe. From the results of the evaluation of the capacity of the drainage channels, there were 23 channels reviewed, 15 channels that were unsafe and 8 channels that were safe. Furthermore, the choice of problem handling at the study location, namely for channels that are declared safe, canal normalization is carried out and for channels that are unsafe or overflow, re-planning of channel dimensions is carried out.