STUDI EVALUASI DAN PERENCANAAN SISTEM DRAINASE JALAN KALI BRANTAS KOTA BLITAR

Currently, flooding is a common problem plaguing urban areas in Indonesia. Drainage issues require immediate and serious attention. One of the roads in the city of Blitar is Jalan Kali Brantas. A section of Jalan Kali Brantas is approximately 1,500 meters long and is classified as a secondary collector road because it connects the second secondary area with the second secondary area or the second secondary area with the third secondary area. Waterlogging has occurred on this road due to overflow from the drainage channels. The overflow occurred because the drainage channels were unable to accommodate the water flow caused by heavy rainfall. As a result of the flooding, the activities of the community in the surrounding area and those wishing to pass through Kali Brantas Road in Blitar City have been disrupted.
The objective of this study is to determine the flood discharge based on a 5-year design rainfall, the inflow of stormwater into the drainage system, and the capacity of the drainage system for the redesign of the new drainage system on Kali Brantas Street in Blitar City. Rainwater discharge can be calculated by analyzing channel dimensions based on the volume of rainwater to be conveyed using the rational method. This method can describe the relationship between runoff discharge and rainfall intensity for watershed areas up to 300 ha.
The research results show that (1) the maximum rainfall with a 5-year return period at the study site is 92.608 mm, and the design flood discharge is 0.061 m³/s. (2) There are several channels that cannot accommodate the existing design flood discharge. These channels are: SP. KAL – KI 2, SP. KAL – KI 3, and SP. KAL – KA 2. (3) There are channels that cannot accommodate the design flood discharge and require redesign, namely SP. KAL – KI 2, SP. KAL – KI 3, and SP. KAL – KA 2.