STUDI EVALUASI SISTEM JARINGAN DRAINASE (STUDI KASUS: JALAN RAYA PANGGUNGREJO, KEPANJEN, KABUPATEN MALANG)

At several points in the city of Kepanjen, flooding often occurs when the rainy season arrives. One of these points is in Panggungrejo Village, especially on the Jalan Raya Panggungrejo road. When heavy rain hits for a long time, this road section becomes prone to flooding every year. The irrigation river on the edge of Jalan Raya Panggungrejo has a fairly shallow depth, and the drainage channel is not functioning optimally, making it unable to accommodate the discharge from rainwater. Therefore, it is very important to check the local drainage system. To carry out the analysis, hydrological analysis and hydraulic analysis are carried out. In hydrological analysis, apply the Log Person III method, the Chi square suitability test, Smirnov Kolmogorov, Monobe, and rational. for hydraulic analysis using the Stickler method. Calculations show that the flood discharge for a 10-year return period is 133 mm. Based on calculations, the channel cross-section discharge 100–104 does not meet the design flood discharge. For this reason, the dimensions must be changed so that the discharge at the cross section exceeds the design flood discharge. Finally, it was necessary to change the dimensions of several channels. Channel 100, which was previously built with dimensions of 1.0 x 1.0 m, must be redesigned with dimensions of 1.0 x 1.6 m. Channel 101–103 with dimensions of 1.0 m x 1.0 m must be redesigned with dimensions of 1.2 x 1.8 m. Channel 104, measuring 1.0 m x 1.0 m, must be redesigned with dimensions of 1.5 x 1.8 m.