Flood Control of Semarang City Plumbon River, Central Java, Indonesia

Abstract

Plumbon River in Semarang City often experiences flooding, even in 2017 and 2018 there were floods and even
overflowed on flood dikes and existing parapets. The purpose of this study was to determine the magnitude of flood
discharge that occurred in the Plumbon River, to find out how high the flood occurred and how far floods started
from the estuary to the upper reaches of the Plumbon River and to find out how to handle the flooding that occurred.
To calculate the flood plan using the Nakayasu Method to get the amount of flood discharge that occurs, with Hec
Ras software to get flood height and far distance that occurs and determine how to handle the flood problems that
occur. The results showed that the magnitude of flooding that occurred based on Q25 th = 43,379 m3 / dt and Q 50
th = 55,239 m3 / dt, and the high flooding that occurred and overflowed on the embankment was as high as 1.00 ms /
d 1.50 m along 3.20 km by handling sheet pile and parapet elevation.