THE RELIABILITY STUDY OF RAW WATER SOURCES IN THE DEVELOPMENT OF POTABLE WATER SUPPLY SYSTEMS IN INDONESIA

Abstract

To fulfill the demands of raw water for potable water purposes in various parts of Indonesia,
dependable water resources, especially from surface water are needed. During the dry seasons, difficulties
arise in fulfilling these demands. This study aims to identify dependable discharge in three locations with
different rainfall types. The first step in fulfilling the raw water demand is analyzing the hydrological data
using the theoretical and Markov model to determine the dependable discharge based on the type of rainfall.
The calculation shows that the suitable distribution test for Cidurian River, Landak River, and Selindung
River, respectively are Pearson III Logs, Normal Logs, and Normal Logs. The dependability of Cidurian
River discharge with a watershed area of 9.38 km2
in the Tangerang Regency with a monsoon rainfall rate is
0.325 m3
/s, whereas Landak River, which is located in Pontianak City with an equatorial rainfall type and a
watershed area of 624.27 km2
, has a dependability value of around 40.703 m3
/s and for the Selindung River
in Pangkal Pinang City with an equatorial rainfall type and a watershed area of around 14 km2 has a
discharge dependability value of around 0.145 m3
/s. The rainfall intensity in each region strongly influences
the input discharge. Rain potential in each region can be utilized by storing the rain during the rainy season to
meet the demands of the surrounding community when the dry season arrives.