Measuring Capabilities Kaligarang
December 21, 2016 By Arief Khristanto

Semarang as a metropolitan city not only save fanfare but also a variety of learning management of the urban environment. Call it rob, floods, ground subsidence, erosion, sanitation, to the management of water resources. Kaligarang including watershed management, one of the rivers in Semarang which is the source of raw water for PDAM Tirta installation Moedal Semarang.

The river is part of the three main rivers in the Watershed (DAS) Garang, along with Kali (river) chips and Kreo. The first intervention against Kaligarang occurred in the Dutch East Indies through the construction of weirs Simongan and West Banjirkanal 1300s. At that time, Kaligarang functioned as flood control system. After Indonesian independence, the river will get an additional function as a raw material source of drinking water.

It was marked by the construction of the Water Treatment Plant (IPA) Kaligarang I in 1959. The plan has no synergy with the pattern of regional development, both in Semarang and in the District of Semarang and Kendal. The pattern of regional development also makes Kaligarang as drainage systems, both of settlements and industries along the flow of the rivers in the watershed Garang.

1990 is a milestone that re-awaken the citizens will be the role and functions of flood control Kaligarang as given in the big flood. The flash floods were not the first time because it also occurred in 1963, 1990, 2000, 2002, 1990 and 2008. However, the incidence of the most impression on the memory of the citizens.

Year 2010-2013 realization of normalization and development projects Banjirkanal West in anticipation of flooding. The canal was designed to be appointed or comfort, and a number of activities were held in a public area of ​​the region. Major waterways DAS Garang (Kali Garang, chips, and Kreo) in the spatial planning in the three areas have local protection areas such as riverbanks.

How effective are the spatial patterns in protecting the health of the river? Banks of three main rivers are still free from the designation should not be. But the conditions Kaligarang diminishing, particularly related to water quality. There are several factors that cause it to happen.

First; streams creeks DAS Garang still got a load of pollution that continues from the activities of domestic, industrial or agricultural use. The entire pollution load that accumulates in the main rivers, namely Kaligarang.

High sedimentation

Second; yet teratasinya erosion problems due to the opening of the land so that high sedimentation in the river was not resolved. Deposition in the water bodies tend to increase every year. Third; river normalization is done by cleaning streams from small to large rocks reduce power recovered Kaligarang.

Fourth; Kaligarang downstream conditions were inclined ramps also hinder the process flow required in the recovery of the river. In fact, at some point, especially in the dry season, the river had become anoxic or have a very small oxygen content.

New challenges, how clean water for residents of Semarang still be fulfilled from Kaligarang. Approximately 60% of residents of Semarang is now dependent on the fulfillment of taps as a source of clean water. In the last 5 years, increasingly frequent water flowing to the consumer is not as expected, sometimes even halted.

The end of the dry season in 2014, for example, is the culmination Kaligarang water conditions were very bad due to the oxygen content is very small, far below the standards of water sources. The peak of the rainy season also gives a challenge for treating drinking water because the river water was very turbid due to sedimentation.

The public need for clean water is the main thing that must be guaranteed by the government. Kaligarang is the largest supplier of raw water for PDAM Tirta Moedal Semarang. With the increasing degradation of the condition of the river was still mampukah to meet the needs of clean water for the citizens? (10)

– Arief Khristanto SHut, Director of the Foundation Bintari