GROUNDWATER POTENCY IN INDONESIA

Convention Bandung 2004 (CB2004)
The 33rd Annual Convention & Exhibition 2004

Indonesian Association of Geologist
Horizon Hotel, 29-30 Nov, 1 Oct 2004, Bandung

GROUNDWATER POTENCY IN
INDONESIA

Haryadi Tirtomihardjo

Abstract

In Indonesia, groundwater has a significant role in providing water for various
purposes, that is, drinking water in rural areas, drinking water and industry in
urban areas, and for irrigation supplement. A sustainable groundwater
utilization, hence, needs groundwater management with a proper manner. As
stipulated on paragraph 12 article (2) of Law No. 7 of 2004 on Water
Resources, “groundwater management is based upon the groundwater
basin”; that is, management should cover an area which is limited by
hydrogeologic boundaries, where the hydrogeologic events such as recharging,
flowing, and discharging of groundwater occur. It shows legally clarification on
shifting from management of wells (well management) to the management of
groundwater basins (groundwater basin management) which is aiming at the
conservation of groundwater.

In Indonesia has been identified 396 groundwater basins, mainly distributed in
the larger islands which have total groundwater potency about 638 milyard
m3/year. In Java and Madura islands, 80 groundwater basins were identified
which have total groundwater potency about 54 milyard m3/year. Various
extends of groundwater basin depending on the hydrogeologic conditions of the
area. Generally, at the larger islands such as Papua, Kalimantan, Sumatera,
and Java the groundwater basins are widely extended, while at the smaller
islands such as Nusa Tenggara and Maluku are relatively small extended.
Overlaying the groundwater basin and administrative boundaries of
kabupaten/kota shows four type of groundwater basins, i.e. groundwater basin
which are crossing province, kabupaten/kota, and state boundaries, as well as
groundwater basin which is fully in the kabupaten/kota boundaries.

Detail information on groundwater potency of each groundwater basin is
absolutely needed in order to establish the groundwater utilization plan. Such
information can be obtained by investigation which comprises study and
assessment on lateral and vertical boundaries of the groundwater basin,
configuration and parameter of aquifer systems, quantity and quality of
groundwater, recharge and discharge areas, and its degree of the groundwater
potency.

 

Abstrak

Di Indonesia, air tanah memegang peran penting sebagai air baku untuk
penyediaan air minum di daerah pedesaan, air minum dan industri di daerah
perkotaan, suplesi irigasi, dan sebagainya. Agar pemanfaatan air tanah untuk
berbagai keperluan itu dapat dijamin secara berkelanjutan diperlukan
pengelolaan air tanah secara benar. Pasal 12 ayat (2) Undang-Undang Nomor
7 Tahun 2004 tentang Sumber Daya Air menetapkan bahwa pengelolaan air
tanah didasarkan pada cekungan air tanah, yakni suatu wilayah yang dibatasi
oleh batas hidrogeologis, tempat semua kejadian hidrogeologis seperti proses
pengimbuhan, pengaliran, dan pelepasan air tanah berlangsung. Itu berarti
penegasan secara legal adanya perubahan paradigma dalam pengelolaan air
tanah, yang semula berdasarkan pengelolaan sumur (well management)
menjadi pengelolaan cekungan air tanah (groundwater basin management)
dengan tujuan konservasi air tanah.

Jumlah cekungan air tanah di Indonesia telah diidentifikasi sebanyak 396
cekungan air tanah, terutama tersebar di pulau-pulau besar dengan total
potensi mencapai sekitar 638 milyar m3/tahun. Sebanyak 80 cekungan air tanah
di antaranya terdapat di P. Jawa dan P. Madura dengan potensi air tanah
sekitar 54 milyar m3/tahun. Luas cekungan air tanah beragam tergantung
kepada kondisi hidrogeologis setempat. Umumnya di pulau-pulau besar seperti

P. Papua, P. Kalimantan, P. Sumatera, dan P. Jawa cukup luas, sedangkan di
pulau-pulau kecil seperti di Nusa Tenggara dan Maluku dijumpai cukup sempit.
Dikaitkan dengan batas wilayah kepamongprajaan, lamparan cekungan air
tanah sebagian bersifat lintas provinsi, lintas kabupaten/kota, lintas negara, dan
utuh berada dalam wilayah kabupaten/kota.
Sebagai dasar dan acuan dalam perencanaan pendayagunaan air tanah,
diperlukan informasi potensi setiap cekungan air tanah tersebut melalui
pengkajian secara rinci dan komprehensif yang mencakup penentuan sebaran
cekungan air tanah secara lateral dan vertikal, konfigurasi dan parameter
sistem akuifer, kuantitas dan kualitas air tanah, daerah imbuhan dan daerah
lepasan air tanah, serta tingkat potensi air tanah