Groundwater Utilization Policy Strategy as Sustainable Source of Water Supply in Semarang City.

Abstract

Semarang as the capital of Central Java province and a metropolitan city exploits increasing ground water. The volume of groundwater that was taken in 2004 is 6.3 x 106 m3, and in 2008 it was 9.6 x 106 m3. There are three sectors in the utilization of groundwater in the which, is domestic, industry, and hotel. 56,1% of domestic water needs are supplied by PDAM Tirta Moedal, which takes 19% of groundwater. Meanwhile, industries and hotels take 90% of groundwater. As the utilization of groundwater in the city in 2008 reached 5.59 x 106 m3, it will experience groundwater deficit in 2030. To anticipate the deficit, eight are proposed, namely (a) limiting the growth rate of the hotel to 1% per year and reducing water consumption of hotel guest to 120 L/person/day, (b) limiting industrial growth rate to 6% per year to 3% per year, (c) reducing the domestic water consumption by limiting population growth to 1% per year and reducing water consumption to 120 L/person/day, (d) increasing capacity of PDAM to supply 70% of domestic sector need, while limiting ground water uptake to 15%, (e) a combination of scenarios a and b, (f) a combination of scenarios a, b, and c, (g) a combination of a, b, c, and d, and (h ) moratorium on utilization of groundwater. However there are two applicable scenarios. (1) scenario (g) to reach 6.97 x 106 m3 groundwater availability in 2050 without groundwater deficit (2) moratorium as the use of groundwater to reach 13.33 x 106 m3 groundwater available in 2050 with 15,82 meters MAT, as the availability of groundwater will uncreased in 2020, and it will achieve safety level in 2030. The value of groundwater at present is Rp. 229 514 063, - while in 2050 with a discount rate of 10%, it is Rp. 335 343 581 206, -. The institutions serve as enforcers of conservation of groundwater utilization are the government of Semarang, the Office of Energy and Mineral Resources, and PDAM, while the activators are the industry and hotels.

Pemanfaatan air sebagai sumber air bersih telah diatur dalam Undangundang No. 7 tahun 2004 yaitu tentang sumberdaya air, sedangkan pemanfaatan air tanah khususnya air tanah dalam (confined aquifer) sebagai sumber air bersih telah diatur melalui Peraturan Pemerintah No. 43 tahun 2008 tentang air tanah. Kebutuhan air bersih untuk air minum dan rumah tangga di Kota Semarang pada tahun 2008 dengan jumlah penduduk 1.481.644 jiwa adalah 222,25 x 106 liter/hari atau 80,0 x 106 m³/tahun. Apabila dari jumlah tersebut sekitar 80% memanfaatkan air tanah maka jumlah air tanah yang disadap untuk kebutuhan ini sekitar 64,0 x 106 m³/tahun. Pemakaian air tanah untuk keperluan industri dan usaha komersial melalui sumur bor yang berlokasi di kota Semarang selalu meningkat setiap tahun, yaitu pada tahun 2003 dari 543 sumur bor pengambilannya tercatat 15,31 x 106 m3, dan pada tahun 2006 volume pengambilan menjadi 20,98 x 106 m3 melalui 680 sumur bor.