Analisis Ketersediaan, Kebutuhan dan Kualitas Air Pada DAS Batang Merao - Sri Rahayu Ningsih; Eri Gas Ekaputra; Fadjar Goembira (School of Postgraduate Studies, Diponegoro Univer, 2020)
Sungai Batang Merao dimanfaatkan sebagai sumber air baku air bersih PDAM, sumber energi alternatif PLTMH, sumber air irigasi dan kebutuhan masyarakat sehari-hari di Kabupaten Kerinci dan Kota Sungai Penuh. Terganggunya kawasan hulu DAS berdampak terhadap pasokan dan kualitas air ke daerah tengah dan hilir. Ketebatasan ketersediaan air bersih dan penurunan kualitas air antara lain disebabkan oleh adanya kegiatan penambangan pasir dan batu di kawasan hulu, terjadinya konversi lahan dari lahan pertanian menjadi lahan terbangun terutama di daerah bantaran dan sempadan sungai serta pemanfaatan sungai sebagai tempat pembuangan limbah cair domestik dan peternakaan. Metode yang digunakan dalam penelitian ini bersifat deskriptif kuantitatif. Analisis ketersediaan air menggunakan metode debit andalan (Q80) dan kebutuhan air dihitung berdasarkan kebutuhan air pada sektor domestik, non domestik, pertanian, peternakan dan perikanan. Analisis status mutu air menggunakan metode indeks pencemaran (IP) untuk melihat kondisi kualitas air Sungai Batang Merao sesuai dengan KepmenLH Nomor 115 Tahun 2003. Berdasarkan hasil penelitian menunjukkan ketersediaan air DAS Batang Merao adalah sebesar 22.70 m3/detik dan total kebutuhan sebesar 26.71 m3/detik. Status mutu air Sungai Batang Merao berdasarkan nilai indeks pencemaran (IP) berada dalam kondisi tercemar ringan dengan kisaran nilai indeks 2,41 – 6,43 berdasarkan baku mutu air kelas II PP No. 82 Tahun 2001 dengan parameter TSS, BOD, COD, T-Pospat, Nitirit, Minyak dan Lemak serta MBAS melebihi nilai baku mutu. Berdasarkan hal tersebut dapat disimpulkan bahwa kualitas air Sungai Batang Merao tidak layak untuk dikonsumsi dan tidak seusi dengan peruntukannya sebagai sumber air baku air bersih. Ketersediaan sumber daya air DAS Batang Merao tidak dapat memenuhi kebutuhan air masyarakat pada DAS Batang Merao dengan neraca air dalam kondisi defisit sebesar 4.01 m3/detik.ABSTRACTThe Batang Merao River is used as a source of raw water for PDAM, an alternative energy source for PLTMH, a source of irrigation water and daily needs of the people in Kerinci Regency and Sungai Penuh City. The disruption of the upstream watershed area has an impact on the supply and water quality to the middle and downstream areas. Limited availability of clean water and a decrease in water quality are due to, among others, sand and rock mining activities in the upstream area, the conversion of land from agricultural land to developed land, especially in riverbanks and river boundaries and the use of rivers as a place for disposal of domestic liquid waste and livestock. The method used in this research is descriptive quantitative. Analysis of water availability uses the reliable discharge method (Q80) and water needs are calculated based on water needs in the domestic, non-domestic, agriculture, livestock and fisheries sectors. Analysis of water quality status using the pollution index (IP) method to see the condition of the water quality of the Batang Merao River in accordance with KepmenLH No. 115/2003. Based on the results of the study, the availability of water in the Batang Merao watershed is 22.70 m3/second and the total demand is 26,71 m3/second. The status of the Batang Merao River water quality based on the value of the pollution index (IP) is in a lightly polluted condition with an index value range of 2,41 – 6,43 based on class II water quality standards PP No. 82/2001 with parameters TSS, BOD, COD, T-Pospat, Nitrite, Oil and Fat and MBAS exceeding the quality standard value. Based on this, it can be concluded that the water quality of the Batang Merao River is not suitable for consumption and is not compatible with its designation as a source of raw water. The availability of water resources in the Batang Merao watershed cannot meet the water needs of the community in the Batang Merao watershed with the water balance in a deficit of 4,01 m3/second.