<p><strong>Abstrak</strong>. Indonesia memiliki potensi sumber daya air yang sangat besar, tetapi pemanfaatannya masih rendah, yaitu sekitar 20 persen dari potensi yang ada. Terdapat pengaruh negatif bila pemanfaatan air hanya sedikit, yaitu dapat mengakibatkan banjir dan longsor pada saat musim hujan serta kekeringan Musim Kemarau (MK). Tujuan dari penulisan ini adalah menyampaikan hasil kajian optimalisasi pemanfaatan sumber daya air untuk meningkatkan produksi pertanian yang dilakukan melalui  panen air dengan prinsip <em>eco-efficient </em> agar air tersedia sepanjang tahun dan berkelanjutan. Salah satu pemanfaatan sumberdaya air secara optimal adalah untuk meningkatkan produksi pertanian pada lahan sawah irigasi, lahan sawah tadah hujan dan lahan kering.  Implementasinya dilakukan dengan jalan meningkatkan ketersediaan air dan menerapkan efisiensi penggunaan air sehingga dapat memperpanjang masa tanam atau meningkatkan indeks pertanaman (IP) dan ekstensifikasi pertanian. Sampai saat ini, sudah cukup banyak infrastruktur air yakni embung, dam parit, dan<em> long storage </em>yang dibangun oleh Kementerian Pertanian. Disamping itu Kementerian PUPR dalam kurun waktu 2015-2019, telah menargetkan pembangunan 65 bendungan untuk mendukung ketahanan air dan ketahanan pangan. Secara keseluruhan saat ini terdapat 230 bendungan yang mencukupi bagi 11 persen layanan lahan irigasi seluas 7,2 juta ha.  Hal ini berarti, air irigasi dari bendungan dapat mengairi lahan sawah sepanjang tahun. Untuk mendukung optimalisasi sumber daya air, diperlukan ketersediaan air sepanjang tahun dan berkelanjutan. Pengelolaan sumber daya air harus dilakukan secara menyeluruh dari DAS tersebut, baik <em>blue water</em>  maupun <em>green water</em> dan pengelolaannya harus tepat yaitu menerapkan konservasi lahan dan air di hulu dan pendistribusian secara hemat dan adil. Optimalisasi penggunaan sumber daya air untuk pertanian bertujuan untuk meningkatkan produksi pertanian dengan tetap memperhatikan kelestarian lingkungan seperti menjaga ekosistem sungai tetap baik, mengantisipasi kerusakan sumber daya air dan memanfaatkan secara efisien tidak berlebihan.</p><p> </p><p><strong>Abstract</strong>. <em>Indonesia has a huge potential of water resources, but it is untapped efficiently with only around 20 percent utilized. There is a negative effect if only a small amount of water is used, which can result in floods and landslides during the rainy season and dry season dryness. The purpose of this paper is to deliver a study of optimizing the use of water resources to increase agricultural production carried out through water harvesting with the principle of eco-efficient so that water is available throughout the year and is sustainable. One of the optimal utilization of water resources is to use it for agricultural production in irrigated paddy fields, rainfed lowland and dry upland. It is implemented by increasing water availability and using water efficiently which is in turn it can extend the planting period or increase the cropping index and agricultural extensification. Recently, The Ministry of Agriculture has built adequate water management infrastructures such as reservoirs, ditch dams, and long storages. In addition, within the 2015-2019 periods, the Ministry of PUPR targeting the construction of 65 dams to support water and food security. There are currently 230 dams had been built which are sufficient to irrigate  11 percent of irrigated land or 7.2 millions hectares. This means that the water from dams can irrigate paddy fields continouosly throughout the year. To optimize the use of water resources, water availability is sustainably needed throughout the year. Water resources management must be carried out thoroughly within the watershed, both for blue water and green water. It must be precisely excetuted by implementing land and water conservation in upstream followed by distribution in an efficient and equitable manner. Optimizing the use of water resources for agriculture aims to increase agricultural production while still taking into account environmental sustainability such as maintaining a good river ecosystem, anticipating damage to water resources and utilizing efficiently not excessively</em><em>.</em></p>

Data dan informasi sumber daya air dalam suatu kawasan dapat digunakan sebagai dasar dalam menentukan teknologi pengelolaan air yang tepat sehingga dapat menjamin keberlanjutan ketersediaan sumber daya airnya. Teknologi pengelolaan air tersebut perlu diaplikasikan pada skala petani untuk menjawab permasalahan aktual di lapangan. Penelitian dilaksanakan di Provinsi Sulawesi Selatan pada bulan Januari sampai dengan Desember 2015 dengan tujuan untuk mengetahui ketersediaan dan kebutuhan air irigasi pada budidaya padi dan jagung di Provinsi Sulawesi Selatan. Penelitian dilaksanakan melalui beberapa tahapan yaitu: a) persiapan dan pengumpulan Peta Rupa Bumi Indonesia (RBI) dan peta sebaran daerah irigasi, b) survei dan pengumpulan data lapang, dan c) analisis data dan pemetaan. Ketersediaan air irigasi diketahui melalui pemodelan hidrologi menggunakan model Integrated Flood Analysis System (IFAS), sedangkan kebutuhan air ditentukan berdasarkan kebutuhan air tanaman padi dan jagung pada satu siklus pertanaman. Hasil penelitian menunjukkan bahwa Provinsi Sulawesi Selatan memiliki 4 golongan ketersediaan irigasi (1-4) dengan debit air antara <0,3 sampai >0,9 l dt-1 ha-1 , dan 4 indeks kecukupan irigasi A1 sampai A4, yaitu wilayah yang memiliki IP (indeks pertanaman) 300 dengan pola tanam berturut-turut padi-padi-padi; padi-padi-palawija; padi-palawija-palawija; dan palawija-palawija-palawija. Studi kasus di lima kabupaten yaitu: Gowa, Jeneponto, Kota Makasar, Maros dan Takalar menunjukkan bahwa di kelima kabupaten tersebut dengan 31 kecamatan memiliki indeks kecukupan irigasi A1. Ini berarti bahwa di semua kabupaten dan kecamatan areal penelitian ini dapat diterapkan pola tanam padi-padi-padi.

Development of Rainfall and Runoff Harvesting Technology: Farming System Analysis of Water Resources Utilization.Application of rainfall and runoff harvesting in dry land could be increasing the availability of water resources, extending the growing season, and reducing the risk of loss yield. To create a sustainable water management, farmers participation were needed in its management. The objectives of the research were to study the impact of rainfall and runoff harvesting technology applications (channel reservoir) on farming system and to study the farmers perception on the existence of channel reservoir.The study was conducted in Limampoccoe village, Cenranae subdistrict, Maros distrisct, South Sulawesi province, from February to October 2012. The research was conducted by several steps namely: 1) the application of rainfall and runoff harvesting technology through channel reservoir, 2) analysis of the farming system and assessment of the farmer perception on the existence of channel reservoir. Result of the research showed that rainfall and runoff harvesting technology have been increasing the cropping intensity by changing the previous cropping pattern from rice-fallow-fallow into ricepeanuts-fallow and rice-watermelon-fallow. There was an increase in farmers' income after channel reservoir built and the farmers will be taken the responsibility to maintain the continuity of the channel reservoirs function. Keywords: rainfall and runoff harvesting, cropping intensity, farmers' income ABSTRAKAplikasi teknologi panen hujan dan aliran permukaan di lahan kering dapat meningkatkan ketersediaan air, memperpanjang masa tanam, dan menekan risiko kehilangan hasil. Untuk menciptakan pengelolaan air berkelanjutan harus didukung peran serta masyarakat/petani dalam pengelolaannya. Penelitian ini bertujuan untuk mempelajari dampak aplikasi teknologi panen hujan (dam parit) terhadap usahatani dan melihat persepsi masyarakat terhadap keberadaan dam parit. Penelitian dilakukan di Desa Limampoccoe, Kecamatan Cenranae, Kabupaten Maros, Provinsi Sulawesi Selatan, pada bulan Pebruari sampai Oktober 2012. Kegiatan dilaksanakan melalui: 1) aplikasi pembangunan teknologi panen hujan dan aliran permukaan melalui dam parit, 2) analisis usahatani dan penilaian persepsi masyarakat terhadap keberadaan dam parit. Hasil penelitian menunjukkan bahwa teknologi panen hujan dan aliran permukaan dapat meningkatkan intensitas tanam dari pola tanam padi-bera-bera menjadi padi-kacang tanahbera dan padi-semangka-bera, dengan demikian terdapat peningkatan pendapatan usahatani setelah pembangunan dam parit. Petani merasakan manfaat dam parit dan merasa bertanggung jawab dalam menjaga kelangsungan fungsi dam parit. Kata kunci: teknologi panen hujan, aliran permukaan, indeks pertanaman, pendapatan usahatani

Provision of agricultural land to support food security has criteria including optimal crop productivity, adequate intensity, guaranteed water availability (surface water and groundwater) and environmental conditions that are secured to damage (conservation). Food estate in Central Kalimantan will be allocated 30,000 ha or 300 km2 in 2020. Since the land allocation for food estate are existed near main rivers, environmental aspect from hydrological issue becomes one major aspect that must be considered. This study assesses potential rice field by using GIS and two dimensional unsteady hydrological model simulation due to flood prone area. Based on this model, vulnerable area could be measured by quantitative method in order to prevent losses act. The results show where composition of existing land use in upstream of each watershed (Barito, Kahayan, Kapuas River Basin) give different maximum peak discharge based on hydrograph curve of each zone of food estate area targeted. Food estate of 30,000 ha overall has less index of vulnerability of flood hazard, where 9% of its total area inundated by Q50 years return period discharge.

Polder system is the key to manage floods in agricultural non-tidal swamp land. Infrastructures to support polder system integrated management include: regional drainage systems, retention ponds, dikes, pumps and/or gates. Pump requirement in an optimally managed polder system is influenced by the polder area, rainfall, soil, and hydrological characteristic. This article presents water balance models application in determining the number and operational duration of pumps to achieve effective and optimal polder function in controlling floods and inundation during the rainy season. This study was conducted in a palm-oil plantation located in lebak swamp area in Pawalutan, Banjang, Hulu Sungai Utara, during September 2016 to September 2017. Pump units and operation durations were calculated based on estimated inundation volumes depending on the water inlet and water balance. Seepage discharge was estimated using Darcy equation. Result of the recovery test measurements showed hydraulic conductivity value of 4.1x10−05 ms−1, while the estimated seepage discharge was 8.6 m3 hr−1 km−1. The pump requirement analysis indicated the need of 55 pump units with 2,500 m3 hr−1 pumping capacity to overcome inundation in the study site with 1,417 ha inundated area. These pumps were distributed into 9 zones, each with 4 to 10 units.