This research conducted in Opak River, in Yogyakarta. This river has broad (river flow area) 27,04 km2, and 20,11 km in length. The research objective is to make a planning about effective rainfall in 50 years and found the Opak Sand Pocket design. This research used methods with direct-survey in location, and collected secondary data from related agencies. From the data, it was obtained the value of precipitation the design, discharge flood design, dimensions of building hydrolic design (Main Dam, Sub Dam, Apron), and analysis the effectiveness of sand pocket in reducing the sediment that has happened. Based on the results of the research, discharge maximum ( Q50 ) that occurs in the river of 202,77 m3/s. So it can be calculated that sand pocket designed will have wide of apron 54,04 m, with total high of Main Dam 6 m, total high of Sub Dam 6 m, length of apron 10 m, thick of apron 0,96 m. Based on the ability of sand pocket in reducing the rate of the sediment that is happened, the building has effectiveness until 90,20 % in reducing bed load based on the calculation. Therefore, it can be argued that the building has been effective to reduce the speed of sediment occurring in Opak River.Penelitian dilakukan di Kali Opak, yang terletak di Yogyakarta. Kali Opak memiliki luas DAS 27,04 km2 , dengan panjang 20,11 km. Tujuan penelitian merencanakan besar curah hujan efektif 50 tahunan di Kali Opak dan menemukan desain Sand Pocket. Metode yang digunakan dalam penelitian adalah dengan melakukan survey langsung di lokasi, serta mengumpulkan data-data sekunder dari instansi terkait. Data-data tersebut kemudian diperoleh nilai curah hujan rancangan, debit banjir rancangan, dimensi desain hidrolis bangunan (Main Dam, Sub Dam, Apron, dan bangunan pelengkap), serta analisis efektifitas Sand Pocket dalam meredam laju sedimen yang terjadi.Berdasarkan hasil penelitian, diketahui debit maksimum (Q50) yang terjadi pada sungai tersebut sebesar 202,77 m3/s, maka dapat diketahui bahwa Sand Pocket yang direncanakan akan memiliki lebar pelimpah dengan dimensi 54,04 m, dengan tinggi total Main Dam sebesar 6 meter, tinggi total Sub Dam sebesar 4 meter, panjang Apron sepanjang 10 m, tebal 0,96 m. Bangunan tersebut cukup efektif untuk meredam laju dari sedimen yang terjadi pada Kali Opak dengan kemampuan Sand Pocket dalam mengurangi laju sedimen yang terjadi, diperoleh hasil perhitungan bahwa bangunan tersebut memiliki efektifitas hingga 90,20 % dalam mengurangi bed load.

Drainage functions to drain, deplete, remove or transport water. Generally, drainage is defined as a series of water facility used to reduce and/or remove excess water from an area or land, so that the land can be functioned optimally. Drainage is also realized as an effort to control the quality of groundwater in relation to salinity. The case study was carried on in Sekaran Village, Gunungpati District, Semarang City. The area size of Sekaran Village is 6,21 km². According to the writing method, the author used tools and materials required in this research. The tools used were a roll meter and Arcmap software as a medium for data-processing, and the materials taken was data regarding information about the condition of Sekaran Village in the extent of topographic maps, rainfall data. The method of data calculation used manual calculations in accordance with the rational method to figure out the rain discharge, and the manning formula for channel flowrate. The numbers of design rainfall for 5 years and 10 years was 169,365 mm and 171,502 mm; while the design discharge with return period of 5 and 10 years, for example, in channel 1 was branch 1 was of 0,6772 m³/s and the main channel was 5,7910 m³/s; The economic channel dimensions for the main channels 1 and 4 were the base width B = 1,596 m ≈ 1.6 m and the water height h = 0,796 m ≈ 8 0,8 m, the cross section was square.

Fire is a disaster that must be avoided in various ways, one of them is by using a fire extinguishing system to prevent fire disaster. This study used the Semarang City Health Office (DKK) Building as a sample. The purposes of this research were; (1) to find out whether the application of the fire protection system at DKK Building has met the regulations and (2) to determine whether the water distribution in the fire protection system in the Semarang DKK Building is functioning properly as needed. Data collection methods in this study consisted of observation and literature study. The observation was used to find research data in the form of planning drawings on the building protection system and the literature study was carried out to obtain data in the form of standard tool specifications and rules for using tools in the protection system. This study also used an analysis method based on an application program called Epanet 2.0. The Epanet program was used to simulate a hydraulic model according to the fire protection system at DKK Building. The results of the analysis using the Epanet 2.0 show that the sprinkler system has met the needs based on the amount of water supply discharge and based on the required pressure. The underground tank volume of 150 m3 has met the requirements based on SNI 03-3989-2000. The pressure value for all sprinklers has met the requirements of SNI 03-3989-2000 with the smallest pressure value is 2.5 kgf / cm2. The sprinkler system does not meet the water distribution value set in NFPA 13 with a maximum distribution time of 50 seconds while the analysis results show that the distribution time is 205 seconds. The pressure value at all points of the fire hydrant system meets the SNI 03-1745-2000 rules with a maximum value not exceeding 24.1 bars. The pressure value at the farthest hydrant box hose connection does not meet the SNI 03-1745-2000 rules with the pressure value at the farthest hydrant box is 4.6 bars, where is the minimum pressure is 6.9 bars.

Keruntuhan bangunan hidraulik check dam merupakan suatu fenomena keruntuhan bangunan hidraulik yang penting dikaji, khususnya ditinjau dari aspek-aspek hidraulik yang menyebabkan keruntuhan bangunan. Kajian keruntuhan bangunan Check dam dalam artikel ini mengambil kasus fenomena keruntuhan Bangunan Pengendali Sedimen (BPS) Kedung Ringin di wilayah Kabupaten Kebumen Provinsi Jawa Tengah Indonesia. Hasil-hasil penelitian menunjukkan bahwa keruntuhan bangunan tersebut dipicu sufosi dan boiling oleh rembesan di bawah spillway. Perbaikan keruntuhan bangunan tersebut harus dilakukan dengan mengganti seluruh bagian spillway dengan memasang material baru disertai pengawasan lebih ketat dalam pekerjaan pelaksanaan mengacu pada spesifikasi teknis yang ditetapkan. Diperlukan pula pemasangan turap di bawah spillway baru minimal sepanjang 4 m dari dasar spillway untuk mengantisipasi terjadinya sufosi di masa datang