Perencanaan Bangunan Pengendali Sedimen Daerah Aliran Sungai Kreo Kota Semarang

Kreo River is the part of Garang River which located in Semarang City and the area of this river is 61,059 km2. Kreo River is one of sedimentation contributor for Jatibarang Dam, an estimated 387,33 Ton/Ha/Years sedimentation which enter in Jatibarang Dam are come from this river. One of the solution for the sedimentation and erosion problem in river is by developing building controller sedimentation or similar called check dam. From the calculation, check dam planned to have physical like as follows : the peak elevation of spillway main dam in the elevation + 187,419 m with highly effective is 4 m and deepness of foundation is 2 m, wide of spillway main dam obtained 45 m, with Q plan return period 100 years to 216,475 m3/s, high of wings main dam is 3 m at elevation + 190,419 m with highly of surveillance is 0,8 m, main dam construction use rubble stone masonry, elevation of peak spillway sub at + 185,419 m with highly obtained 2 m and deepness foundation until 2 m, sub dam construction use rubble stone masonry, the elevation of protection floor at +183,419 m with thickness until 1 m, the construction use rubble stone masonry

Perencanaan Perlindungan Pantai Sayung Demak

Sayung shore in Demak is one of many shores that its coastline has been receded quite alarming. Bedono village have the worst damage, now just five of seven hamlets exist in Bedono. Senik and Tambaksari are two retreat hamlets due to erosion. Moreover, the access roads among those hamlets were disconnected, and the sea water had flooded the settlement residence. From the years of 2000-2005, 325 Ha fish ponds were lost due to the erosion, and 110 Ha were flooded by the tide.The objective of this study is to plan Sayung shore protection. Location of the study is on western side of Sayung river with the length of coastline around 3.9 kms.The aspects of analysis are tidal currents, wave generated by wind, coastal morphology, and geological engineering. There are four alternatives of shore protections which are breakwater, revetment, groin and combinations.Combination of revetment and breakwater were analysed against coastal morphology, function, low cost structure, and workability. Revetment along the 2.3 kms will be built on the western side, and on the eastern side three units of breakwater, which each breakwater length is 100 m with 40 m breakwater gap

Perencanaan Sistem Polder Kota Lama Semarang

Kota Lama Semarang was an area where had land subsidence ± 5 cm/year. It made the land surface elevation of Kota Lama Semarang is lower than sea water level and river water levels. It made flood and tidal flood happened in Kota Lama Semarang. The problem was treated by applying polders system drainage (non-gravity systems). The Final report aimed to protect Kota Lama Semarang from flooding by applying design polder system with its components, namely: retention ponds, primary canals, pumping stations, discharge channels, and dikes. The methods included: field surveys, problem identification, problem definition, literature review, data collection, analysis of hydrological data, technical for all components, the calculation of project cost and the time schedule, the stage of the Work Plan and Technical Requirements, and manufacturing method of the project.The polder system is planned retention pond for 18363.25 m3 capacity, 6105 meters of primary channels using precast, three pumps with each pump has 0.5 m3 capacity, 550 m of long exhaust duct using steel pipes, and 30 cm of highly the elevation road that used as embankment on Parks Tawang st., Peacock st., Cenderawasih st., Tantular masters st., Sendowo st., and KH. Agus Salim st. The cost to build this polder system is Rp 34,858,000,000.00. In the construction, it have to be known time schedule and traffic management, because the area has densely residential areas and has enough traffic flow congested. Beside of calculating the technical, it is needed to socialize with local citizen in order to participate in the maintenance of all components of the system so the polder system drainage can be used optimally and persist throughout the life of the plan