Most of the population in Indonesia uses groundwater to meet the need for clean water. With the rapid population growth, there has been an increase in the conversion of open space land into residential, offices, and commercial areas. The land conversion increases the impervious surface throughout the city and could impact the availability of clean water in the future. Implementation of water conservation is needed to ensure long term availability of clean water. Rainwater harvesting systems are one of the methods to utilize rainwater as an alternate clean water source and water conservation. This study aims to calculate the volume of rainwater harvested in mall building in South Tangerang using EPA-SWMM to design a rainwater reservoir. The result of this study is an average of 80 m3/day of rainwater harvested from mall building in South Tangerang. The design for the reservoir is rectangular with dimensions of H 4 m × W 18.3 m × W 6.5 m and a capacity of 476.06 m3.

The rapid development of the construction world in Indonesia raises the need for more effective supporting technologies. One example of technology support in the construction world is the application of Building Information Modelling. With this background, the research was made using the implementation of BIM on a project, in order to increase the digitization of the construction world in the future. By using various BIM software such as Allplan engineer, Allplan Bridge, Openroads Bentley, and Synchro. The result is that the alternative bridge design is declared feasible because there are no conflicts in the superposition analysis with the BIM software approach, interviews with experts and BINA MARGA criteria. After the application of the BIM Software, the results shows there is an increase of for the volume of concrete material, volume of reinforcement weight, and the cost, this is caused by a more accurate design for the model.

Weir is a building that is formed to change the nature of river flow to accommodate irrigation needs. The main purpose of a weir is to raise the river water level, drain the channel through the intake channel, allow water to be tapped, control all flow, etc. If a flow experiences a large shock, it will cause a hydraulic jump resulting in a transition of flow from supercritical to subcritical. The analysis can be performed, it was done using the Computational Fluids Dynamics (CFD) software, FLOW-3D. To model the 3-D weir used in this FLOW-3d, AutoCAD is used and finally, Flow Sight will be used to display visualization results such as graphics and videos. This paper investigates the Froude number and depth-averaged velocity on the trapezoidal weir. Moreover, the numerical modelling of trapezoidal weirs has been compared with the experimental result and numerical modelling of other types of weirs. The results show that the Froude number is proportional to the average velocity of this depth because the Froude number increases with the increase in the average velocity. There is a difference with the flow that flows after the weir, in a trapezoidal weir the Froude number decrease slightly but after that, it increases again downstream.

Indonesia location is geographically very strategic for trade since it is located between two continents and two oceans. This condition must be supported by inter-island transportation facilities and infrastructure, including proper harbors. The ongoing construction of Tourism Harbor at South Eastern Bali must have satisfactory stability as an initial survey shows high passenger traffic. The tourism Harbor will connect the hinterland to the Nusa Penida Islands, specifically Sampalan, Buyuk, Toya Pakeh, Jungut Batu, Tanjung Sanghyang, and Munjul Bias.Therefore, analysis of piles subjected to lateral forces is critical to ensuring the stability and serviceability of a jetty structure. This study aims to investigate the structural stability of Tourism Harbor by analyzing the deflection of the pile with configurations such as pile diameter (35 cm, 45 cm, and 60 cm), pile materials (concrete pile and steel pile), and the berthing force caused by two types of passenger ships (Bounty Cruise and Bali Hai II) under extreme condition of HWS (2.6 m). The analysis results indicate that an insignificant deflection can be obtained by using a large diameter pile and installing steel piles.