Abstract—Lakes in Universitas Indonesia (UI) have several problems to overcome. Water quality of UI’s lakes degrades in the last decade. One of the problems is high turbidity. The longer turbidity in lakes, the more dangerous the lakes environment life would be. So, this research focuses on sediments problem or physical assessment. The main research aims to develop hydrodynamic and sediment transport modelling of Agathis and Mahoni Lakes in Universitas Indonesia. The authors want to increase the quality of water in UI’s lakes and make both Agathis and Mahoni Lakes as the representative preliminary model. Research design or methodology is needed to concept the research to achieve goals. Unfortunately, research methodology has not been developed yet for this case. This paper goals to construct methodology as a preliminary study of the main research. The authors use extensive literature review to model novel methodology. Hydrodynamic and sediment transport modelling could be modelled by Resources Modelling Associates (RMA). Hydrodynamic phenomena in fluid and sediment transport modelling have the suitable governing equation concept with RMA’s governing equation. As a thinking result, the main research would be conducted by RMA program modelling, field sampling, and laboratory testing. Field sampling and laboratory could figure the amount of sediment concentration in lakes as data input. The final simulation of this following research is making sensitivity and scenario analysis to prove several hypotheses. Index Terms—Hydrodynamic modelling, RMA program, sediment transport. I. INTRODUCTION Lakes are life, so their existences are important to notice. Lakes include raw water resources category [1]. The quality of raw water is a critical indicator for environment [2], [3]. However, people today have less water for themselves, livestock, and plants. Raw water is two percent of earth’s groundwater [4]. In addition, it is the most decreasing and changing ecosystem [5]. Lakes ecosystem consists of physical, chemical, and biological characteristics in the water body. The interaction among them could be studied, understood, and used for effective lakes management [1]. Recent days, the effort to do lakes conservation is difficult Manuscript received November 20, 2017; revised December 20, 2017. This work was supported by Indonesia Endowment Fund for Education or Lembaga Pengelola Dana Pendidikan (LPDP) under LPDP Research Grant. This organization is under The Ministry of Finance of Indonesia. Rian Mantasa Salve Prastica is with Civil Engineering Department of Engineering Faculty, Universitas Indonesia, Depok, West Java, 16424, Indonesia (e-mail: rianmantasasp@gmail.com, rian.mantasa@ui.ac.id). Herr Soeryantono and Dwinanti Rika Marthanty are with Water Resources Management Group, Civil Engineering Department, Faculty of Engineering, Universitas Indonesia, Depok, West Java, 16424, Indonesia (e-mail: herrsoeryantono@ui.ac.id). to do for several reasons. The threat of biodiversity decreasing in raw water ecosystem could be affected from various factors: uncontrollable exploitation, water pollution, stream modification, damage habitat, and exotic species invasion [6]-[9]. Environment changes globally. Nitrogen deposition, temperature increasing, and rainfall pattern changes are supportive factors for environment threat [10], [11]. In the past years, people controlled water through on-stream approach. They regulated rivers. Today, off-stream approach usage is highly increasing. This approach involves retention pond and infiltration wells. Jakarta has been implemented the on-stream approach to regulate its water. The Jakarta’s government constructs lakes system. So does Depok’s government. There are hundreds of lakes in both Jakarta and Depok regions. These lakes could have optimum hydrological function if they are preserved. But, the society paradigm becomes a barrier. The lakes become garbage and waste water dumping site. Furthermore, they give negative effects, for examples, creating living habitat for mosquitos, becoming water-borne diseases trigger, and producing bad odor. To increase the land value, the society prefer to hoard the lakes with soil. The example is Pedongkelan Lake that is located in Jakarta-Depok boundary. Its water body area is decreasing because of land filling in the lake. Developing Hydrodynamic and Sediment Transport Modelling on Lakes: A Preliminary Study Rian Mantasa Salve Prastica, Herr Soeryantono, and Dwinanti Rika Marthanty International Journal of Environmental Science and Development, Vol. 9, No. 3, March 2018 49 doi: 10.18178/ijesd.2018.9.3.1072 Universitas Indonesia (UI), which is located in Depok, West Java, has started to increase the effort of making better water quality. UI has six lakes, namely Kenanga, Agathis, Mahoni, Puspa, Ulin, and Salam lakes. UI as educational institution should become role model to manage healthy lake to the students and society. However, UI’s lakes quality is deteriorating in the last five years. UI plans several systems: debris removal, sediments removal, and nutrients removal. These efforts are highly suggested to be conducted, so the lakes could perform well in hydrological function. These could affect to restore water quality and biotic life. This proposed problem needs a model simulation to do water resources management effectively and efficiently. Several simulators have been examined, for example, phosphorous and nitrogen distribution simulator. However, sediment distribution simulator is not developed and technologically advanced yet. The simulator could be modelled for hydrodynamic and sediment transport. Hydrodynamic and sediment transport models could be used as water quality model for lakes ecosystem response to various change or condition. According to these general problems, a solution is needed to make lakes or ponds become physically, chemically, and biologically sanitary. This research aims to find a