Open Journal of Modern Hydrology, 2014, 4, 164-172 Published Online October 2014 in SciRes. http://www.scirp.org/journal/ojmh http://dx.doi.org/10.4236/ojmh.2014.44016 How to cite this paper: Wahono, E.P., Legono, D., Istiarto and Yulistiyanto, B. (2014) Environmental Flow Assessment Using Water-Sediment Approach at the Sekampung River, Indonesia. Open Journal of Modern Hydrology, 4, 164-172. http://dx.doi.org/10.4236/ojmh.2014.44016 Environmental Flow Assessment Using Water-Sediment Approach at the Sekampung River, Indonesia Endro Prasetyo Wahono 1,2* , Djoko Legono 2 , Istiarto 2 , Bambang Yulistiyanto 2 1 Department of Civil Engineering, The University of Lampung, Bandar Lampung, Indonesia 2 Department of Civil and Environmental Engineering, Universitas Gadjah Mada, Yogyakarta, Indonesia Email: * epwahono@eng.unila.ac.id Received 11 August 2014; revised 11 September 2014; accepted 9 October 2014 Copyright © 2014 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract Environmental issue has been considered more significant in many aspects of engineering deci- sion-making process particularly in river management. There is an increasing effort to conserve functioning of rivers for human use as well as nature, therefore environmental flow assessment has been widely developed. This paper discusses on environmental flow assessment of the Sekam- pung River, particularly on its middle reach. A new analytical approach based on water-sediment equations was introduced in order to determine a minimum environmental flow at the certain cross section of a river. The result of the new method was then compared with a minimum envi- ronmental flow provided by using two hydrological based methods, namely, Tennant and Flow Duration Curve Analysis (FDCA) method. The result shows that the concerned discharge provided by the water-sediment method (3.5 m 3 /s) is the smallest compare with a minimum environmental flow that is provided by both Tennant (5.7 m 3 /s) and FDCA method (4.5 m 3 /s). It is promising that the water-sediment method can be used as a simple approach on preliminary state of environ- mental flow assessment. The method involves not only water discharge but also its related sedi- ment flow of the river in order to mitigate further ecological and morphological risks. Keywords Water-Sediment, Environmental Flow, River Morphology 1. Introduction In the recent years, environmental issue has been considered more significant in many aspects of engineering * Corresponding author.