Introducing a New Dam-Type Sediment Excluder Method at Dam Reservoirs for Sediment Mitigation

Document Type : Research Article


1 MSc. Graduate of Water Structures Engineering, Water Engineering Department, Shiraz University, Shiraz, Iran

2 Professor of Water Engineering, Department, Shiraz University, Shiraz, Iran


In this paper a new method for mitigation of dam reservoirs sedimentation is introduced and its performance is evaluated. This method includes a self-cleaning and permanent function structure resembling a short dam built across the rivers discharging into the dam reservoir. This structure, called Dam-Type Sediment Excluder (DTSE), extracts suspended sediment from flows upstream of reservoir through a middle opening (gate) and prevents entrance of sediments into the reservoir. In this study, using laboratory experiments, the efficiency of the proposed DTSE method was examined under three ratios input discharges, three middle opening relative heights and the output (bypass) to input flow rates of 0.1, 0.2 and 0.3. The results showed that: 1) the efficiency of the DTSE increased with increase of middle opening height, 2) increase of bypass flow ratio affects the model efficiency and sediment concentration of bypass flow in a positive and negative manner, respectively. Therefore, between three flow ratios, bypass flow ratio of 0.2 is the optimum one, due to the water loss of 20% and proper efficiency, 3) the maximum extraction efficiency of the model was found to be about 40% while the average optimal efficiency, for bypass flow ratio of 0.2, was about 26%. Therefore, the new DTSE method could be introduced as an effective method for sediment mitigation, in comparison to other reservoirs sedimentation mitigation methods such as density current venting with only 20% efficiency.


ایمان‏شعار، ف.، حسن‏زاده، ی.، اعلمی، م. ت. و داننده مهر، ع.، (1392). "تحلیل عدم قطعیت در تعیین جرم مخصوص رسوبات ته‏نشین شده در مخازن سدها"، نشریه آب و خاک، جلد 23 شماره 1، . ص. 27 -37.
بی‏نام، سیستم شناسنامه ملی سدهای ایران، شرکت مدیریت منابع آب ایران، (
سیدی، ح.، (1387)."ارائه روش جدید جداسازی رسوبات از آب بالادست سدهای انحرافی"، پایان‏نامه کارشناسی ارشد، دانشگاه شیراز، شیراز.
Annandale, G.W., (1987). Reservoir Sedimentation. Elsevier Science Publishers, New York.
Fan. J., (1986). “Turbid density currents in reservoirs”, Water International, 11 (3), pp. 107-116.
Heede, B.H., (1976). “Gully development and control: the status of our knowledge”, USDA Forest Service Research Paper RM-169, Rocky Mountain Forest and Range Experiment Station, Fort Collins, Colo.
Hwang, J.S., (1985). “The study and planning of reservoir desilting in Taiwan”, Water International, 10 (1), pp. 7-13.
Imanshoar, F., Hassanzadeh, Y. and Aalami, M.T., (2009). “An introduction to environmental impacts of sedimentation and erosion due to dam’s construction”, Workshop on Reservoir Sedimentation Control, Regional Centre on Urban Flood Management, Karaj, Iran.
Jacobsen, T., (2009). “Some aspects of reservoir sedimentation, Workshop on Reservoir Sedimentation Control”, Regional Centre on Urban Flood Management, Karaj, Iran.
Meshkati Shahmirzadi, M.E., Dehghani, A.A., Sumi, T., Naser, Gh. and Ahadpour, A., (2010), “Experimental investigation of local half-cone scouring against dam”, River Flow 2010.
Talebbeydokhti, N. and Naghshineh, A, (2004). “Flushing sediment through reservoirs”, Iranian Journal of Science & Technology Transaction B 28, pp. 119-136.
Tolouie, E., (1993). “Reservoir sedimentation and de-siltation”, Ph.D. Thesis, U. Birmingham, U.K.
van Rijn L.C. (1993). Principles of sediment transport in rivers, estuaries and costal seas. Published by Aqua publication, Amsterdam, pp. 7-51.
Verstraeten, G., Poesen, J., Vente, J. and Koninckx, X., (2003). “Sediment yield variability in Spain: A quantitative and semi-qualitative analysis using reservoir sedimentation rates”, Journal of Geomorphology, Vol. 50, Issue 4, pp. 327-348.
White, R., (2001). Evacuation of sediments from reservoirs, Thomas Telford Publishing, London, p. 280.
Wu, C.M., (1991). “Reservoir capacity preserving practice in Taiwan”, Proc. 5th Federal Interagency Sedimentation Conf., Las Vegas, pp. 10.75-10.81,
Zhaoyin, W. and Chunhong, H., (2009). “Strategies for managing reservoir sedimentation”, International Journal of Sediment Research, Vol. 24, No. 4, pp. 369–384 (in Chinese).