American Society of Civil Engineers-EGS-IV International Conference on Environmental hydrology and Port Engineering, 2009 _________________________________________________________________________ HYDRAULIC PERFORMANCE OF INLAND PONDS CIRCULATION SYSTEMS Ashraf M. El-Moustafa 1 Mohamed H. Elgamal 2 Hesham Elbadry 3 Abstract Treatment of golf course ponds has recently received a lot of attention as a result of the vast recreational development in the Arab region. Generally these ponds experience some water deterioration problems. Accordingly developers usually use different treatment approaches including the chemical, surface circulation and aeration techniques. In this study, the surface circulation and the bottom aeration were investigated using two different hydrodynamic models. Two dimensional hydrodynamic model (RMA2) was used to study the ponds system under surface circulation technique while a well known CFD model “FLUENT” was used to investigate and study the bottom aeration technique. The results of the two models lead to the best arrangement to be implemented in the pond system to improve the pond water quality and to decrease or minimize the ponds deterioration. The study also concluded that the circulation technique will require high capital and operation cost while the bottom aeration techniques require lower capital and operation cost. More studies are required to better evaluate the two systems from the quality point of view where the water quality should be studied rather that the hydrodynamics only. Introduction Tourist and recreational related developments have expanded considerably in the whole Arab region especially in the last century as a result of gas price booming. Example of these developments includes the construction of recreational and/or tourist resorts that usually contain some attractive landscaping water-bodies such as closed ponds or a cascade of inland artificial lagoons. Golf Course ponds serve many purposes. They increase the added value of the project area and they work as water traps to golfers as they make golf courses more challenging which increases the popularity of the course and attracts more golfers to the project area. Golf course ponds work also as nutrient catchment basins. This is where the problems occur. Due to the necessity of high nitrogen and phosphorous fertilizers used to keep turf grass looking in good conditions; the ponds are the recipient of these nutrients and they could quickly start to grow algae and other invasive plants. 1 Assistant Professor Irrigation and Hydraulics Department - Faculty of Engineering – Ain Shams University. elmoustafa010@yahoo.co.uk 2 Assistant Professor Hydraulics Department - Faculty of Engineering – Cairo University 3 Associate Professor Irrigation and Hydraulics Department - Faculty of Engineering – Ain Shams University.