Slow sand filtration is a simple technology to purify water. Despite being a well-known technique, most of the constructed slow sand filter reduce their removal efficiency within short period of time. The objective of this study is to design high performing slow sand filter by changing the depth of sand. Pilot slow sand filter was fabricated and filled with sand at different depths. The raw water drops down over the sand. Water quality parameter like turbidity was measured for both filtered and raw water using turbidimeters. The designed filter has a removal efficiency of 84 % for turbidity and 57% for total dissolved solid at 80 cm sand bed depth, and 69 % removal of suspended solid occurred at depth 50cm. The removal of suspended solid is effective at 50cm sand bed depth and for turbidity and total dissolved solid are effective at 80 cm sand bed depth. Slow sand filter has an effective water treatment method for low turbidity surface water. However, at larger turbid water, the removal efficacy was significantly decreased. Therefore, for larger removal efficiency, slow sand filter is recommended for low turbid water. For larger turbid water, the slow sand filter needs additional pretreatment systems to increase their clogging time. Key words: Godey town, Pilot scale slow sand filter, sand bed depth, dry and rainy season, river water,