One of the most important activities that can be evaluated in the management of flood water spreading is recognition of flood water spreading systems operation and artificial recharge of aquifers in relation with other natural factors affecting the recharge of aquifers. The purpose of this paper is evaluating the effect of floodwater spreading projects on flood control and recharge of downstream groundwater aquifer in Fasa Gareh Baygon plain in the unprecedented flood event of Feb. 2017. For the purpose of aforementioned study, variation of floodwater depth in the Bishehzard River during the period of the flood event (13.02.2017 to 18.02.2017) and volume of outflow and inflow were measured. The results showed that the maximum depth of the flood in river was 176 cm with a maximum flow of 330 m3/s. Within the water spreading system, this depth changes into a thin layer of 8 cm on the edge of the spreading channels, which caused not only control of flood velocity but also prevented soil erosion. In order to understand the role of flood water spreading on aquifer recharge, 6 observation wells (piezometers) and 1 well were monitored for 2 months before and 5 months after the floods occur. The results showed that 2 months after the occurrence of flood, water started to affect the aquifer. In this event, about 9924313 cubic meters (between 9281731 and 11423670 cubic meters) of water was penetrated into the aquifer. The drinking water well of the Kowsar station (W1() located at the center of the flood water spreading system,far from the agricultural harvesting area and outside the forest region) shows the highest increase of water level (2.5 m). Sustainable groundwater supply is essential for continuing activity in this area and similar regions. Based on the results of this study and researches carried out in 37 other parts of the country, it is possible to manage the water with a high degree of reliability by implementing flood water spreading systems. Readiness to use rare events happening in these kind of areas is very necessary.