The phenomenon of large volumes of currents resulting from excessive precipitation or snowmelt not fit in the river bed is called a flooding. Turkey, because of its geographical location, especially because of the impact of the Black Sea, Marmara, Aegean and Mediterranean sea is frequently observed rainfall, and the consequent loss of life and property is a country where occurs. In the flooding incidents experienced, it is seen that the major reason in the areas close to the settlements is mostly inappropriate and inadequate interventions to the river beds and wrong reconstruction practices. Zoning applications on the sandy areas where the rivers meet the sea and on the alluvial flats without considering the flood boundary cause many engineering problems. In this study, the effect of pouring into the sea was investigated in the Işıklar river, which is located in the coastal line of the Kumbağ district of Tekirdağ province and reaches the sea passing through the residential areas, and the water surface profile of the sunken hydraulic section was modeled with the help of the HEC-RAS (Hydrologic Engineering Center-River Analisis System) analysis program and the results were compared with the profile of the water face in the non-submerged hydraulic section. With the effect of submerged hydraulic section and water pouring into the sea, it was observed that the water surface profile decreased significantly in the sections close to the sea and it was also observed that this downward trend was effective until the inner parts.