Greenhouse gas (GHG) emissions are primarily due to the exploitation of fossil fuel as an energy source, and one of the energy alternatives for the reduction of emissions is the use of renewable energy sources; one of these is solar irradiation conversion to useable clean energy. In the city of Istanbul, floating photovoltaic (FPV) installation started in 2017, on one of the lakes with an extensive surface area, Buyukcekmece, which supplies water to the city. To reduce evaporation losses and to generate electricity, two FPV prototypes were installed, with capacities of 9 and 90 kWp. Due to the location and climate of Buyukcekmece Lake, all system components including steel construction, metal sheet, maintenance way, connecting parts, and pontoons must resist extreme weather conditions, especially harsh waves and high wind loads. This paper is focused on a survey of the survival performance of the FPV system under real weather conditions without blockage of evaporation, just the reduction of it. Stress and strain tests were also applied to pontoons, one of the vital components for floating systems. The elasticity module, yield limit and tensile strength were evaluated as 0.42 GPA, 11.5 mPA, and 19 mPA, respectively. The wave height was calculated by means of four practical relationships, taking the lake's distinctive characteristics into consideration. The electricity generation of 90 kWp FPV measured for June 2017 was 5189 kWh. The structural and electrical performance results from these systems in the city of Istanbul could be applied further to large scale FPV applications in water reservoirs nationally and internationally.