The results of geophysical work carried out in 2019 by the Integrated Marine Research Center of Saint-Petersburg State University (IMRC SPbU) on Suzdal Lakes, Saint-Petersburg, are presented. The work was a part of comprehensive environmental survey of the city reservoirs. The methods of ultrahighresolution seismoacoustics, georadiolocation (GPR) and electrical resistivity tomography (ERT) were used. The main goal of geophysical work was to determine the thickness of bottom sediments to evaluate the shape of lake basins. The work has demonstrated that gas saturation of silt enriched with biological material does not allow us to use seismoacoustics for identification the thickness and structure of bottom sediments in the urban area. GPR with a low-frequency antenna has shown rather high efficiency in studying bottom sediments at depths less than about 2 m. However, high water mineralization, typical of urban reservoirs, leading to a strong attenuation of electromagnetic pulses with depth, limits the use of GPR at greater depths. To study bottom sediments to the entire depth and determine the shape of lake basins under conditions of high electrical conductivity of water and/or gas-saturated sediments, ERT method can be recommended, including continuous resistivity profiling (CRP) technique for large water reservoirs.