Stromwater in Ukraine – especially in the city of Lviev will be presented by doc. Volodymyr Zhuk.
Zhuk Volodymyr obtained PhD degree in Hydraulics and Engineering Hydrology in 2000. Currently works at position of Assoc. Prof. of the Department of Hydraulics and Sanitary Engineering at Lviv Polytechnic National University. V. Zhuk was scientific adviser of four successfully completed PhD theses, is an author of above 150 scientific publications in the fields of stormwater modeling and management, applied and experimental fluid dynamics, wastewater treatment and sewage sludge utilization.
An important feature of the Lviv city is its location on the line of the Main European watershed between the Baltic Sea and Black Sea basins. The Poltva River which has sources on the territory of the city of Lviv, is currently the main sewer collector of the city. The city’s drainage system consists of about 800 km of sewers, 15 sewerage pumping stations and two sites of the wastewater treatment plant (WWTP). Most of the city’s sewerage networks are of the combined type, so it can cause serious water pollution problems during combined sewer overflow.
The scientific estimations of maximum daily discharges of wastewaters at the inlet of the Lviv WWTP, as well as the maximum flow rates of the stormwater hydrographs in the critical cross-sections, are fulfilled.
Analysis of the change of the depth of the annual precipitations in the Lviv city is performed for the period from 1945 to 2018. Increase of the depth of the annual layer is equal on average 1.56 mm/year. Dependence of the daily maximum rainfall depth from the return period is obtained.
Lviv has been intensively urbanized over the last 50 years, since the city’s largest sewers were built. Baltic Sea drainage catchment of the Lviv city, affecting on the flow rate at the inlet of the Lviv wastewater treatment plant (WWTP), has grown to almost 60 km2. At the same time, the proportion of water impervious areas has increased significantly. A detailed hydrologic analysis was performed using geographic information systems and field investigations for the 1000 ha territory of the Lviv city to find the total and effective imperviousness and to estimate the runoff coefficient values. Correlations between the total and effective imperviousness are described by the power low dependence pef=(ptot)n.
Main challenges of the stormwater drainage system in the Lviv city are analyzed. The principal tasks and methods of the stormwater management on the territory of the Lviv city are discussed.