Abstract A system optimization method was used, which consists in the consistent justification of optimal technological and constructive solutions and parameters of drainage polder systems during the development of their projects. This is done in compliance with modern economic and environmental requirements according to criteria and models for di erent levels of management decision-making over time (project, planned operation). Based on the performed relevant predictive and optimization calculations for the conditions of the real object, the following three tasks have been accomplished. (1) The optimal pump module at the stage of operation for the existing polder drainage system has been substantiated. (2) The design of the pumping unit and the parameters of its components during the reconstruction of the polder drainage system have been improved. This made it possible to reduce the load on the pumping equipment, the duration of its operation, and the cost of electricity by 20–40%, depending on the water level of the year. The improvement was carried out by the diversion of the corresponding part of the surface runo with additionally introduced gravity elements in the form of a puncture in the body of the protective dam and a siphon intake. (3) We have substantiated the optimal water regulation technology for the existing polder drainage system in modern and forecast weather and climate conditions, which will ensure the maintenance of the necessary water-air regime of the drained soils in di erent phases of the growing season of agricultural crops. This will make it possible, on demand, to increase the energy and general environmental and economic e ciency during their creation and functioning of the polder drainage system in accordance with modern changing conditions.