FUNCTIONING OF LOW LIFT PUMPING STATIONS ON POLDERS - A CASE STUDY OF ZAGOROW, POLAND.

Low lift pumping stations operate primarily within the system of embankments of rivers and reservoirs. Depending on the functions they serve, they can be divided into water table stabilisation pumping stations, drainage pumping stations, flood control pumping stations, and storm pumping stations. One function of this type of pumping station is transfer of water to the nearest water body (a river, lake, or sea). The pumps used in them are characterised by high capacity and, at the same time, low lift. Based on the available data concerning the functioning of the Zagórów pumping station, the characteristics of similar facilities, especially those relating to low lift pumping stations, are presented in this paper. Due to their characteristics, such facilities are both difficult and expensive to operate. The lack of sufficient information about the condition of a pumping station, resulting from the absence of well-maintained monitoring, is a serious issue in this respect. It causes major difficulties when making rational decisions on further operations of such facilities. The present analyses are based on information including the working time, the number of used pumps, and water levels on inlet and outlet sides. The data used in the study are from the period 1991-2013. The conclusion of the analyses is that drainage pumping stations are usually oversized. This may be due to the fact that the geometric difference between the outlet and inlet water level undergoes frequent changes, which requires pumps to manage the high pumping lift. Therefore, it is frequently impossible for the pumps to work efficiently in this kind of facility. The example of Zagórów shows that it is necessary to upgrade the pump units, which were installed more than two decades ago, to address current needs. It should also be pointed out that the basic pump system parameters ought to be adequately monitored. These include electricity consumption, capacity consumption, and water levels on the upper and lower sides. It was found that the optimization of pumping station operation only taking into consideration these parameters makes it possible to reduce operating costs considerably despite the uncertainty associated with hydrometeorological conditions. [ABSTRACT FROM AUTHOR]