SAILING THE WARTA

Warta - princess of Polish rivers

The Wisła is called the queen of Po- lish rivers, the longest and proudest of Polish rivers. I think, deservedly. What title should we give our Wielkopolska River Warta? Not queen, since the title has already been given, though it deserves the title of princess on account of its length; 808 kilometers from the source in Kromolow near Zawierec, to the river's estuary at the Odra in Kostrzyn, thus being the third longest river in Poland - and not only because of this. It is also worth knowing that the Warta has a catchment-area of 54 thousand sq. kilometers greater than that of the Odra, up to the place where the Warta joins. The width of the river varies; in the upper reaches several to many meters, close to the estuary, about 100-120.

It bears no comparison to the Wisła that has a width of over one kilometer. The charm of the Warta though is no lesser, fully deserving its princess title. Its depth is from 40-50 centimeters to a few meters but depth is not at all though the reading from the water measuring staff that we can hear daily in the afternoon on the radio. It is not the depth of the river since the beginning of the measuring staff, the so called 0, is in practice placed considerably below the river floor. That is why we speak of the state of the river, not its depth. Every river has its own hydrological system described by characteristic amounts of its water levels as well as the amount of water flow. When there is little water flowing, the water levels are low and we speak of low water levels and flows. In contrast, when there is a lot of water flowing, we speak of high water levels and flows. We also differentiate average water levels and flows.

How does this look on the Warta? Is it a capricious river? Does it carry a lot or little water? Is the threat of draught greater than flood? The extent of this depends on the place that we give since the size of the catchment-area does not have an influence. If we take a profile in Poznań, for the period 1951-1980: average low flow was 35 m3/s, average flow 101 m3/s and average high flow 356 m3/s. The flood water flow level is about 1000-1300 m3/s. The same profiles for Gorzow Wielkopolska are: 100 m3/s average low flow, 212 m3/s average flow and 510 m3/s average high flow. The flood water flow level is 1300-1500 m3/s. In comparison, the flood water flow of the Wisła in Warsaw amounts to several thousand m3/s. The Warta is not particularly capricious since in its course it has several natural pockets of flood land with a capacity of 500 mln m3.

Janusz Wiśniewski
Deputy Director, Regional Board of Water Resource Management in Poznań