24
K. Kubiak-Wójcicka
of anthropogenic lakes reaches several thousand, and their surface area exceeds 100
km
2 .
A significant proportion of the man-made reservoirs was created in the 1960s and
1970s. Of the 69 largest reservoirs with a capacity of more than 5 hm
3 , only 6 were
created after 2000. Most man-made reservoirs are used in energy production. The
hydroelectric power plant in Włocławek (162 MW) has the greatest power of the
hydropower plants. The highest installed power is in pumped storage power plants
such as ˙
Zarnowiec (716 MW) and Por˛ abka- ˙
Zar (500 MW), which use both natural
and man-made reservoirs.
The total amount of water accumulated in the 69 man-made reservoirs of capacity
exceeding 5 hm
3 is 3,678 hm
3 , which is about 6% of the average total annual outflow
from the years 1951–2015. According to many authors, reservoir retention in Poland
is too small to limit the effects of a lack or excess of water [18–20]. The largest
man-made reservoir in central Poland—the Włocławek Reservoir—has very limited
capacity to retain flood waters. The turnover of water in the reservoir is very quick,
at every 5 days, and with high flood flows above 4,000 m
3. s
−1 , the turnover period
drops below one day [9].
2.3 The Legal Classification of Inland Surface Waters
Water management in Poland is regulated by the Water Law Act of 20 July 2017
(Journal of Laws of 2017, item 1566, as amended). The Act regulates matters relating
to the ownership of waters and lands covered with waters, as well as the principles for
managing these components as the property of the State Treasury. According to this
law, inland surface waters are divided into flowing inland waters and standing inland
waters. Flowing inland waters are waters in natural watercourses and the springs
from which these watercourses originate; lakes and other natural water reservoirs
with continuous or periodic natural inflow or outflow of surface waters; and manmade water reservoirs located on flowing waters and canals. Standing inland waters
are inland waters in lakes and other natural water reservoirs not directly connected
with flowing inland surface waters. Waters are owned by the State Treasury, and
other natural or legal persons. Inland flowing waters classed as public waters are not
subject to civil trade, except in cases specified in the Act. The issues of ownership
of surface waters in Poland and its legal consequences are addressed in the study by
[21, 22].
2.4 Unit Outflow
As mentioned earlier, the size of water resources depends mainly on climatic conditions, which are variable. The unit outflow from the river basins of the main Polish
rivers is a measure of the diversity of water resources. The average unit outflow from
K. Kubiak-Wójcicka
of anthropogenic lakes reaches several thousand, and their surface area exceeds 100
km
2 .
A significant proportion of the man-made reservoirs was created in the 1960s and
1970s. Of the 69 largest reservoirs with a capacity of more than 5 hm
3 , only 6 were
created after 2000. Most man-made reservoirs are used in energy production. The
hydroelectric power plant in Włocławek (162 MW) has the greatest power of the
hydropower plants. The highest installed power is in pumped storage power plants
such as ˙
Zarnowiec (716 MW) and Por˛ abka- ˙
Zar (500 MW), which use both natural
and man-made reservoirs.
The total amount of water accumulated in the 69 man-made reservoirs of capacity
exceeding 5 hm
3 is 3,678 hm
3 , which is about 6% of the average total annual outflow
from the years 1951–2015. According to many authors, reservoir retention in Poland
is too small to limit the effects of a lack or excess of water [18–20]. The largest
man-made reservoir in central Poland—the Włocławek Reservoir—has very limited
capacity to retain flood waters. The turnover of water in the reservoir is very quick,
at every 5 days, and with high flood flows above 4,000 m
3. s
−1 , the turnover period
drops below one day [9].
2.3 The Legal Classification of Inland Surface Waters
Water management in Poland is regulated by the Water Law Act of 20 July 2017
(Journal of Laws of 2017, item 1566, as amended). The Act regulates matters relating
to the ownership of waters and lands covered with waters, as well as the principles for
managing these components as the property of the State Treasury. According to this
law, inland surface waters are divided into flowing inland waters and standing inland
waters. Flowing inland waters are waters in natural watercourses and the springs
from which these watercourses originate; lakes and other natural water reservoirs
with continuous or periodic natural inflow or outflow of surface waters; and manmade water reservoirs located on flowing waters and canals. Standing inland waters
are inland waters in lakes and other natural water reservoirs not directly connected
with flowing inland surface waters. Waters are owned by the State Treasury, and
other natural or legal persons. Inland flowing waters classed as public waters are not
subject to civil trade, except in cases specified in the Act. The issues of ownership
of surface waters in Poland and its legal consequences are addressed in the study by
[21, 22].
2.4 Unit Outflow
As mentioned earlier, the size of water resources depends mainly on climatic conditions, which are variable. The unit outflow from the river basins of the main Polish
rivers is a measure of the diversity of water resources. The average unit outflow from