406
T. Ciupa and R. Suligowski
August 2010. In the first city, it was deprived of the supply of drinking water from
the reservoir, and in the second there was flooding.
17.3 Small Streams—Status, Functioning, Management
The majority of small permanent and periodic streams commonly found in urbanized
areas are not covered by continuous quantitative and qualitative monitoring. They are
a very sensitive system reflecting natural and anthropogenic changes in a catchment.
The latter influence, e.g. current conditions of the channel and the bed as well as
disturbances of water circulation, which in turn affects the surface runoff, its relation
to underground runoff and flood wave features, as well as the quality of outflowing
waters [26, 35, 38]. Small urban streams are often the only receiver of surface runoff
waters, and sometimes even municipal and industrial sewage of a legal nature (on the
basis of water-law permits) and illegal (“wild”). These streams, in terms of nature
and ecology, constitute an important living space of animals and plants. In a situation
of strong anthropogenic pressure, they quickly lose their ecological balance, because
nature itself is not able to counteract increasing burdens. Therefore, in some cities
assessments of the condition of selected riverbeds and valley bottoms are carried
out. Resistance to anthropogenic pressure is taken into account in relation to technical and investment activities, e.g. regulation and change of the course of a river
channel, hydraulic engineering [63]. This problem is so important that it has found
its place in the water policy program in the European Union countries [118] and
has been implemented into Polish law [119]. These documents impose requirements
aimed at improving the quality of water discharged through these watercourses. This
state can be recognized by field mapping specifying the current hydromorphological
situation of the valley bottom. Particular attention is paid to the identification of the
structure and stability of biotopes: channel, bank and terrestrial and their ecological
capacity. Values of the riverbed morphometry, hydrodynamic conditions, the method
of bank strengthening and hydrotechnical development are also taken into consideration when valorising the channel and bank biotope. Within selected homogeneous
sections of the river, a visual assessment of the purity of water, sediments, living
space of organisms is made, taking into account the outbreaks of pollution. In turn,
in the valorization of a terrestrial biotope, features of a valley landscape are taken
into account, including land use, diversity of living spaces and the nature of the
relationship between a valley and a watercourse. For the separation and evaluation
of homogeneous sections, several methods are used (e.g. RHS—English, LAWA—
German, HEM—Czech) with varying degrees of details depending on the needs and
scale of the study [e.g. 120, 121]. In urban conditions with strongly differentiated
anthropopressure, it is often necessary to modify and adapt them to local conditions
[54, 63]. So far, in Poland, this type of mapping has been used mainly for the needs
of medium-sized rivers [122], and sporadically small rivers—e.g. in Kielce [63, 78],
D˛ abrowa Górnicza [123]. Common features that determine their low level of conservation and ecological efficiency include, among others: regulation and technical
T. Ciupa and R. Suligowski
August 2010. In the first city, it was deprived of the supply of drinking water from
the reservoir, and in the second there was flooding.
17.3 Small Streams—Status, Functioning, Management
The majority of small permanent and periodic streams commonly found in urbanized
areas are not covered by continuous quantitative and qualitative monitoring. They are
a very sensitive system reflecting natural and anthropogenic changes in a catchment.
The latter influence, e.g. current conditions of the channel and the bed as well as
disturbances of water circulation, which in turn affects the surface runoff, its relation
to underground runoff and flood wave features, as well as the quality of outflowing
waters [26, 35, 38]. Small urban streams are often the only receiver of surface runoff
waters, and sometimes even municipal and industrial sewage of a legal nature (on the
basis of water-law permits) and illegal (“wild”). These streams, in terms of nature
and ecology, constitute an important living space of animals and plants. In a situation
of strong anthropogenic pressure, they quickly lose their ecological balance, because
nature itself is not able to counteract increasing burdens. Therefore, in some cities
assessments of the condition of selected riverbeds and valley bottoms are carried
out. Resistance to anthropogenic pressure is taken into account in relation to technical and investment activities, e.g. regulation and change of the course of a river
channel, hydraulic engineering [63]. This problem is so important that it has found
its place in the water policy program in the European Union countries [118] and
has been implemented into Polish law [119]. These documents impose requirements
aimed at improving the quality of water discharged through these watercourses. This
state can be recognized by field mapping specifying the current hydromorphological
situation of the valley bottom. Particular attention is paid to the identification of the
structure and stability of biotopes: channel, bank and terrestrial and their ecological
capacity. Values of the riverbed morphometry, hydrodynamic conditions, the method
of bank strengthening and hydrotechnical development are also taken into consideration when valorising the channel and bank biotope. Within selected homogeneous
sections of the river, a visual assessment of the purity of water, sediments, living
space of organisms is made, taking into account the outbreaks of pollution. In turn,
in the valorization of a terrestrial biotope, features of a valley landscape are taken
into account, including land use, diversity of living spaces and the nature of the
relationship between a valley and a watercourse. For the separation and evaluation
of homogeneous sections, several methods are used (e.g. RHS—English, LAWA—
German, HEM—Czech) with varying degrees of details depending on the needs and
scale of the study [e.g. 120, 121]. In urban conditions with strongly differentiated
anthropopressure, it is often necessary to modify and adapt them to local conditions
[54, 63]. So far, in Poland, this type of mapping has been used mainly for the needs
of medium-sized rivers [122], and sporadically small rivers—e.g. in Kielce [63, 78],
D˛ abrowa Górnicza [123]. Common features that determine their low level of conservation and ecological efficiency include, among others: regulation and technical