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I
nternational
C
ooperation
on
W
ater
S
ciences
and
R
esearch
Rehabilitation plans were elaborated for the river
and Sokołówka River Park, to improve the ecologi-
cal status of the river. This increased the capacity
for water retention, groundwater amelioration and
vegetation growth and improved social access and
use of the area.
Space and expertise were created through higher,
pre- and post-doctoral education, awareness raising and
training, empowered decision-making, fostering inter-
institutional cooperation for better water management
24
and triggering several bottom-up initiatives, including
the implementation of basin management plans in new
investments and the participation of NGOs.
Through these activities, the city authorities moved
towards restoring the quality of the city through an
integrated approach in which environmental reha-
bilitation and spatial planning are as important
as economical and social issues. The Blue-Green
Network concept was included in the Strategy of
Integrated Development of the City of Łód
ź
, 2020+.
Systematic rehabilitation of green and blue areas
enables recognition and a closer association of envi-
ronmental heritage with the revitalization of the
city’s historical industrial architecture.
Translation of solutions for Africa
Ethiopia is one of the biggest countries of the African
continent with an impressive history and high poten-
ment,
20
was tested in Łód
ź
, Poland. The Blue-Green Network concept
21
applies an ecohydrology approach at the city scale, connecting river
valleys and green spaces. Such an approach helps to reduce stormwater-
related risks without investing in costly hard (grey) infrastructure. It
improves the microclimate and encourages healthy lifestyles by provid-
ing space for recreation. The city also becomes resilient to global climate
change while its improved image attracts business, contributing to
economic development.
The Blue-Green Network concept was tested at a demonstration
river, the Sokołówka, which is supplied by stormwater outlets,
almost lacking natural flow. The middle section has maintained a
semi-natural character, holding value for city inhabitants as an area
of recreation. The measures attempted to harmonize the river’s exist-
ing hydrotechnical infrastructure with the potential of its ecosystem,
to enhance its capacity for absorbing increased water and pollutant
fluxes without compromising its quality and appearance.
22
A Sequential Stormwater Biofiltration System (SSSB), contain-
ing sedimentation, biogeochemical and constructed wetland zones,
was constructed in the upper section of the Sokołówka. In the first
two experimental years of its operation, the system has reduced
suspended matter by more than 90 per cent and concentrations of
total nitrogen and phosphorus by up to 60 per cent.
23
A detention
pond recently constructed upstream of the SSSB stabilizes the river
flow and further increases the system’s efficiency.
A cascade of retention reservoirs was constructed on the river to
mitigate extreme flows and hydrological stress. Shaping the reservoir’s
hydrodynamics and phytoremediation gave it the capacity to absorb the
increased nutrient loads without the appearance of toxic algal blooms.
The first stage of the implementation of the Blue-Green Network concept: Sokołówka river in Łód
ź
Source: Wagner and Zalewski, 2009; updated