ANALYZE THE STRESS OF OUR RIVERS AND 0F OUR TERRITORY
Channel artificialization, water pollution, abstraction and reservoir managing have led to the loss of important ecosystems, as riparian ecotones, regularly flooded biotopes, natural stream reaches, riparian corridors and of environmental and biological diversity. The loss regards also functions related to freshwater ecosystems and essential to the biosphere, as sediment transport, hyporreheic dynamics, self-cleaning capacity of rivers, retention and removal of nitrates.
All this in the aim of achieving hydraulic security but, surprisingly, in Italy we now experience a generalised threat from flood events.
It is more and more evident that the growing of impermeable territory, the irresponsible building of civil, industrial and commercial centres in risk areas, have enhanced the frequency and magnitude of flooding and of their effects.
These events are therefore not "natural disasters" but consequence of bad management of rivers and of improper land-use.
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TO AVOID SHORT-SIGHTED POLITICS AND BEHAVIOURS
The reasons of bad management are thus mainly due to an approach restricted both in terms of variety of functions and evolution in time: rivers have been considered only as potential danger (and so to be tamed), or energy to be used and, frequently, a mere wastewater channel.
The main aim of water protection policies (based on effluent control) was to guarantee a given quality and quantity of water for human proposes, with little or no consideration of the ecological and environmental stability of the river itself.
In order to gain hydraulic security, rivers have been changed to geometric channels, rather than seeking good practices in land-use managing, leaving stream corridors wide enough for peak floods and avoiding human activities in potential flooding areas.
Thus rivers have been impounded, deprived of their vegetation, restricted to suspended channels, embanked, interrupted by weirs, sluices, culverts, dams etc.
The same was for the network of ditches, transformed to reclaim land for agriculture or settlement.
The maintenance of such waterways is based on the removal of any kind of vegetation and on dragging and reshaping of the channel. This has led to a generalised decay of the ecosystems and to higher water velocity with consequent more erosion of banks and other structures.
A public uncoordinated management thus oriented (or disoriented?) has too frequently allowed pirating of stream resources, mainly gravel and sand abstraction.
The low sensibility of the population to environmental values has been the fertile substrate for these politics and behaviours.
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PROMOTE STREAM RESTORATION
It is thus urgent to change direction and move towards river restoration. With this we mean modifying of the ecological and environmental setting (ecological functions, degree of naturalness, landscape, biodiversity etc.), of the physical and hydraulic parameters (channel changes, regulation and exploitation, solid transport, hazard) and of normative, administrative and institutional aspects (land-use, economic and financial possibilities, co-ordination between institutions). Modifications are intended to fulfil, in a sustainable manner, the different environmental, economic and social goal. Thus our aim is to achieve naturalness, landscape and ecological quality and function together with the lowest hydraulic risk and a rational exploitation of water resources (drinking water, irrigation, hydropower etc).
River restoration is based on structures, practices and management, by means of an integrated approach in which active participation of the social and institutional parts plays a key role.
It is also necessary to admit that the aims proposed by the parts are most frequently in conflict, as is for the groups of interest involved. For this reason, concerted solutions must be sought in order to maximise environmental and social benefits and leaving, as far as possible, none "worse than before".
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PROMOTE THE CIRF APPROACH
The essential lines of an innovative approach are:
systemic vision, that considers interrelations between components and processes, and holistic approach, in order to evaluate the effects from all relevant points of view as a whole;
participation and concertation of all the involved parties, whose interests are often in conflict;
new goals for public action and possibilities to foster private initiatives (maintaining the control to the public administration in order to assure sustainable and balanced development);
to reclaim parts of the territory to the river, so as to provide, among other effects, flood control, natural geomorphologic evolution, ecosystem health and natural landscape, ecological corridors, phytodepuration (buffer ecosystems);
to choose low impact criteria and techniques (natural engineering) for hydraulic defence (in particular against erosion and establishing flooding areas) and to promote actions to restore and exploit natural environments;
new solutions to old problems, as for example:
sustainable management of restored areas using biomass for energy and/or phytodepuration and riparian vegetation for water quality control
planning projects for discharge control, flood defence or restoration, involving also gravel and sand abstraction and exploitation
promoting agricultural changes by means of Community or local funding and possible connections with tourism and protected areas
integrated evaluation of actions based on multicriteria analysis (conflicting interests and social parts)
multidisciplinariety and interaction among technicians with different background to avoid the mere engineering approach
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