11.4 Multilevel and Multiscale Issues and Measures
A comparative analysis of three drinking water provision issues, in the Vilaine, in
Eifel-Rur, and in Flanders, can be particularly illuminating, as they present similar
problems in very contrasting contexts, different levels, and scales involved as well
as a diversity of other factors influencing them. In the case of the Vilaine, problems
of water quantity related to the Arzal dam reservoir translate into a problem of water
quality. As explained in further detail previously in this chapter, in dry periods the
low inflow from the Vilaine river and the intrusion of salt water through the lock for
sailing boats are increasingly causing water quality bottlenecks for the drinking
water plant. The position of the reservoir at the river mouth is downstream the big
catchment area affecting the reservoir (of slightly over 10,000 km
2 ), which in turn
implies a large scale and a huge number of administrative levels to be potentially involved in the different possible solutions. This position of the reservoir also
means that it is impacted by the water management decisions of many different
actors and sectors. A series of sectors (including the traditionally strong agricultural
sector) rely on water management, both in terms of water availability and in terms
of water drainage, and for decisions affecting the region’s water management the
different needs have to be aligned between the parties.
Whereas this dependency of drinking water provision on the outcomes of water
management measures (such as those derived from the implementation of the
WFD) would seem a problematic dependency, in practice the Vilaine catchment
water board (IAV) is responsible for both drinking water provision for water
companies and for implementing the Water Framework Directive. This means that
it is in a privileged position to keep track of issues affecting water quality and react
accordingly to possible problems. IAV has recourse to an array of possible solutions to address their water quality issues. For instance, they have the possibility of
implementing measures throughout the catchment in order to avoid excessive water
level drop in summer months by adding small dams along the stream and tributaries. However, these options seem less attractive than improving the lock system
to decrease saline water intrusion, which is the solution that the IAV is currently
evaluating using a prototype (within the DROP project framework). The solution
addresses an existing inefficiency and does so at one point which is under the
management control of the water board. Decentralized options may require the
cooperation of other stakeholders and continuous efforts over time and therefore
seem more complex to implement efficiently.
In the case of the Eifel-Rur region, dry years also create water quality problems
in one reservoir, but these problems are of another kind, as they are related to issues
of eutrophication. Dry years thus mean that the quality and temperature of the water
provided by this particular reservoir can be compromised; creating issues for the
drinking water company supplied by the water board. The issue is very limited in
scale, as the affected reservoir is upstream within the watershed. The reservoir’s
catchment area is mountainous, mainly forested (i.e., not much agriculture), has
hardly any population, and with a size in the order of a few hundred km
2 . This
11 Cross-cutting Perspective Freshwater
223
A comparative analysis of three drinking water provision issues, in the Vilaine, in
Eifel-Rur, and in Flanders, can be particularly illuminating, as they present similar
problems in very contrasting contexts, different levels, and scales involved as well
as a diversity of other factors influencing them. In the case of the Vilaine, problems
of water quantity related to the Arzal dam reservoir translate into a problem of water
quality. As explained in further detail previously in this chapter, in dry periods the
low inflow from the Vilaine river and the intrusion of salt water through the lock for
sailing boats are increasingly causing water quality bottlenecks for the drinking
water plant. The position of the reservoir at the river mouth is downstream the big
catchment area affecting the reservoir (of slightly over 10,000 km
2 ), which in turn
implies a large scale and a huge number of administrative levels to be potentially involved in the different possible solutions. This position of the reservoir also
means that it is impacted by the water management decisions of many different
actors and sectors. A series of sectors (including the traditionally strong agricultural
sector) rely on water management, both in terms of water availability and in terms
of water drainage, and for decisions affecting the region’s water management the
different needs have to be aligned between the parties.
Whereas this dependency of drinking water provision on the outcomes of water
management measures (such as those derived from the implementation of the
WFD) would seem a problematic dependency, in practice the Vilaine catchment
water board (IAV) is responsible for both drinking water provision for water
companies and for implementing the Water Framework Directive. This means that
it is in a privileged position to keep track of issues affecting water quality and react
accordingly to possible problems. IAV has recourse to an array of possible solutions to address their water quality issues. For instance, they have the possibility of
implementing measures throughout the catchment in order to avoid excessive water
level drop in summer months by adding small dams along the stream and tributaries. However, these options seem less attractive than improving the lock system
to decrease saline water intrusion, which is the solution that the IAV is currently
evaluating using a prototype (within the DROP project framework). The solution
addresses an existing inefficiency and does so at one point which is under the
management control of the water board. Decentralized options may require the
cooperation of other stakeholders and continuous efforts over time and therefore
seem more complex to implement efficiently.
In the case of the Eifel-Rur region, dry years also create water quality problems
in one reservoir, but these problems are of another kind, as they are related to issues
of eutrophication. Dry years thus mean that the quality and temperature of the water
provided by this particular reservoir can be compromised; creating issues for the
drinking water company supplied by the water board. The issue is very limited in
scale, as the affected reservoir is upstream within the watershed. The reservoir’s
catchment area is mountainous, mainly forested (i.e., not much agriculture), has
hardly any population, and with a size in the order of a few hundred km
2 . This
11 Cross-cutting Perspective Freshwater
223