39
Furthermore, the use of water for environmental needs and environmental services
is gaining rising importance (Petts 2009 ). While formerly the environmental needs of
natural ecosystems have not been acknowledged as a factor to be taken into account,
today e.g. the protection of wetlands and the ecological restoration of river ecosystems are increasingly gaining attention, particularly in well-developed countries. In
order to establish this perspective as an eco-hydrological concept, the term “environmental fl ows” (or E-fl ows) has been introduced. An environmental fl ow is defi ned as
the water regime provided within a river, wetland or coastal zone to maintain ecosystems and their benefi ts where there are competing water uses and where fl ows are
regulated. It has been argued that water resources need to be managed to provide
environmental fl ows, either by means of modifi cations of infrastructure or changes in
water allocation policies and entitlements (Dyson et al 2003 ).
3.3 Principles, Trends and Framework Conditions of Major
Water Engineering Projects
Water technologies have been examined from various perspectives and from different disciplinary angles already. This sub-chapter tries to summarise and condense
the fi ndings and experiences made within the scope of major water engineering
projects in different parts of the world. Based upon these general observations, we
try to formulate general “principles” of such projects. Overarching trends in
technology- related water management are defi ned in order to illustrate the relevance
of the topic and the need for interdisciplinary research and assessment approaches.
It is important to note that the focus in this regard is on the aspects that tend to be
underestimated in many current evaluations and impact assessments of MWEPs.
Their undisputedly numerous positive and benefi cial effects for economic and social
development are usually not as underrepresented as are the uncertainties and risks
associated with their implementation.
The statements presented here can be perceived as the conceptual backbone of
the practical parts of this volume and as presuppositions and general observations of
the previous work of the authors. Furthermore, these principles and trends serve as
the basis for an evaluation framework, considering the main compartments of the
relevant social, economic and ecological sub-systems that are affected by technological measures of water management. Aspects of this framework will be covered
throughout the following chapters of this volume.
• Long-term path dependencies caused by MWEPs may affect the future options
for sustainable development of regions and nations.
The provision of water for human needs requires (large-scale) infrastructures,
particularly in countries exhibiting a dry and arid climate. In many cases, the type of
infrastructure chosen for a specifi c region determines the availability of further technological options and the remaining radius of action – now and in the future. This
3 Major Water Engineering Projects: Defi nitions, Framework Conditions, Systemic…
Furthermore, the use of water for environmental needs and environmental services
is gaining rising importance (Petts 2009 ). While formerly the environmental needs of
natural ecosystems have not been acknowledged as a factor to be taken into account,
today e.g. the protection of wetlands and the ecological restoration of river ecosystems are increasingly gaining attention, particularly in well-developed countries. In
order to establish this perspective as an eco-hydrological concept, the term “environmental fl ows” (or E-fl ows) has been introduced. An environmental fl ow is defi ned as
the water regime provided within a river, wetland or coastal zone to maintain ecosystems and their benefi ts where there are competing water uses and where fl ows are
regulated. It has been argued that water resources need to be managed to provide
environmental fl ows, either by means of modifi cations of infrastructure or changes in
water allocation policies and entitlements (Dyson et al 2003 ).
3.3 Principles, Trends and Framework Conditions of Major
Water Engineering Projects
Water technologies have been examined from various perspectives and from different disciplinary angles already. This sub-chapter tries to summarise and condense
the fi ndings and experiences made within the scope of major water engineering
projects in different parts of the world. Based upon these general observations, we
try to formulate general “principles” of such projects. Overarching trends in
technology- related water management are defi ned in order to illustrate the relevance
of the topic and the need for interdisciplinary research and assessment approaches.
It is important to note that the focus in this regard is on the aspects that tend to be
underestimated in many current evaluations and impact assessments of MWEPs.
Their undisputedly numerous positive and benefi cial effects for economic and social
development are usually not as underrepresented as are the uncertainties and risks
associated with their implementation.
The statements presented here can be perceived as the conceptual backbone of
the practical parts of this volume and as presuppositions and general observations of
the previous work of the authors. Furthermore, these principles and trends serve as
the basis for an evaluation framework, considering the main compartments of the
relevant social, economic and ecological sub-systems that are affected by technological measures of water management. Aspects of this framework will be covered
throughout the following chapters of this volume.
• Long-term path dependencies caused by MWEPs may affect the future options
for sustainable development of regions and nations.
The provision of water for human needs requires (large-scale) infrastructures,
particularly in countries exhibiting a dry and arid climate. In many cases, the type of
infrastructure chosen for a specifi c region determines the availability of further technological options and the remaining radius of action – now and in the future. This
3 Major Water Engineering Projects: Defi nitions, Framework Conditions, Systemic…