Sediment Augmentation for River Rehabilitation and Management—A Review

Sediment management is an important part of river rehabilitation and management. Global case studies provide a growing number of examples of successful sediment augmentation measures that can counter the adverse effects of disturbed sediment regimes. The initial river state and the objectives of the reported measures can vary largely, however. In this review, a summary of selected case studies is presented, and an objective-focused classification of sediment augmentation measures is introduced. Case-specific restrictions, design approaches and assessment methods based on the literature review and our own experience from working in the field are presented. This summary aims to provide an overview on up-to-date knowledge for applied river rehabilitation and management.

Governing river rehabilitation projects for transformative capacity development

River rehabilitation projects are framed as water security interventions in South Africa. They aim to address water quality and water quantity issues, as well as to improve socio-ecological relationships. These projects acknowledge the value of capacity building and social learning in enhancing water security. However, they adopt different governance approaches and hence have different knowledge construction and capacity building outcomes. This paper employs a ‘governmentality’ framework to analyse the capacity development processes within three river rehabilitation projects in Durban, South Africa. The analysis revealed that the three projects with their different governmentalities produced different capacity development modalities which are utilised to sustain ‘the object of intervention’ in each river rehabilitation project. However, despite these differences, information as the currency of action; the context or site of learning; the importance of building state–citizen relationships; and the need for bridges or intermediaries, emerged as common elements which support capacity building and knowledge sharing across all three projects.

The Biological Assessment and Rehabilitation of the World’s Rivers: An Overview

The biological assessment of rivers i.e., their assessment through use of aquatic assemblages, integrates the effects of multiple-stressors on these systems over time and is essential to evaluate ecosystem condition and establish recovery measures. It has been undertaken in many countries since the 1990s, but not globally. And where national or multi-national monitoring networks have gathered large amounts of data, the poor water body classifications have not necessarily resulted in the rehabilitation of rivers. Thus, here we aimed to identify major gaps in the biological assessment and rehabilitation of rivers worldwide by focusing on the best examples in Asia, Europe, Oceania, and North, Central, and South America. Our study showed that it is not possible so far to draw a world map of the ecological quality of rivers. Biological assessment of rivers and streams is only implemented officially nation-wide and regularly in the European Union, Japan, Republic of Korea, South Africa, and the USA. In Australia, Canada, China, New Zealand, and Singapore it has been implemented officially at the state/province level (in some cases using common protocols) or in major catchments or even only once at the national level to define reference conditions (Australia). In other cases, biological monitoring is driven by a specific problem, impact assessments, water licenses, or the need to rehabilitate a river or a river section (as in Brazil, South Korea, China, Canada, Japan, Australia). In some countries monitoring programs have only been explored by research teams mostly at the catchment or local level (e.g., Brazil, Mexico, Chile, China, India, Malaysia, Thailand, Vietnam) or implemented by citizen science groups (e.g., Southern Africa, Gambia, East Africa, Australia, Brazil, Canada). The existing large-extent assessments show a striking loss of biodiversity in the last 2–3 decades in Japanese and New Zealand rivers (e.g., 42% and 70% of fish species threatened or endangered, respectively). A poor condition (below Good condition) exists in 25% of South Korean rivers, half of the European water bodies, and 44% of USA rivers, while in Australia 30% of the reaches sampled were significantly impaired in 2006. Regarding river rehabilitation, the greatest implementation has occurred in North America, Australia, Northern Europe, Japan, Singapore, and the Republic of Korea. Most rehabilitation measures have been related to improving water quality and river connectivity for fish or the improvement of riparian vegetation. The limited extent of most rehabilitation measures (i.e., not considering the entire catchment) often constrains the improvement of biological condition. Yet, many rehabilitation projects also lack pre-and/or post-monitoring of ecological condition, which prevents assessing the success and shortcomings of the recovery measures. Economic constraints are the most cited limitation for implementing monitoring programs and rehabilitation actions, followed by technical limitations, limited knowledge of the fauna and flora and their life-history traits (especially in Africa, South America and Mexico), and poor awareness by decision-makers. On the other hand, citizen involvement is recognized as key to the success and sustainability of rehabilitation projects. Thus, establishing rehabilitation needs, defining clear goals, tracking progress towards achieving them, and involving local populations and stakeholders are key recommendations for rehabilitation projects (Table 1). Large-extent and long-term monitoring programs are also essential to provide a realistic overview of the condition of rivers worldwide. Soon, the use of DNA biological samples and eDNA to investigate aquatic diversity could contribute to reducing costs and thus increase monitoring efforts and a more complete assessment of biodiversity. Finally, we propose developing transcontinental teams to elaborate and improve technical guidelines for implementing biological monitoring programs and river rehabilitation and establishing common financial and technical frameworks for managing international catchments. We also recommend providing such expert teams through the United Nations Environment Program to aid the extension of biomonitoring, bioassessment, and river rehabilitation knowledge globally.

Guiding Sustainable Development along Rivers in India

<p>Rivers have been a crucial part of human existence and the cradle of ancient civilizations. Historically, all cities developed along river banks. Rivers have played a seminal role in structuring cities the world over. India is recognized as a river nation and has had a long history of mystical affiliation with its rivers. Here rivers are considered sacred and venerated. All human activities and rituals are innately associated with the riverfront. Riverfronts have functioned as crucial socio-cultural religious spaces. In today’s times however Rivers present a gory picture of neglect. Fresh water is polluted by domestic, industrial, agricultural and religious waste. Fortunately, people  over the world have begun to realize the importance of rivers and concentrated efforts to ecologically rehabilitate and restore them are underway. In India, such efforts are mostly hinged on channelizing the riverbank and providing a space for recreation for city dwellers. Activists and water proponents, however, contest this approach and term it to be a mere initiative focussed towards river beautification rather than river rehabilitation. Such initiatives are not necessarily ecologically responsive and sustainable. India has been one of the leading participants of the United Nations and is dedicated to the UN's 2015 sustainable development goals (SDGs). Under SDG 6 and SDG 11, India strives to boost its water bodies, water quality and provide a comprehensive sustainable solution. India initiated the Smart City Projects (SCP's) in 2015, focussing on cities ' overall sustainable development'. Under this project, a total of 100 cities have been identified and more than 60 cities have a plan for riverfront development. These initiatives are targeted at reducing water pollution, providing aid to the riverbank and improving the connect between the city and its river. This paper aims at reviewing the recent Riverfront development proposals in India under the smart city mission and develop a set of indicators as a framework that allows future communities to reclaim their river and river edges in a sustainable manner. Research is conducted in two stages. Phase one is to establish a framework based on the principles of urban design and urban planning policies in India and assess the planned riverfront project. Phase two suggests a multi-criterion sustainability framework in the context of Indian rivers and validate its application using the community discussion process. Discussions involve Indian government officials’ scholars from a variety of disciplines, engineers, designers, and the general public. This framework aims to direct developers, architects, PWDs, environmental authorities, towards sustainable restoration/rehabilitation strategies in the context of Indian rivers. </p><p>Keywords: Riverfront development, River Rehabilitation, River Restoration, Sustainability, Channelization, Smart City Projects</p>