Use of habitat suitability modeling in the integrated urban water system modeling of the Drava River (Varazdin, Croatia)

The development of practical tools for providing accurate ecological assessment of rivers and species conditions is necessary to preserve habitats and species, stop degradation and restore water quality. An understanding of the causal mechanisms and processes that affect the ecological water quality and shape macroinvertebrate communities at a local scale has important implications for conservation management and river restoration. This study used the integration of wastewater treatment, river water quality and ecological assessment models to study the effect of upgrading a wastewater treatment plant (WWTP) and their ecological effects for the receiving river. The WWTP and the water quality and quantity of the Drava river in Croatia were modelled in the software WEST. For the ecological modeling, the approach followed was to build habitat suitability and ecological assessment models based on classification trees. This technique allows predicting the biological water quality in terms of the occurrence of macroinvertebrates and the river status according to ecological water quality indices. The ecological models developed were satisfactory, and showed a good predictive performance and good discrimination capacity. Using the integrated ecological model for the Drava river, three scenarios were run and evaluated. The scenario assessment showed that it is necessary an integrated approach for the water management of the Drava river, which considers an upgrading of the WWTP with Nitrogen and Phosphorous removal and the treatment of other diffuse pollution and point sources (including the overflow of the WWTP). Additionally, if an increase in the minimum instream flow after the dams is considered, a higher dilution capacity and a higher self-cleaning capability could be obtained. The results proved that integrated models like the one presented here have an added value for decision support in water management. This kind of integrated approach is useful to get insight in aquatic ecosystems, for assessing investments in sanitation infrastructure of urban wastewater systems considering both, the fulfilling of legal physical chemical emission limits and the ecological state of the receiving waters

Transitioning urban water systems

Water managers acknowledge on a global scale that current practices are no longer sustainable and have an adverse impact on ecology (disruptions to the water cycle and habitats), public health (water qualities, sanitation services) and the economy (flooding, drought and overuse of resources). The idea of applying transitioning approaches stems from growing recognition that changes in water management are urgently needed. The SWITCH transitioning approach was developed by consolidating the project’s existing stakeholder engagement approach with ideas on transition knowledge, an emerging new field of science

IWMI Strategic plan 2004-2008

Strategy planning / Research institutes / Assessment / Research priorities / Research projects / River basins / Water management / Irrigated farming / Land management / Environmental effects / Financial planning

Frameworks for urban water sustainability

Integrated water management, sustainable water management, water sensitive cities, and other formulations are often presented as the latest in a series of paradigms of water management. This implies a unified approach, while urban water debates reflect a wide diversity of political, social, and technical viewpoints. Five distinct but overlapping frameworks for urban water sustainability are evident in research, policy and practice, reflecting wider environmental theory, politics, and discourse. Sustainable development is based on meeting the needs for water and sanitation of the urban poor. Ecological modernization focuses on policies to improve water efficiency and treatment through technological innovation and individual behavior change. Socio‐technical framings aim to understand how change in water systems occurs across physical and institutional scales and addresses the co‐evolution of infrastructures, cultures, and everyday practices. Urban political ecology analyses water infrastructure in terms of relationships of power, pointing to the unequal distribution of costs and benefits of urban water management for the environment and citizens. Radical ecology addresses the relationship between human culture and non‐human nature, proposing fundamental reorganization of society to solve ecological and hydrological crises. Characterizing alternate frameworks of urban water sustainability provides clarity on the underlying assumptions, methods, and politics across a diversity of approaches. Frameworks may be deployed strategically to deliver policy impact, or may reflect deeply held political or epistemological standpoints. Understanding different conceptions of urban water sustainability provides the basis for more constructive dialogue and debate about water and its role in sustainable cites. This article is categorized under: Engineering Water > Planning Water Human Water > Water Governance Water and Life > Conservation, Management, and Awarenes

Business model assessment in faecal sludge management in selected Vietnamese cities

An assessment of business models in faecal sludge management (FSM) in 3 largest Vietnamese cities of Hanoi, Hai Phong, and Ho Chi Minh has been conducted through interview of 1,000 households and survey at 20 FS emptying operators. The public enterprises keep a significant market share for FSM. However, these enterprises run FSM business as a ‘‘must do” activity, which is subsidized by the city’s budget. In order to reduce operation costs and to make benefit, most of private enterprises are practicing illegal FS dumping. Financial status of private enterprises looks less optimistic in scenarios where FS is required to be brought to landfill or composting plant. A number of enterprises would not find capital recovery within 5 years, and some others would face loss. For sustainable FSM business, costs for adequate FSM should be recovered, while regulatory support and coordination role of local authorities are needed