Natural water systems and treatment technologies to cope with water shortages in urbanized areas in India (NaWaTech)

Purpose

Integrated approaches that comprise the entire urban water cycle, reuse wastewater and prevent freshwater pollution, prioritise flexible and cost-effective small-scale natural and technical systems.

Activities

Providing adequate water supply and sanitation, particularly in urban areas, is a challenging task for governments throughout the world. This task is made even more difficult due to predicted dramatic global changes. Population growth, urbanisation, increasing industrialisation, climate change and a steep increase in water consumption are putting pressure on urban water resources.

In order to cope with water shortages in urban areas, there is a need for a paradigm shift from conventional end-of-pipe water management to an integrated approach. This integrated approach should include several actions such as: (i) interventions over the entire urban water cycle (considering wastewater and freshwater both as integrated parts of water resources in general); (ii) optimisation of water use by reusing wastewater and preventing pollution of freshwater source; (iii) prioritisation of small-scale natural and technical systems, which are flexible, cost-effective and require low operation and maintenance.

Natural water systems, such as manmade wetlands and sub-soil filtration and storage via soil aquifer treatment and bank filtration, are such systems. In addition, compact technical systems such as SBRs and MBRs have made a great development step in the last years. Moreover, they can absorb highly and widely varying pollution loads; buffer seasonal fluctuations in the availability of water; and they can be integrated into the urban planning as green infrastructures providing additional socio-economic benefits such as amenity.

In Europe, those systems have been developed for many years and their potential for the application in developing and newly-industrialised countries is widely accepted. However, the location of India and many developing and newly industrialised countries in warmer climate zones sets different environmental conditions.

Taking these facts into account the project NaWaTech aims at maximising the exploitation of natural and compact technical systems and processes for the effective management of municipal water resources, of water supply and sanitation services, and of the municipal water cycle as a whole in urbanised areas of India. On the basis of a detailed inventory of natural and technical treatment systems, the European and Indian consortia have identified several promising axes:

- Wastewater and storm water treatment and reuse for the managed aquifer recharge (MAR) (constructed wetland; SBRs & MBRs, soil aquifer treatment and aquifer storage and recovery);
- Stimulation of water retention and self-purification capacity of water resource via in-stream remediation using eco-hydrology principles
- Improvement of surface water quality via bank filtration (lake or river bank filtration) for the generation of (indirect) potable water
- Secondary treatments for drinking water (sand filtration; membrane filtration; UV disinfection)

Countries of activity

Location of main activity

Filter tags

Cities Constructed wetlands East Asia & Pacific Food security and productive sanitation Greywater or wastewater Other funding source or unspecified Practitioners Resource recovery Specific to one or several countries Technology comparisons Treatment of wastewater or greywater University, education or research institution Urban (entire city) Water (irrigation, process, other)

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