World Water Day celebrates Green Infrastructure

World Water Day poster. Photo credit, UNESCO.

Following the 8th World Water Forum in Brazil, World Water Day 2018 has been dedicated to Nature for Water, a concept that explores nature-based solutions for water challenges faced in the 21st century.

The new campaign is called The Answer is in Nature, and raises awareness of nature-based solutions. The central message is that solutions, such as planting trees to replenish forests, reconnecting rivers to floodplains, and restoring wetlands, is a sustainable and cost-effective way to help rebalance the water cycle, mitigate the effects of climate change and improve human health and livelihoods.

“For too long, the world has turned first to human-built, or ‘grey’ infrastructure to improve water management,” states Gilbert Houngbo, Chair of UN-Water and President of the International Fund for Agricultural Development, in the foreword of the new report. “In so doing, it has often brushed aside traditional and Indigenous knowledge that embraces greener approaches. Three years into the 2030 Agenda for Sustainable Development, it is time for us to re-examine nature-based solutions to help achieve water management objectives,” added Houngbo.

More World Water Day information

Focusing on ‘environmental engineering’

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So-called green infrastructure, as opposed to traditional grey infrastructure, focuses on preserving the functions of ecosystems, both natural and built, and environmental engineering rather than civil engineering to improve the management of water resources. This has multiple applications in agriculture, the greatest consumer of water by far. Green infrastructure can help reduce pressures on land use, while limiting pollution, soil erosion and water requirements by contributing to the development of more effective and economic irrigation systems, for example.

In 1986, the State of Rajasthan, in India, experienced one of the worst droughts in its history. Over the following years, an NGO worked alongside local communities to set up water harvesting structures and regenerate soils and forests in the region. This led to a 30% increase in forest cover, while groundwater levels rose several metres and cropland productivity improved.

Originally introduced in Madagascar, its System of Rice Intensification helps to restore the hydrological and ecological functioning of soils rather than using new crop varieties or chemical products. It enables savings of 25% – 50% in water requirements and 80% – 90% in seeds, while raising paddy output by 25% – 50%, depending on the region in which it is implemented. It is estimated that agricultural production could be increased by about 20% worldwide if greener water management practices were used.

One study cited by the new World Water Forum report reviewed agricultural development projects in 57 low-income countries and found that using water more efficiently, combined with reductions in the use of pesticides and improvements in soil cover, increased average crop yields by 79%.

“We need new solutions in managing water resources so as to meet emerging challenges to water security caused by population growth and climate change,” said Audrey Azoulay, Director-General of UNESCO, in a statement to media. “If we do nothing, some five billion people will be living in areas with poor access to water by 2050. This report proposes solutions that are based on nature to manage water better. This is a major task all of us need to accomplish together responsibly so as to avoid water-related conflicts,” added Azoulay.

Green solutions have also shown great potential in urban areas. While vegetated walls and roof gardens are perhaps the most recognizable examples, others include measures to recycle and harvest water, water retention hollows to recharge groundwater and the protection of watersheds that supply urban areas. New York City has been protecting its three largest watersheds since the late 1990s. Disposing of the largest unfiltered water supply in the U.S., the City now saves more than $300 million each year on water treatment and maintenance costs.

Faced with an ever-increasing demand for water, countries and municipalities are showing a growing interest in green solutions. China, for example, recently initiated a project entitled “Sponge City” to improve water availability in urban settlements. By 2020, it will build 16 pilot Sponge Cities across the country. Their goal is to recycle 70% of rainwater through greater soil permeation, retention and storage, water purification and the restoration of adjacent wetlands.

Wetlands only cover about 2.6% of the planet but play a disproportionately large role in hydrology, the report states. They directly impact water quality by filtering toxic substances from pesticides, industrial and mining discharges. There is evidence that wetlands alone can remove 20% – 60% of metals in water and trap 80% – 90% of sediment from runoff. Some countries have even created wetlands to treat industrial wastewater, at least partially. Over recent years, Ukraine, for example, has been experimenting with artificial wetlands to filter some pharmaceutical products from wastewater.


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