22 March: World Water Day 2017 on Wastewater

It is not that water is necessary to life, water is life, said Saint-Exupéry.

Water, a natural resource, is the source of life and an essential commodity for most of the economic activities of mankind. On 22 March of each year, the UN World Water Day is organized to focus attention on the importance of freshwater, to advocate for the sustainable management of freshwater resources, and to deal with the crisis of this important resource.




This year’s theme will be “Wastewater“, which is considered a valuable resource in the circular economy. The management of wastewater is an effective investment in the preservation of ecosystems and human health.





The campaign ‘’why waste water?’’ is meant to encourage the reduction and reuse of wastewater.

Over 80% of the wastewater generated by society flows back into the ecosystem without being treated or reused.

The opportunities from exploiting wastewater as a resource are enormous. Safely managed wastewater is an affordable and sustainable source of water, energy, nutrients and other recoverable materials.

The costs of wastewater management are greatly out- weighed by the benefits to human health, economic development and environmental sustainability.



Today, according to the United Nations, more than 663 million people live without access to clean water and at least 1.8 billion people globally use a source of drinking water that is fecally contaminated.

In the Mediterranean, 86% of the water resources are located on its northern shore. Meanwhile, 60% (180 million) of the world population lacking water lives in one of the countries around the Mediterranean Sea. Of these 180 million inhabitants, 60 million are living with extremely limited water resources, and 20 million do not have access to drinking water (MWO 2012_Technical report: Mediterranean Wetlands Outlook 2012).


Tunisia, photo M. Renaudin (Wetlands International)

Tunisia, photo M. Renaudin (Wetlands International)


Scientists expect water scarcity to become widespread due to a number of reasons: a) the irresponsible use of water; b) the strong increase in water demand due to the growing world population; and c) extreme weather events such as droughts that aggravate aridity and reduce resources in many regions.

The demand for fresh water is rising sharply as the resources of the planet become ever more scarce. Today, if we do not act quickly to find solutions for the preservation of water resources on our planet, this lack of water can lead to famines, epidemics, political instability and even military conflicts. Countries are invited today to adopt strategies that include nature-based solutions that are an essential element in the fight against water scarcity.

Healthy, resilient and functional ecosystems such as wetlands can be an economically viable and sustainable solution, often less costly in the long term than technological investments.

Wetlands help to treat wastewater

Wetlands cover approximately 12.8 billion hectares – roughly 6% of the Earth’s land surface – of which 570 million hectares are freshwater wetlands (PNUE/WCMC). In the Mediterranean, about 80% of this renewable water used comes from surface sources (rivers, lakes, and dams), and the rest from aquifers (MWO 2012_Technical report: Mediterranean Wetlands Outlook 2012).

The wetlands are natural infrastructures that ensure the regulation of the water cycle and the maintenance and improvement of water quality. During wet periods, wetlands act as natural sponges capturing water, filtering it and then storing it on the surface and in the aquifers. Some wetlands can store up to 15,000 m3 of water per ha (Ramsar Convention Bureau, 2001). During droughts, they release gradually the stored water for population and nature use.

Wetlands, in particular marshes and riparian vegetation, are veritable natural purification stations. Sometimes compared to our kidneys, they are capable of transforming and of absorbing many pollutants. They contribute considerably to the natural filtration of water and to the improvement of its quality when polluted, thus providing a service that is especially important for human societies. Water charged with sediments, nutrients, pollutants and pathogens that flows through a wetland is often considerably cleaner at its exit downstream (Millennium Ecosystem Assessment, 2005; Harrison et al 2010). Some wetlands have been found to reduce the concentration of nitrates by more than 80% (Millennium Ecosystem Assessment, 2005). A project in Spain was carried out by rehabilitating wetlands and restoring their natural functioning to treat polluted water. (See project sheet here).

The use of wetlands in the treatment of urban wastewater has been developing rapidly since the mid-1980s. The lagooning technique is a biological wastewater approach in which treatment is provided by aquatic vegetation and microorganisms, mainly algae and bacteria. This device is being employed both inland and on the coastal strip (learn more about the functioning and the natural resources of the Rochefort lagooning station, France).



The Rochefort lagooning station, France. Photo: © LPO


Although they are an important source of fresh water, many wetlands are now degraded. They are also the transport vehicle for waste, in particular plastics: Over 80% of the annual input comes from land-based sources via wetlands (Rapport 2016 of Eunomia).

The role of MedWet in preserving water resources

The UN’s Sustainable Development Goals (SDGs), otherwise known as the Global Goals, are a universal call to action to end poverty, protect the planet, and ensure that all people enjoy peace and prosperity.

The main objective of the MedWet Framework for Action 2016-2030 is to contribute to achieving, in the Mediterranean region, some of the targets of the SDGs which present a special interest to MedWet countries, in particular SDG 6 – Ensure availability and sustainable management of water and sanitation for all – through actions in the field of wetland conservation and sustainable use.

Well-managed, these ecosystems are providers of clean water and they can serve as a primary treatment of some used waters, acting as green infrastructures. National wetland strategies make a sound contribution to water resources management, and cooperation ensures the wise use of international resources.


More information

Upload your event on the occasion of World Water Day on the link below:


Download their Factsheets


Watch the video of World Water Day 2017: Are you a waster?

Watch the MedWet Cartoon: Wetlands Provide Priceless Services.

Read the Framework for Action 2016-2030 of MedWet.

MWO 2012_Technical report: Mediterranean Wetlands Outlook 2012