Largely Untapped, Nature Can Improve Water Quality for Cities

City and utility leaders who embrace both natural and engineered water infrastructure will not only meet future water demand; they will reshape our planet’s landscape for the better.

In less than 20 years from now, nearly three-quarters of all people living on the planet will live in urban areas. This is uncharted territory for humanity and the pace of change, the speed with which we are urbanising and changing our lifestyles, is unprecedented. The challenges this demographic revolution presents can seem overwhelming, but it also represents an enormous opportunity to get it right, particularly when it comes to water management.

We have an opportunity to deliver smart water and sanitation solutions focused on concentrated urban populations, particularly through increasing water quality and urban resilience by integrating natural solutions with built infrastructure. Cities must look beyond their municipal boundaries and work alongside other water users to apply natural solutions to the watershed. To do so, requires us to understand the current situation and to project what the future will look like.

The Urban Water Blueprint, a new report published today by The Nature Conservatory in partnership with the International Water Association and C40 Cities Climate Leadership Group is a first of its kind: an in-depth analysis of the state of water for over 500 large and medium sized cities, including the 100 largest cities in the world, representing nearly 1 billion people. Collectively, these cities represent $21.8 trillion in economic activity, or 48 percent of the global GDP.

The report is piercing in its conclusions: one in four cities worldwide is facing water stress today; one in three of the largest 100 cities in the world are currently in water stress; and hundreds of millions of people are drawing their water from sources of low quality due to high sediment or nutrient loading.

Scarce water supplies and polluted waterways are forcing cities to look for clean water beyond their boundaries. The largest 100 cities in the world move 3.2 million cubic meters of water every day more than 5,700 kilometers (3,500 miles or roughly the distance between New York and Paris) to overcome local water shortages or pollution. This is an expensive solution.

Cities, and utilities, spend nearly $90 billion building infrastructure that delivers and treats water annually, but nature also plays a vital role in water delivery and treatment, one that has gone largely untapped. Natural solutions have the potential to save cities $890 million a year in water treatment costs.

For instance, the 100 largest cities occupy less than one percent of the planet’s land area; however their source watersheds cover over 12 percent. That’s an area of land roughly the size of Russia – 1.7 billion hectares that collects filters and transports water to nearly a billion people before reaching man-made infrastructure.

To get the greatest return on investment, cities and utilities should look to apply natural solutions to the watershed. Protecting water before it reaches cities can be cheaper and more efficient than treating it after it’s been polluted, and there’s a lot of opportunity to improve water quality for cities by improving farming practices. One in four cities that apply natural solutions to their watersheds could realize a positive return on investment based solely on cost savings from avoided water treatment.

If we act and invest now in natural solutions, including forest protection, reforestation, stream bank restoration, improved agricultural practices and forest fuel reduction, more than 700 million people could receive better quality water.

These solutions are still relatively new to many utilities and cities, and they will require them to invest in areas outside of their jurisdictional boundaries. This is a new frame for water management that will require city leaders to think beyond their intake point and align with other water users in the region. Perhaps more importantly, it will require urban planners, utility managers, city and state politicians, industry and agriculture to break down the artificial barriers preventing them from cooperating and collaborating to make this a reality.

Through its thematic programmes, specifically Basins of the Future and Cities of the Future, IWA is providing a platform to bring these constituencies together. Strengthening the connection of cities to their basins through the development and implementation of frameworks and equipping water utilities as a pivotal player in making the various inter-dependencies work.


An Executive Summary of the report can be found here

The full report can be downloaded here

For more information visit the Urban Water Blueprint website