By Giulio Boccaletti and Lynn Scarlett of The Nature Conservancy, an IUCN member.
While the negotiations at the UN climate conference (COP21) in Paris have been deemed successful on many fronts, we are already witnessing the impacts of climate change on our most critical resource – water.
Recent floods in India, Vietnam, the United Kingdom and Ireland have driven thousands from their homes, interrupted electricity supplies and transport, caused huge damage to property and disrupted economic activity. Other places such as Somaliland and Namibia are in the grip of desperate droughts, stunting crops and starving livestock. Water cannot be addressed on the sidelines: it is inherently part of each action that will be taken as a result of the negotiations. And working with nature is at the heart of the solution to the water crisis.
Half the world’s population already suffers water shortages, and more than 21 million people are victims of flooding each year. And yet in the coming decades, climatic events will become even more extreme and more unpredictable.
For millennia, nature has provided protection from natural disasters. Forests contain water and stem hillside flows; floodplains give space for rivers to overflow, while creating highly fertile farmland; bends, rocks and islands slow down rivers, reducing the risk of floods.
But in more modern times, population growth and economic activity have eroded these natural defences. Ecosystems have been degraded – denuding forests, damaging environments for wildlife such as fish, intervening to ‘improve’ rivers and wetlands – with serious consequences for people and nature alike.
These mistakes were often made with good intentions and the state of knowledge of their time. But learning from the past is essential to avoid repeating the same mistakes and to reverse them where possible. Even more important, if we are to secure the quantity and quality of water the world needs, we must understand how to work with nature on a scale large enough to effectively address the impact of climate change on water. Indeed, the Paris Pact on water and climate change adaptation announced at COP21 looks to river-basin scales for addressing climate and water management.
Every year, cities spend nearly US$ 90 billion on infrastructure that delivers and treats water. Only a tiny portion of this expenditure is dedicated to improving the services nature provides for water. But experience with projects in many countries shows that the potential for harnessing and restoring nature’s functions is huge.
A leading example is the programme for the Magdalena River in Colombia. The river is about 1,500 kilometres long, and its basin covers almost a quarter of Colombia. A partnership between the authorities, private sector and NGOs aims to balance the claims of navigation, flood control and nature conservation. Approaches being taken include analysing the most important areas for freshwater conservation and creating a basin-wide hydrological model. Improving dam management is a key part of the Magdalena programme.
A major floodplain restoration effort has taken place at Mollicy Farms, a former floodplain forest on the Ouachita River in Louisiana. The river is part of the Mississippi River system, and the floodplain was cut off from the Ouachita by a levee in the 1960s. Replanting the area and allowing the river to flood it aims to alleviate downstream flooding, improve water quality by reducing the sediment and nutrient content, and restore fish and wildlife habitats.
Financing conservation-based projects can be difficult while there is an almost instinctive preference among engineers and governments for built rather than natural infrastructure. One answer is water funds. More than 30 water funds are in operation from Africa to Central America. They are a mechanism for downstream water users to finance upstream conservation through techniques such as reforestation, riverbank repair, floodplain restoration and forest fire fuel reduction.
An example is the Nairobi Water Fund bringing together Nairobi’s water utility, farmers, NGOs and investors to restore the Upper Tana River, which supplies the bulk of the city’s water. Overall, US$ 10 million will be invested in conservation activities in the area and it’s expected to return US$ 21.5 million in benefits over 30 years — a great return on investment for the people of Nairobi and communities throughout the watershed.
While nature can support our needs for clean water and flood protection, it’s important for us to understand nature’s water needs, too. Droughts occur when people demand more from water supplies than the naturally fluctuating hydrological cycle allows. Groundwater is often an essential component of water availability, even in regions whose surface is normally arid. This is true of California, which depends heavily on groundwater in dry years and is suffering the worst drought in a very long time. Understanding the amount of water available, and adjusting extraction rates accordingly, is vital for storing water in wet years and controlling use in dry years. California is waking up to this fundamental truth.
We are experiencing climate change through water, but we have answers at hand. Working with nature can reduce floods just as it can reduce droughts. Experience shows that we can work with nature on a scale which will protect water resources and habitats for generations to come. We should not wait for climate change to wreak more damage on our most critical resource before enlisting nature’s aid.
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