How to restore natural sponges

Unlocking the power of wetlands to create climate and water resilient landscapes

Finding the right conditions for Natural Sponges

A formula for success in Europe

There are many variables that can make soil a potential natural sponge. A good scenario can be found in the middle mountains, where there are gentle slopes that can retain water and minimise the runoff effects of high precipitation rates.

Several of Europe’s major rivers such as the Rhine, Meuse, Duero, Elbe and Po originate in middle mountain regions. The upper catchments of these rivers are characterised by elevations of 200 – 1200 metres, high amounts of precipitation and valleys with gentle slopes of less than 10 per cent.

Finding the right conditions for Natural Sponges

A formula for success in Europe

There are many variables that can make soil a potential natural sponge. A good scenario can be found in the middle mountains, where there are gentle slopes that can retain water and minimise the runoff effects of high precipitation rates.

Several of Europe’s major rivers such as the Rhine, Meuse, Duero, Elbe and Po originate in middle mountain regions. The upper catchments of these rivers are characterised by elevations of 200 – 1200 metres, high amounts of precipitation and valleys with gentle slopes of less than 10 per cent.

Upper catchments are “just right” for natural sponges

The valley bottoms in middle mountain upper catchments collect water from the surrounding hills and therefore have a large regulatory effect on how fast water flows into the smaller tributary streams.

Currently, the widespread drainage of these areas for agriculture and forestry speeds water downstream, contributing to higher peaks in floods and lower base flows in dry periods.

Restoring the natural sponge capacity of soils in upper catchments to capture and retain water – before it flows into streams –delays runoff from larger areas such as slopes and plateaus and provides multiple benefits, including flood mitigation, drought prevention and the filtration of pollutants.

BeforeAfter

Slow the flow

A quick guide to retaining and storing water in the landscape

Block drainage channels that speed up surface water
Intercept rain with
rough vegetation
Ensure water that
reaches the ground
can infiltrate
Hold water in soils and wetlands as long as possible, and reinfiltrate from paved surfaces, fields and slopes
Slow water that comes to the surface in valley floors with vegetation

Slowing down water streams

A step-by-step plan to retain and store water

Block drainage channels that speed up surface water
Intercept rain with
rough vegetation
Ensure water that
reaches the ground
can infiltrate
Hold water in soils and wetlands as long as possible, and reinfiltrate from paved surfaces, fields and slopes
Slow water that comes to the surface in valley floors with vegetation

Measurable benefits for people and nature

Our research shows multiple advantages for people, biodiversity, climate and water

Peak flow reduction
Up to 30% lower peak flows of water during floods
Increased base flows
Up to 20% higher flows of water in dry periods
Improved water quality
Substantial reductions in nitrogen and phosphorus at the local and catchment levels
CO2 reduction
Reduces oxidation of the existing carbon stock and increases the potential for carbon capture and storage
Restoring healthy nature
Supports diverse and endangered habitats for animals and plants