Planting trees to harvest drinking water

Among the threats to environmental security at international and national level, the issue of drinking water scarcity is a prominent one. We have recently accompanied a community-powered project in Germany that aims to tackle this problem at the root!

Water is life, but it is not endless

Water is the unique medium of the biosphere, the source of life, a prerequisite for development, the solvent and carrier of pollutants – cliché statements, but true. For a long time, humans considered many natural resources like water limitless. They assumed that there is an endless supply of cheap and clean water, supporting continuous economic growth.

Today we think differently: water, among several other natural resources, is a limited, fragile medium with economic value. This big shift started in the 1960s. Since then, analysts have been arguing that the biggest problems we face are excessive water demand combined with limited supply, floods, erosion, water pollution, the cost-benefit ratio of hydro power, and the effects of climate change.

In the last decades, the use of water per capita has nearly doubled. It is estimated to have increased by around 80% between 1980 and 2000. The scarcity of drinking water is one of the most critical problems that we are facing.

Since July 28, 2010, access to clean drinking water and basic sanitation have been included among the human rights (Bolivia’s motion at the UN General Assembly). But there are more and more supply gaps in different regions, which in turn cause shortages in food production for the people. Currently, about two thirds of the world’s countries face water shortages and among EU Member States, Belgium is already an importer of drinking water.

Drinking water forests

On our first stop in the Hessen region of Germany, we accompanied a very interesting project, dealing with this issue. In recent years, the European spruce bark beetle has had a devastating impact on the forests of Germany, leading to massive forest die backs across the country. Damages have also massively hit the forests of the little town Wehrheim, which is managed by Hessen Forst (Hessen State Forestry). However, local foresters have seized the opportunity and joined forces with the NGO Trinkwasserwald to work together with communities to build resilient forest ecosystems for the future.

The NGO Trinkwasserwald has been promoting site-appropriate silviculture throughout Germany since 1995 in order to ensure better drinking water quality and protect biodiversity in the long term. Supported by several private and corporate donors, tree sponsors and volunteer planters, up to now Trinkwasserwald has planted about 6,000 ha of “drinking water forests” across Germany and thus generated about 4 billion additional liters of groundwater of high quality. This amount of groundwater secures the lifetime drinking water supply of over 5 million people for generations to come.

Upon our morning arrival at the planting site, we met the main organisers of the action. The area was secured and well-prepared by foresters from Hessen State Forestry. Enabled by Trinkwasserwald, the volunteers for the two-day event were employees of the Deutsche Bank and their families. Deutsche Bank also donated over 4000 seedlings of wild cherry and hornbeam to be planted in the prepared area. After a full week of rain and cool temperatures, we expected that not more than a handful of volunteers would show up. However, to our biggest surprise, as the morning went on, more and more people of all generations appeared in full planting gear, ready to get their hands dirty. They were all here to restore and preserve water quality.

Speaking to the executive chairman of Trinkwasserwald, Alexander Pillath, and project manager Katharina Meyer-Schulz, the name ‘Trinkwasserwald’ became immediately clear. Katharina explained that compared to coniferous monocultures, mixed deciduous forests supply significantly more groundwater. The national average is 800,000 liters per year and hectare. And there is way more to uncover when we look at the connection between our forests and water supply, its history, present and future.

Forests and water

Before human intervention, the native forest consisted of almost 99 % mixed, species-rich deciduous forests and only one percent coniferous forest. It now consists of around 65 % coniferous forest and only 35 % mixed deciduous forest. Globally, forests once covered 34 % of the earth, but they now cover only 26 %. Currently, about another 20,000 ha of natural forest are being cut down every day worldwide.

Groundwater is formed from fog, rain, snow and hail. On open fields, the water usually runs off quickly. Forest provides an area for water collection and infiltration. However, different types of forests, in terms of groundwater formation, behave very differently. The water quality and the so-called groundwater infiltration are significantly lower under the coniferous trees than under deciduous trees. This is partly due to the fact that conifers retain their needles even in winter, which means that water sticks to this surface and evaporates into the atmosphere instead of falling to the ground and seeping away as groundwater.

In mixed deciduous forests, on the other hand, significantly more water seeps into the forest ground: the trees do not bear leaves in winter and rain falls directly on the ground. The quality of the groundwater is also significantly better, which is related to the more favourable humus buildup under deciduous forests.

But is water shortage even an issue in Germany?

The answer is yes! As clean drinking water is only produced in vital, natural and intact landscapes, these landscapes should be protected or increasingly created to ensure sufficient water production.

The quality of drinking water available to future generations is our decision today. Overexploitation of nature, intensive agriculture and coniferous monocultures reduce the natural recharge of good quality groundwater. In addition, inadequate water protection, resulting in the contamination of streams, rivers and lakes, will continue to have an effect for a long time to come. Many influencing factors, such as climate change, population growth, pollution, unsustainable resource management, consumerist behaviour, and others will negatively affect the groundwater of tomorrow. 

Local communities are the biggest allies

Tree planting is perhaps the most crowd-pulling climate change mitigation approach, and if done right, it has many benefits. Restored, healthy forest ecosystems support biodiversity and carbon sequestration and provide a range of essential ecosystem services, such as clean water.

What proves to be crucial time after time is that surrounding communities are treated as key players in nature conservation projects, such as reforestation. As obvious as it may seem, one of the most common reasons for unsuccessful reforestation projects is that this is ignored. Particularly in large-scale forest restoration projects, it is essential to involve a wide range of stakeholders at the planning table to ensure that all aspects are taken into account, from the livelihoods of local people, through the protection of biodiversity, watershed and ecosystem services, to the conservation of the ecosystem’s carbon sequestration capacity. Only in this way can the long-term sustainability of the project be ensured. In smaller-scale reforestation projects such as the activities of Trinkwasserwald, working with individuals of all generations also benefits the community by increasing knowledge, understanding and engagement rate.

As for our day, grey skies and occasional rainfalls (accompanied by hail) failed to dampen volunteer enthusiasm. After a full day of work, the sense of community grew palpably stronger. And with that, all participants could return home knowing that every commitment to the forest, globally and locally, is a valuable contribution to our planet.

A special thanks goes to Tobias Drisch, a friend of Jonas and young forester at Hessen Forst. He invited us to join the tree planting and showed us some of the forest after the planting (stay tuned to learn about that).