Back to the natural balance

The Danish Environmental Protection Agency has set aside a pool of money for climate-­lowland projects in Denmark. This means that municipalities, private plot owners and foundations can apply for subsidy for the extraction of carbon-rich lowland.

Re-establishing natural hydrology
In the past, many lowland areas were drained to enable agricultural cultivation. This practice resulted in oxygenation of the soil, which causes oxygen-consuming bacteria to start breaking down carbon, which then results in the release of CO₂ into the atmosphere. The purpose of climate-lowland projects is to reduce greenhouse gas emissions from carbon-rich lowland soils that were previously used for agriculture. This is achieved by re-establishing natural hydrology. The water level in the lowland area will rise, which will give less oxygen to the soil and with that slower decomposition or complete termination of carbon decomposition.

In addition to CO₂ reduction, the climate-­lowland projects must support the purposes of nature and water environments and other climate purposes. This means that the subsidy scheme has a broad perspective and focuses on synergy with e.g. the Water Framework Directive, the Bird Protection Directive, the Habitat Directive, biodiversity, protected nature types, clean drinking water, outdoor life, organic agriculture and climate adaptation.

Mandatory feasibility studies
Artelia can help prepare the necessary feasibility study, which forms the basis for the Danish Environmental Protection Agency’s decision on whether a project is feasible or not. The feasibility study includes a description of the area and the extraction of soil samples, which are used to assess the potential for retention of CO₂ and nitrogen. The feasibility study must account for whether the project is expected to have sufficient effect for a justification of financial subsidy from the Danish Environmental Protection Agency.

We describe the area and take soil samples so that we can account for how much CO₂ and nutrients can be retained, design engineer Maja Kastbjerg Holm Poulsen explains.

It is not always profitable for the environment to re-establish the natural hydrology, as iron in the dry soil can bind phosphorus, which will be leached into the water environment under increasingly wet conditions. In addition, other and stronger greenhouse gases than CO₂, such as CH₄ (methane) and N₂O (laughing gas), may be emitted from water-saturated and oxygen-free soil. It is therefore crucial to analyse the composition of the soil in the area.

Productive cooperation at Simested Å
In Central Jutland, we are helping a plot owner with a feasibility study at the brook Simested Å.

The feasibility study not only covers the results of a lot of soil samples, but also includes a description of how the project will affect nature and species under Annex IV of the European Habitats Directive (species that are strictly protected throughout the European Union), the water environment, surrounding areas, etc.

Both the plot owner at Simested Å and the Danish Environmental Protection Agency have expressed great satisfaction regarding the collaboration with Artelia on this project. The requirements set by the Danish Environmental Protection Agency have required ongoing dialogue between all three parties to ensure that the feasibility studies considered all requirements.