Soil erosion

In recent years, heavy rainfall events in the Oberbergischer Kreis have significantly increased. They occur more frequently and are often more intense. This leads to increased soil erosion during the summer months. The washed-away soil accumulates not only at the foot of slopes or in field margins but increasingly finds its way into water bodies, roads, streets, and built-up areas.

The risk of soil erosion increases especially due to: 

• bare and steep arable land 

• the conversion of grassland into arable land on slopes 

• crops with large row spacing and late ground cover, such as corn 

• intensive soil cultivation that damages soil structure and compacts the soil. 

Soil erosion has far-reaching consequences. Valuable humus and clay components are lost, soil fertility decreases, and yields may decline.

Legal foundations
Protection against harmful soil changes due to erosion is regulated at the federal and state levels. Relevant regulations include:

• the Federal Soil Protection Act (BBodSchG), 

• the Federal Soil Protection and Contaminated Sites Ordinance (BBodSchV), 

• the North Rhine-Westphalia State Soil Protection Act (LBodSchG NRW).

Tasks of the Lower Soil Protection Authority

The Lower Soil Protection Authority records erosion damage, reviews damage reports, and assesses erosion risk. It uses various technical resources such as maps, calculations, and mapping guidelines. 
How susceptible a soil is to water erosion depends on its grain size, coarse soil content, and humus content. These factors are incorporated into the calculation of erosion risk based on the Universal Soil Loss Equation (USLE). 
The Geological Service NRW provides the erodibility of the topsoil in a digital map:
Map of Topsoil Erodibility
Additionally, a "Map of Potential Erosion Risk" was created for the district based on the USLE. It classifies the risk into five categories from "very low" to "very high" and is used for official evaluations. In 2010, about 15% of the agricultural land in the Oberbergischer Kreis had a high to very high potential erosion risk.

Guidelines for Agricultural Enterprises

Farmers who cultivate land prone to erosion and wish to receive EU agricultural subsidies must comply with the requirements of the Conditionality Regulation
Conditionality Regulation (GAPKondV).
The legally binding classification of erosion risk is determined through the State Erosion Framework. This framework specifies which areas are subject to the requirements of the GAP Conditionality Regulation.
The Geological Service NRW provides the following map:
State Erosion Framework NRW (GAPKondV)

Grassland Conversion

Anyone wishing to convert permanent grassland into arable land must first submit an exceptional application to the responsible district office of the Chamber of Agriculture North Rhine-Westphalia:
Chamber of Agriculture NRW – District Office Oberbergischer Kreis, Rheinisch-Bergischer Kreis, and Mettmann 
During the process, the Chamber of Agriculture involves the Lower Nature Conservation Authority, which obtains a soil protection expert opinion. The "Map of Potential Erosion Risk" serves as the basis for evaluating the impacts of the planned grassland conversion.