Our technical article on the Zitrone pumping station has been published in the latest issue of DWA’s Korrespondenz Wasserwirtschaft. Together with two strong partners, we investigated the potential effects of shutting down the pumping station in the Märkische Schweiz Nature Park—from hydrological, ecological, and agricultural perspectives.

One Area, Two Conflicting Objectives

Since the 1960s, the Zitrone pumping station has drained a closed depression covering approximately 1.8 square kilometers. The area is predominantly used for arable farming while also forming part of the Märkische Schweiz Special Protection Area. The kettle holes within the area are legally protected biotopes and serve as stepping-stone habitats for amphibians.

Drainage enables continued agricultural use, while the conservation objectives of the protected area call for the restoration of a near-natural water balance. Using a water-balance model in SWAT+, we simulated two scenarios—with and without operation of the pumping station—over the period from 1995 to 2024 and assessed their impacts.

The Results

Groundwater recharge: Without pumping, groundwater recharge increases from around 40 to approximately 60 millimeters per year—equivalent to an additional 32,000 cubic meters annually.
No permanent lake: The permeability of the subsurface is sufficient to allow the water to infiltrate.
Ecology: Longer periods of water retention in the kettle holes and Lake Zitrone—a benefit for amphibians and bird species such as the common crane, spotted crake, and common snipe.
Agriculture: In around 69% of the years analyzed, there would have been no significant inundation. Only two out of 29 years would have been critical.

Applicable to More Than 250 Sites

The methodology can be applied to other pumping station sites with comparable conditions. In Brandenburg alone, the state authorities are aware of more than 250 pumping stations—indicating considerable potential for water retention across the landscape, with synergies for nature conservation, climate adaptation, and the objectives of the EU Water Framework Directive.

Strom, A.; Spill, C.; Schubert, K.; Krähling, J.; Beisecker, R.; Steinbrecher, G. (2026): Modeling Water Retention with SWAT+ and Integrated Impact Analysis for an Inland Catchment with Pumping Station Operation. Korrespondenz Wasserwirtschaft, 19 (8), pp. 443–450. DOI: 10.3243/kwe2026.08.003

→ Read the technical article as a PDF

The article was produced in collaboration with Ingenieurbüro für Ökologie und Landwirtschaft (IfÖL) and BÖF-naturkultur for the Märkische Schweiz Nature Park of the Brandenburg State Office for the Environment.