Rainwater retention basin for John Deere logistics center

In Zweibrücken, Rhineland-Palatinate, the agricultural machinery manufacturer John Deere produces combine harvesters and self-propelled forage harvesters for the global market. The company has now built a 22,000 m² logistics center right next to its factory. Among other things, a large rainwater retention basin ensures orderly rainwater management on the approximately 3.6-hectare site, which only passes on the precipitation in a restricted manner. For this structure, the planners opted for a construction method with rectangular frame profiles made of reinforced concrete.

The production of combine harvesters and forage harvesters is very parts-intensive - from the smallest screw to the complete engine, all components must be delivered „just in time” to the assembly line. Until now, the John Deere plant in Zweibrück had a large number of internal and external warehouses available for this purpose. The main warehouse was located in Hockenheim, 140 km away. In addition, there were six other warehouse locations. The new logistics center is intended to replace seven warehouses in the future and thus significantly reduce the logistics effort. This could eliminate 1,200 deliveries per year from the main Hockenheim warehouse, which is being closed down. The company ­consequently expects a reduction in CO₂ emissions of around 950 t per year. The drainage of the precipitation on the sealed area, which covers a good 30,000 m², is carried out via a rainwater retention basin.

33 precast frame elements store 1,750 m³ of rainwater

Bernd Hoffmann, site manager of BMS Baumaschinen Mietservice und Abbruch GmbH, who implemented the measure on behalf of Goldbeck International GmbH, explains: „The rectangular underground storage tank consists of 33 precast reinforced concrete elements. Around 6,700 m³ of excavated earth was required to bury the precast elements. The individual components have dimensions of 7 x 3 x 2.6 m.

This results in a total storage volume of 1,750 m³ for the rainwater retention basin. A maximum of 150 liters of rainwater per second enters the basin via the inlet. The lowest element has a float-controlled throttle that constantly feeds 13 liters of rainwater per second to the adjacent Schwarzbach stream via a separate collection pipe. Above the throttle is a DN 800 reinforced concrete pipe as an emergency overflow.“

20 minutes assembly per component

The components were supplied by the Finger-Beton group of companies from its plant in Stockstadt. Assembly was carried out in just three days by Finger‘s own assembly team. Project manager Dipl.-Ing. Holger Rohrmann comments: „In order to guarantee the required retention volume and the throttled discharge, each retention tank is individually planned and manufactured by us. For this purpose, the tanks are designed in the factory according to the required throttled discharge capacity, equipped with the optimum throttling device and prepared for later installation on the construction site. The frame tank constructions are delivered by Finger-Beton as individual elements by semitrailer. After the elements, which weigh approx. 44 t, have been moved by crane, they are assembled. Thanks to a specially developed, uncomplicated two-point clamping system, we only need a total of about 20 minutes per element. A special arrangement of the parts helps to ensure that the permanently elastic connections are made quickly. Because the screw system is on the outside, it remains protected from corrosion. Additional grouting of the joints is therefore not necessary. Immediately after assembly, the finished frame structure is hermetically sealed, immediately leak-proof and could basically be filled directly with water,“ says Holger Rohrmann.

After the new logistics center opens in July 2022, 125 new jobs will be created here. The state-of-the-art drainage system creates optimal conditions for ensuring that future precipitation is properly drained away.