[et_pb_post_title title="off" meta="off" featured_image="off" admin_label="Improving the ecological status of the river Oker
" _builder_version="4.6.6″ z_index_tablet="500″][et_pb_text admin_label="Improving the ecological status of the river Oker
" _builder_version="4.6.6″ module_alignment="left" custom_padding="||0px||" hover_enabled="0″ z_index_tablet="500″ box_shadow_horizontal_tablet="0px" box_shadow_vertical_tablet="0px" box_shadow_blur_tablet="40px" box_shadow_spread_tablet="0px" sticky_enabled="0″]

Improvement of the ecological status of the Oker

Between the towns of Vienenburg and Schladen in the district of Goslar, Deutsche Bahn replaced a railway overpass (EÜ) over the river Oker with a new construction.

North of Vienenburg, the Oker has a largely natural character. However, the flow behaviour and the structure of the river bed have been anthropogenically altered by a fixed bottom protection in the area of the railway overpass and a bottom drop about 70 m below the bridge.

As part of the planning approval procedure for the new bridge construction, it was decided to dismantle the weir below the EÜ as a compensation measure for the planned intervention in the study area. The redesign provides for the removal of the bottom protection and the replacement of the existing weir by a rough bottom sluice, which ensures the passability for fish and other microorganisms both upstream and downstream. By improving the ecological passability, a development as close to nature as possible should be achieved for the habitat type.

The 62.4 m long rough riverbed channel consists of 13 stone bars, each with two culverts. Several wheel loaders and excavators are currently in use to place the heavy armourstones in the right places. Meanwhile, the Oker is being channelled through a bypass channel. At the beginning of next year, the rough bottom channel will be completed and the Oker will then be diverted back again.

For this project, M&P Ingenieurgesellschaft mbH Hannover was responsible for the environmental impact study with integrated landscape conservation plan for the planning approval procedure of the new bridge construction as well as the design, approval and implementation planning of the invert channel. During the implementation, the environmental and water engineering construction supervision as well as the waste-technical preservation of evidence of the provision areas are also carried out.