Flood retention reservoir (Beimbach)

The flood retention reservoir at Beimbach was constructed from 1964 to 1967. After damage had occurred, complete refurbishment work and upgrading work was performed between 1990 and 2011. The 173 m long gallery was provided with a steel lining of structural steel, and the 46 m high valve shaft was lined with stainless steel.

Due to progressing damage and serious corrosion, IRS was commissioned with the engineering services for inspecting the facility and identifying a solution for refurbishment by the Water Board of Brettach.

During an on-site inspection, serious corrosion was detected on the gates, guides and the drive chain, which were particularly due to electrolytic corrosion as a consequence of the use of different materials (large surfaces with stainless steel lining). The lack of a coarse rake in the inlet resulted in a considerable accumulation of debris (driftwood) upstream of the sliding gate. The destruction on the gate, the sealing stops in the concrete and the guides had progressed so seriously that repair was no longer possible from an economic perspective.

IRS developed solutions for the refurbishment of the facility. The proposals included the renewal of the sliding gate including the stops and guides, as well as an adaptation of materials to minimise electrochemical corrosion. In addition, it was suggested to replace a part of the drive chain by a pipe in order to avoid vibrations, as well as to install a coarse rake on the inlet.

Scope of planning:
- Review of and commenting on the existing documentation
- On-site inspection and preparation of a damage and inventory survey
- Proposal of solutions for refurbishment (renewal of bottom outlet gate suspension, complete gate refurbishment with modification or replacement, renewal of gate guides, reduction of electrolytic corrosion, coarse rake on inlet structure)
- Preparation of cost estimates