Engineering services for desilting a stormwater retention basin

Summary

The tender concerns comprehensive engineering and specialist planning services for desilting the stormwater retention basin at the Altenholz-Stift heating plant. The basin has an area of approximately 735 m², a volume of 544 m³, and an estimated sediment volume of 165 m³, corresponding to approximately 30.3% sedimentation. The work covers review of existing data, planning the desilting method and water management, sediment sampling and analysis, permit coordination, design, preparation of the desilting works procurement and technical bid evaluation, construction management, site supervision, control surveying, and final documentation. Bids must be submitted by 8 October 2026 at 11:00. Alternative bids are not permitted, price is the only award criterion, and one complete lump-sum bid is required. The documents state different bid-binding end dates: 6 November 2026 in the invitation to bid and 9 November 2026 in the service specification; this should be confirmed with the contracting authority.