Hochwasserschutzverband Innerste Awards €12.34M Flood Retention Basin Contract to Gebr. Gropengießer GmbH

The Hochwasserschutzverband Innerste (Innerste Flood Protection Association) has awarded a contract for the construction of a controlled flood retention basin east of Bornhausen to Gebr. Gropengießer GmbH. The €12.34 million contract covers the construction of a dam with a volume of 180,000 m³, a controlled reinforced concrete culvert with three sluice gates, and associated infrastructure. The project runs for 3 years.

Introduction

The Hochwasserschutzverband Innerste (Innerste Flood Protection Association), a public-law body controlled by a local authority, has conducted an open procedure for the construction of a controlled flood retention basin east of Bornhausen in the Goslar district of Lower Saxony, Germany. The project aims to address the increasing occurrence of heavy rainfall events and protect the towns of Rhüden and Bornhausen from flooding.

The contract, valued at €12,343,124.58, has been awarded to Gebr. Gropengießer GmbH, a small German construction company based in Wulften. The contract runs for 3 years and includes the construction of a dam with a storage volume of 810,000 m³, a controlled reinforced concrete culvert with three sluice gates, and associated infrastructure.

Ten tenders were received, with five from SMEs. No subcontracting was declared. The procurement is not covered by the GPA.

Why This Contract Matters

This contract ensures the construction of critical flood protection infrastructure to protect the communities of Rhüden and Bornhausen from increasingly frequent heavy rainfall events.

This contract matters because it:

• Protects communities: Prevents flooding in Rhüden and Bornhausen
• Significant value: €12,343,124.58
• Long-term commitment: 3-year construction period
• Large scale: 810,000 m³ storage volume on 25 hectares
• Comprehensive scope: Dam, culvert, sluice gates, access roads
• SME participation: Winner is a small enterprise
• Strong competition: 10 tenders received

Contract Timeline

• Previous notice: 258289-2026
• Winner chosen: 25 August 2026
• Contract concluded: 7 September 2026
• Contract duration: 3 years
• Notice published: 9 September 2026 (OJ S 174/2026)

Contract Overview

The Hochwasserschutzverband Innerste conducted an open procedure under the standard regime, governed by EU Directive 2014/24/EU and the German VOB/A-EU (Construction Contract Procedures).

Key features include:

• Single lot: One contract covering all construction works
• Awarded value: €12,343,124.58
• Duration: 3 years
• No framework agreement: Direct works contract
• Evaluation: Most economically advantageous tender (price focus)
• Winner: Gebr. Gropengießer GmbH (small enterprise)
• No subcontracting declared
• No EU funding
• Not covered by GPA

Key Contract Details

Detail	Information
Contracting authority	Hochwasserschutzverband Innerste
Contract title	Bau eines gesteuerten Hochwasserrückhaltebeckens östlich von Bornhausen
Main CPV	45246000 River regulation and flood control works
Additional CPVs	45247200, 45000000, 45240000, 45247000, 45246400
Procedure type	Open procedure (standard regime)
Legal basis	EU Directive 2014/24/EU; German VOB/A-EU
Awarded value (EUR)	€12,343,124.58
Number of lots	1
Contract duration	3 years
EU funding	None
Covered by GPA	No
Evaluation criteria	Most economically advantageous tender
Location	Bornhausen, Goslar, Germany (NUTS: DE916)
Subcontracting	No
Number of tenders	10
SME participation	5 (including winner)

Project Scope – Flood Retention Basin

• Purpose: Controlled flood retention basin to reduce runoff of the Schildau river before it flows into the Nette
• Storage volume: 810,000 m³
• Area: Approximately 25 hectares
• Location: East of Bornhausen on the Schildau
• Beneficiaries: Protects Rhüden and Bornhausen from flooding

Dam Structure

• Type: Main embankment dam
• Height: Approximately 8.0 metres (average)
• Length: Approximately 380 metres
• Slope: 1:5
• Volume: Approximately 180,000 m³ (including sealing core and toe drain)

Reinforced Concrete Culvert Structure

• Type: Traversable reinforced concrete culvert
• Sluice gates: Three controllable sluice gate systems
• Flood overflow threshold: Included
• Clear width: 11.3 metres between side walls
• Concrete floor length: Approximately 30 to 50 metres
• Temporary watercourse diversion: Required during construction

Additional Works

• Operations building: Construction of an operations building
• Farm track elevation: Elevation of the farm track north of the basin
• Access roads: Construction of accompanying farm tracks to the dam structure
• Passing bays: Construction of two passing bays
• Coarse screen: Installation of a coarse screen
• Temporary construction roads: Construction of temporary access roads

Alternative Tenders (Nebenangebote)

• Permitted: Alternative tenders are permitted in conjunction with a main tender
• Scope: Exclusively for the "construction of the supporting body of the dam structure"
• Requirements: Minimum requirements and further information in Annex "2026_06_05 Information Nebenangebote"

About the Contracting Authority

Hochwasserschutzverband Innerste is a public-law body (water association) controlled by a local authority, responsible for flood protection in the Innerste river basin in Lower Saxony, Germany.

About the Winning Supplier

Gebr. Gropengießer GmbH is a small German construction company based in Wulften, Lower Saxony, specialising in civil engineering and construction works.

• Size: Small enterprise
• Headquarters: Am Bahnhof 2, Wulften, Germany (NUTS: DE91C)
• Registration number: DE177 012 806
• Beneficial owner: Germany
• Specialisation: Civil engineering and construction
• Subcontracting: No

Procurement Analysis

• Procedure: Open procedure under the standard regime, governed by EU Directive 2014/24/EU and German VOB/A-EU.
• Competition: Ten tenders were received (all electronic).
• SME participation: Five tenders from SMEs (3 medium, 2 small); winner is a small enterprise.
• Subcontracting: No subcontracting was declared.
• No EU funding: The procurement was not financed with EU funds.
• Not covered by GPA: The procurement is not covered by the GPA.
• No framework agreement: This is a direct works contract.
• No dynamic purchasing system used.
• Accelerated procedure: No.
• Strategic procurement: No strategic objectives specified.
• Review body: Vergabekammer Niedersachsen.

Additional Procurement Facts

• The contract is not covered by the GPA.
• No EU funds were used for this procurement.
• The contract value is €12,343,124.58.
• The contract duration is 3 years.
• Ten tenders were received (strong competition).
• Five tenders were from SMEs.
• The winner is a small enterprise.
• No subcontracting was declared.
• Alternative tenders are permitted for the dam supporting body.
• No inadmissible tenders were recorded.
• No abnormally low price tenders were recorded.
• Review deadlines are governed by German GWB provisions.

Market & Industry Perspective

The German flood protection and civil engineering market is competitive, with a mix of large construction groups and regional SMEs. The increasing frequency of heavy rainfall events has driven investment in flood protection infrastructure.

Key trends in this market include:

• Flood protection: Growing investment in flood retention infrastructure
• Price focus: Most economically advantageous tender
• SME participation: SMEs compete effectively
• Regional contractors: Local and regional companies dominate
• Long-term projects: 3-year construction timelines

Economic Significance

At €12.34 million, this contract represents a significant investment in flood protection infrastructure for the Innerste region. The contract will:

• Protect communities: Prevent flooding in Rhüden and Bornhausen
• Support SME: Gebr. Gropengießer GmbH is a small enterprise
• Create employment: Work for construction staff
• Provide long-term value: 810,000 m³ storage capacity
• Enable climate adaptation: Address increasing heavy rainfall events

Future Procurement Opportunities

With this contract now in place, future opportunities include:

• Related works: Additional flood protection infrastructure
• Subcontracting: Potential opportunities (none declared)
• Maintenance: Ongoing maintenance of the retention basin
• Other German regions: Similar flood protection procurements

Opportunities for Suppliers

While this contract is awarded, opportunities remain for civil engineering and construction companies:

• Subcontracting: Potential opportunities with Gebr. Gropengießer GmbH
• Related projects: Other flood protection works
• Other German regions: Similar flood retention procurements
• Maintenance: Ongoing maintenance of the retention basin

What Businesses Should Watch

• Hochwasserschutzverband Innerste's future procurement notices
• Other German flood protection tenders
• Civil engineering market trends
• Changes to German procurement regulations

GermanyTenders Procurement Intelligence

This flood retention basin contract is a notable example of German public sector flood protection procurement. Several features stand out:

• Scale: €12.34M over 3 years
• Competition: 10 tenders received
• SME winner: Gebr. Gropengießer is a small enterprise
• Not GPA covered: Exempt from GPA
• Alternative tenders: Permitted for specific scope
• Long-term: 3-year construction timeline

For suppliers, this procurement highlights the importance of:

• Competitive pricing: Most economically advantageous tender
• Civil engineering expertise: Dam and flood protection construction
• SME status: SMEs can compete effectively
• Regional presence: Being established in Lower Saxony
• Alternative tenders: Ability to offer variants for specific scopes

Supplier Takeaways

• Offer competitive pricing – most economically advantageous tender
• Build civil engineering expertise in flood protection
• Consider regional presence in Lower Saxony
• Prepare alternative tenders where permitted
• Monitor German flood protection procurement opportunities

Key Takeaways

• Hochwasserschutzverband Innerste awarded a €12.34M flood retention basin contract
• Winner: Gebr. Gropengießer GmbH (small enterprise)
• Project: 810,000 m³ basin with 180,000 m³ dam
• Duration: 3 years
• Evaluation: Most economically advantageous tender
• 10 tenders received
• No subcontracting declared
• Not covered by GPA

Conclusion

This flood retention basin contract ensures the construction of critical flood protection infrastructure to protect the communities of Rhüden and Bornhausen from increasingly frequent heavy rainfall events. By awarding the contract to Gebr. Gropengießer GmbH, a small enterprise, the Hochwasserschutzverband Innerste supports local business while ensuring competitive pricing.

The strong competition (10 tenders) demonstrates the attractiveness of flood protection projects to the German construction market. The inclusion of alternative tenders for the dam supporting body provides flexibility for innovative solutions.

For suppliers, this procurement highlights the importance of competitive pricing, civil engineering expertise, and regional presence in winning German flood protection contracts.

Frequently Asked Questions

Q: What is the Hochwasserschutzverband Innerste?

Ans: A public-law body (water association) responsible for flood protection in the Innerste river basin in Lower Saxony, Germany.

Q: What is the value of the contract?

Ans: €12,343,124.58.

Q: Who is the winner?

Ans: Gebr. Gropengießer GmbH, a small German construction company based in Wulften, Lower Saxony.

Q: What is being built?

Ans: A controlled flood retention basin with a storage volume of 810,000 m³, including a dam (180,000 m³), reinforced concrete culvert with three sluice gates, operations building, and access roads.

Q: What were the evaluation criteria?

Ans: Most economically advantageous tender (price focus).

Q: How long is the contract?

Ans: 3 years.

Q: How many tenders were received?

Ans: Ten tenders were received.

Q: Is this contract funded by the EU?

Ans: No, the procurement is not financed with EU funds.

Q: Is the contract covered by the GPA?

Ans: No.

Q: What is the review body?

Ans: Vergabekammer Niedersachsen.

Q: Are alternative tenders permitted?

Ans: Yes, for the "construction of the supporting body of the dam structure".

Source: EU Official Journal, Contract Award Notice 621963-2026, OJ S 174/2026, published 9 September 2026.

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