How the market for sewer services, sewer rehabilitation and specialist foundation engineering is structured
The market covers services related to the inspection, cleaning, maintenance, repair and renewal of underground infrastructure, above all sewers and pipelines. Germany's public sewer network alone is around 619,000 km long. On top of this come private property drainage systems, industrial networks and the pipes of the housing sector. Within the market, three segments with different business models can be distinguished.
Sewer services. Sewer service companies clean, inspect and maintain sewers, manholes, separators and house connections at regular intervals. Typical services include high-pressure jetting, CCTV inspection and leak testing. Clients are municipalities and wastewater utilities, industry, the housing sector and private owners. The business is recurring and often runs on framework agreements. Capital is tied up mainly in the fleet of vacuum and jetting trucks and in inspection equipment.
Sewer rehabilitation. Rehabilitation companies repair, renovate and renew existing pipes. Renovation is dominated by trenchless methods, such as the cured-in-place pipe liner, which is pulled into the old pipe and cured there, and robots for localised repairs. The cost advantage over open-cut construction is considerable. Hannover Finanz puts the German market for trenchless sewer rehabilitation at around EUR 1.3 billion, growing at about 5.6% a year, with around 86% of volume coming from public clients.
Specialist foundation engineering. Specialist foundation engineering covers technically demanding work in the ground: excavation pits and shoring, sheet piling, bored piles, foundations and ground improvement, as well as the trenchless installation of new pipes by pipe jacking or microtunnelling. The business is project-driven, equipment-intensive and closely linked to construction companies, rail and infrastructure projects.
From an M&A perspective, this distinction is central. Sewer services generate recurring revenue, sewer rehabilitation follows the rehabilitation programmes of network operators, and specialist foundation engineering follows the project business. Buyers value the three business models accordingly. Our page on the Construction & Infrastructure sector gives an overview of the environment.
Which developments are structurally driving demand for sewer rehabilitation
Three developments are shifting demand, regardless of whether anyone wants to buy or sell.
Ageing networks and growing rehabilitation needs. The public sewer network grew from around 357,000 km in 1991 to around 619,000 km in 2022. According to the German Association of Energy and Water Industries (BDEW), the investments of this expansion phase are already triggering reinvestment that will continue to increase. For North Rhine-Westphalia, the state environmental agency notes that the network was largely built over the past 100 years and that the main task in future lies in rehabilitation rather than new construction. Experts there estimate damage rates of 50 to 70% for house connection pipes. For providers, this means a long pipeline that starts with inspection and ends with rehabilitation.
High investment needs with predictable financing. A study commissioned by the Association of Local Utilities (VKU) puts the investment needs of water supply and wastewater disposal up to 2045 at around EUR 800 billion, around 65% of which relates to wastewater. Instead of the current EUR 10 billion or so per year, an average of around EUR 40 billion a year would be needed. In the KfW Municipal Panel 2026, the investment backlog perceived by municipalities reached a new high of EUR 231.2 billion, of which EUR 10.4 billion relates to water supply and wastewater disposal. Because wastewater disposal is financed through fees and charges paid by connected households and businesses, demand depends less on the state of municipal budgets than it does for schools or roads. For service providers, this means that orders come from rehabilitation programmes and framework agreements that run over several years.
Stricter environmental requirements. The recast EU Urban Wastewater Treatment Directive (EU) 2024/3019 has applied since 1 January 2025 and must be transposed into German law by 31 July 2027. For agglomerations of more than 100,000 population equivalents, it requires an integrated urban wastewater management plan by the end of 2033, and for areas of between 10,000 and 100,000 population equivalents, based on a risk-based approach, by the end of 2039. The plans assess the effects on downstream waters and on use for public water supply. They must be updated every six years. For combined sewer overflows, the directive sets a non-binding indicative target of 2% of the annual collected urban wastewater load, calculated under dry weather conditions. According to BDEW, values of 3 to 5% may also be appropriate depending on local conditions. Anyone drawing up such a plan needs to know precisely how their network behaves in rain and must remedy weak points in a targeted way. This is likely to create additional demand for inspection, sewer rehabilitation and stormwater retention.
Why the market for sewer services and sewer rehabilitation is beginning to consolidate
Fragmented providers are meeting clients who demand larger network sections, end-to-end documentation and services from a single source. That is the core of the consolidation logic. Added to this is the capital requirement: rehabilitation units, sewer robots and inspection vehicles need constant renewal. For a company with a single owner, every new unit becomes a personal investment decision.
At the same time, many companies face a generational change. Across German SMEs, 57% of owners are aged 55 or older. Mergers resolve both bottlenecks at once: they spread investment across a larger base, create development paths for skilled staff and provide an answer to the succession question.
Recent transactions show how this works in practice:
- May 2025: ZÜBLIN, part of the STRABAG Group, acquires the Austrian subsidiary of BAUER Spezialtiefbau, which focuses on pile foundations. BAUER is withdrawing from specialist foundation engineering in Austria for strategic reasons.
- September 2025: WOLFF & MÜLLER acquires a 50% stake in HÄRING Spezialtiefbau and its sister company SGS. HÄRING specialises in sheet piling and pile driving, has a strong position in rail construction and generated revenue of almost EUR 20 million in 2024.
- November 2025: Hannover Finanz acquires a majority stake in Rohrsanierung Jensen from Brügge (around 110 employees) and shortly afterwards Katec Kanaltechnik from Jünkerath. The two trenchless sewer rehabilitation specialists form a national platform, keep their brands and are set to grow through further acquisitions. At Katec, the founder thereby resolves his succession after 28 years.
- June 2026: The Swiss Kanalservice Gruppe, owned by funds advised by Ufenau Capital Partners, combines with the Spanish Grupo SASTI. The group operates in seven countries, employs more than 2,200 people and generates revenue of over EUR 350 million. The accompanying refinancing is intended to support the group's buy-and-build strategy going forward.
Four transactions in just over a year, two types of buyer, one common pattern: buyers acquire companies with their own equipment, well-established teams and solid client relationships that fit into a larger group as a platform or as an add-on.
Who buys companies in sewer services, sewer rehabilitation and specialist foundation engineering
Two buyer groups shape the market. Their motives differ, and anyone wishing to position their company strategically should know both.
Financial investors and the groups they back. They pursue buy-and-build, the step-by-step acquisition of specialist providers to form a larger group. It starts with a platform, a larger and professionally organised company. Add-ons follow: smaller providers that add a region, a method or a client group. The market is attractive to these buyers because it combines regulation-driven, recurring demand with predominantly public clients. Owners can sell a majority stake and continue to share in further growth, for example through a reinvestment, that is, a stake of their own in the group.
Construction and infrastructure groups. Larger construction companies are acquiring mainly in specialist foundation engineering. They bring methods and capacity in-house instead of buying them in from subcontractors, and strengthen their position for rail and infrastructure projects. MIND's article on engineering firms in infrastructure shows how far consolidation has already progressed in the adjacent field of engineering design.
Which sewer service and rehabilitation companies are particularly attractive from an M&A perspective
Not every company is a target. Buyers examine recurring criteria against which owners can measure their own company.
Recurring revenue. Framework agreements with wastewater utilities, maintenance contracts with industry and the housing sector, and regular inspection cycles make revenue predictable. Buyers look at what share of revenue recurs every year and how long the contracts run.
Equipment and qualifications. A modern fleet, in-house rehabilitation units and robots, an in-house workshop and quality certifications such as the RAL quality mark for sewer construction are prerequisites for many public tenders. In specialist foundation engineering, what counts are specialist methods, equipment utilisation and references with rail and infrastructure operators.
Breadth of services along the value chain. A provider covering inspection, cleaning, repair and renovation can support a network from condition assessment through to rehabilitation. This is exactly the chain buyers are building. A provider that already covers several stages stands out from the mass of add-ons.
Client structure. Public clients stand for stability, but buyers examine a strong concentration on a few wastewater utilities separately. A mix of municipalities, industry and the housing sector spreads the risk.
Second management tier. Site managers, branch managers and estimators who manage clients and projects independently are the key valuation lever.
What this means for owners of sewer service and sewer rehabilitation companies
Consolidation is at an early stage, but it follows a pattern that MIND also observes in adjacent markets such as engineering design and fire protection. For owners, this raises questions that bring clarity even without any intention to sell.
The first is business succession. Where equipment, client relationships and costing depend on the owner, an internal solution is difficult to finance. A sale to a group can close this gap.
The second concerns structure: a full sale or a sale with reinvestment. Those who reinvest share in the group's increase in value. Those who sell completely gain clarity. Both routes are legitimate and suit different stages of life.
The third is the company's own role in the buyer landscape. A larger company with management and systems can itself become a platform, while a smaller specialist fits as an add-on. Valuation and room for manoeuvre after the transaction differ significantly.
The fourth concerns brand and independence. Whether the name, location and management are retained after the transaction is a matter for negotiation and should be clarified early on.
There is no general recommendation to sell. What has changed is the number of options. The need for rehabilitation in the sewer network is structural and underpinned by regulation. Financial investors and construction groups are specifically acquiring providers with their own equipment and recurring revenue. For their owners, this opens up additional options for growth, succession and company sale.
MIND is available at any time for a confidential discussion of strategic options.
