Water collection, treatment and supply: the largest companies in Wallonia
As of 14 Nov 2026, 19 companies in Water collection, treatment and supply (NACE 36) in Wallonia publish total assets in recent accounts (financial years 2024 to 2025). The top 10 account for €3.47bn, out of €3.48bn for all of them; median total assets are €1.50m. Societe Wallonne des Eaux leads with €2.56bn (financial year 2025).
Top 19 · Water collection, treatment and supply · Wallonia
Ranked by total assets in the latest filed accounts. This is a size criterion, not an assessment.
Ranking based on each company's own annual accounts (statutory, not consolidated): a subsidiary and its parent appear separately, and the ranking differs from lists based on consolidated group accounts.
“—”: not published. Small companies (micro and abridged accounts) do not have to publish their revenue.
Water collection, treatment and supply across Belgium → All sectors · Wallonia →
Other sectors · Wallonia
- 01 Crop and animal production, hunting and related service activities2,551
- 02 Forestry and logging541
- 03 Fishing and aquaculture31
- 08 Other mining and quarrying121
- 09 Mining support service activities17
- 10 Manufacture of food products1,478
- 11 Manufacture of beverages275
- 13 Manufacture of textiles155
- 14 Manufacture of wearing apparel101
- 15 Manufacture of leather and related products of other materials18
- 16 Manufacture of wood and of products of wood and cork, except furniture; manufacture of articles of straw and plaiting materials442
- 17 Manufacture of paper and paper products57
- 18 Printing and reproduction of recorded media532
- 20 Manufacture of chemicals and chemical products239
- 21 Manufacture of basic pharmaceutical products and pharmaceutical preparations179
- 22 Manufacture of rubber and plastic products196
- 23 Manufacture of other non-metallic mineral products441
- 24 Manufacture of basic metals140
- 25 Manufacture of fabricated metal products, except machinery and equipment1,528
- 26 Manufacture of computer, electronic and optical products210
- 27 Manufacture of electrical equipment185
- 28 Manufacture of machinery and equipment n.e.c.379
- 29 Manufacture of motor vehicles, trailers and semi-trailers114
- 30 Manufacture of other transport equipment56
- 31 Manufacture of furniture278
- 32 Other manufacturing409
- 33 Repair, maintenance and installation of machinery and equipment654
- 35 Electricity, gas, steam and air conditioning supply276
- 37 Sewerage67
- 38 Waste collection, recovery and disposal activities297
- 39 Remediation activities and other waste management service activities29
- 41 Construction of residential and non-residential buildings4,193
- 42 Civil engineering477
- 43 Specialised construction activities12,039
- 46 Wholesale trade8,104
- 47 Retail trade12,950
- 49 Land transport and transport via pipelines1,819
- 50 Water transport41
- 51 Air transport53
- 52 Warehousing, storage and support activities for transportation567
- 53 Postal and courier activities126
- 55 Accommodation1,322
- 56 Food and beverage service activities6,704
- 58 Publishing activities410
- 59 Motion picture, video and television programme production, sound recording and music publishing activities595
- 60 Programming, broadcasting, news agency and other content distribution activities69
- 61 Telecommunication130
- 62 Computer programming, consultancy and related activities5,398
- 63 Computing infrastructure, data processing, hosting and other information service activities468
- 64 Financial service activities, except insurance and pension funding3,810
- 65 Insurance, reinsurance and pension funding, except compulsory social security111
- 66 Activities auxiliary to financial services and insurance activities2,334
- 68 Real estate activities12,723
- 69 Legal and accounting activities5,344
- 70 Activities of head offices and management consultancy12,300
- 71 Architectural and engineering activities; technical testing and analysis3,981
- 72 Scientific research and development396
- 73 Activities of advertising, market research and public relations2,471
- 74 Other professional, scientific and technical activities1,209
- 75 Veterinary activities727
- 77 Rental and leasing activities793
- 78 Employment activities299
- 79 Travel agency, tour operator and other reservation service and related activities262
- 80 Investigation and security activities133
- 81 Services to buildings and landscape activities1,907
- 82 Office administrative, office support and other business support activities2,358
- 84 Public administration and defence; compulsory social security39
- 85 Education1,500
- 86 Human health activities14,912
- 87 Residential care activities736
- 88 Social work activities without accommodation561
- 90 Arts creation and performing arts activities659
- 91 Libraries, archives, museums and other cultural activities86
- 92 Gambling and betting activities46
- 93 Sports activities and amusement and recreation activities1,303
- 94 Activities of membership organisations326
- 95 Repair and maintenance of computers, personal and household goods, and motor vehicles and motorcycles1,290
- 96 Personal service activities1,967
Municipalities with the most companies in the sector · Wallonia
- 4140 Sprimont (Dolembreux, Gomzé-Andoumont, Rouvreux)2
- 4800 Verviers (Ensival, Lambermont, Petit-Rechain, …)2
- 7700 Mouscron (Luingne)2
- 1402 Nivelles (Thines)1
- 1480 Tubize (Clabecq, Oisquercq, Saintes)1
- 4031 Liège (Angleur)1
- 4190 Ferrières (My, Vieuxville, Werbomont, …)1
- 4550 Nandrin (Saint-Séverin, Villers-Le-Temple, Yernée-Fraineux)1
- 4560 Clavier (Bois-Et-Borsu, Les Avins, Ocquier, …)1
- 4850 Plombières (Montzen, Moresnet)1
- 5100 Namur (Dave, Jambes, Naninne, …)1
- 5361 Hamois (Mohiville, Scy)1
Frequently asked questions
Which is the largest company in Water collection, treatment and supply in Wallonia?
By total assets, it is Societe Wallonne des Eaux (€2.56bn, financial year 2025).
How many companies in Water collection, treatment and supply in Wallonia are ranked?
19 out of 20 active companies in the sector with their registered office in the area: those whose latest accounts are less than 3 years old.
Why does this ranking differ from other lists?
It uses each company's annual accounts as filed with the National Bank, not consolidated group accounts. A holding, a subsidiary or a purchasing entity can therefore appear separately. Only companies whose latest accounts are less than 3 years old are ranked.
Analyse companies · Wallonia
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Open the full file →Active companies (legal entities) that have filed at least one set of annual accounts, based on the Crossroads Bank for Enterprises and the National Bank of Belgium. The sector is the main activity in the register; the municipality is that of the registered office. Data updated on 14 Nov 2026.