Four water catchment areas in Cuesmes placed under preventi…

The Walloon Public Service published in the Belgian Official Gazette of November 9, 2026, a ministerial decree of October 20, 2026, establishing the close and distant prevention zones for four groundwater intake works for potable water located in Mons, in the village of Cuesmes. The text, referenced C − 2026/008098 and signed by the Minister of the Environment Yves COPPIETERS, enters into force on the day of its publication. It is based on Book II of the Environmental Code constituting the Water Code, and specifically articles R.152 and R.153.

The four affected intakes

The decree specifically targets four water intakes, with their facility code and the cadastral parcels on which they are located, all in division 6 of the municipality of Mons:

La Scierie, facility code 45/27//006, section C, parcels no. 88V, 88W, 88X and 105L2;
Les Grands Prés Marais P2, facility code 45/7/2/004, section B, parcel no. 1588V7;
Les Grands Prés Marais P5, facility code 45/7/2/002, section B, parcel no. 374C;
Les Grands Prés Marais P7, facility code 45/7/2/005, section B, parcels no. 252B, 290M and 290K.

The perimeters of the close zone (zone IIa) and the distant zone (zone IIb) are traced on plans no. 2024.12.16 - CHYDRO-003 - Annexes 4 and 5, available for consultation at the Administration, and reproduced in Annex I of the decree. They are calculated based on the transfer times of a pollutant — 24 hours for zone IIa, 50 days for zone IIb — for operating flow rates of 400, 170, 150 and 205 m³/h depending on the facility, and then adapted to the boundaries of the cadastral parcels.

A nitrate diagnosis imposed on agricultural parcels

The most stringent protection measure is found in Article 3: all agricultural parcels located within the boundaries of the two zones must undergo a complete environmental diagnosis regarding the nitrate pollution observed at the water intake facility. The results will be used to determine the measures necessary to achieve the objective of Article R.168, § 3, paragraph 3, of the Water Code. The maximum deadline is two years and runs from the date the decree enters into force.

Annex III details, for existing installations, a series of deadlines in zone IIa and zone IIb:

Soakaways, including for rainwater drainage: filling within 2 years in zone IIa, 4 years in zone IIb;
Discharges and transfers of wastewater or treated water: 2 years in zone IIa;
Underground hydrocarbon storage from 100 to less than 3,000 liters: leak test by a certified technician within 2 years, immediate replacement if the test reveals a defect;
Above-ground storage: leak test within 4 years, immediate replacement in case of lack of tightness or imminent risk;
Parking areas for more than 5 vehicles: compliance within 2 years;
Existing electrical transformers: 2 years and 8 months;
Signage panels for zone entry and exit: 1 year.

Seventy-eight soakaways and 231 cisterns identified

The environmental declaration annexed to the file quantifies the action program: filling of an extrapolated total of 78 soakaways in zones IIa and IIb, leak tests on 231 fuel oil cisterns, compliance of 3 parking areas for more than 5 vehicles in the immediate zone, 8 electrical transformers, and the installation of 74 signage panels. The maintenance in good condition of fences and gates around the three Marais catchment areas is also planned.

The layouts are based on mathematical modeling conducted with the MODFLOW NWT and MT3DMS codes by the UMONS – Fundamental and Applied Geology Service, following pumping and tracing tests carried out in 2021. Given the context of the former underground quarries of Malogne, the flooded zone of the quarries was assimilated into the La Scierie catchment.

Favorable opinions and public inquiry without observation

The project was submitted to the Environment Hub, the City of Mons, and the SPGE. The SPGE issued a favorable opinion on the action program on March 18, 2024, and then on the environmental impact report and the draft decree on June 23, 2026. The Environment Hub ruled favorably on April 30, 2026, highlighting the text’s contribution to the objective of the Water Framework Directive. The municipal college of Mons closed the public inquiry on May 7, 2026, without any verbal or written observations being formulated. Furthermore, the file overlaps a Natura 2000 zone sheltering bats, birds of prey, and plants.

What changes for residents and owners

For holders of plots or installations located within the perimeters, the decree creates dated obligations, with deadlines running from November 9, 2026: farmers called upon to finance a nitric diagnostic, owners of fuel oil tanks and soakaways ordered to regularize, and concerned managers of parking areas and transformers. The environmental statement recalls that the creation of the zones is judged positive for groundwater, soil, and human health, and that their absence would expose Cuesmes to a risk of flooding in the event of a stoppage of pumping. The detailed plans remain available for consultation at the Administration.

Source: Moniteur belge of November 9, 2026, p. 59793, ministerial decree of October 20, 2026, reference C − 2026/008098, Service public de Wallonie.