Low groundwater in Belgium: what the 2026 drought means for your installation

The summer of 2026 is ending on a dry note. The late-August showers greened the lawns, but they did not refill the aquifers: in Wallonia as in Flanders, underground reserves remain below seasonal norms, and around twenty Walloon municipalities are still restricting certain uses of water. Here is what that means in practice for a home, a farm or a commercial building — and what is worth doing now, before winter.

On 27 August, the drought expert cell of the Walloon regional crisis centre met to take stock. The assessment published on 1 September is unambiguous: groundwater levels keep falling and are generally below seasonal norms. In limestone and sandstone formations, some are dropping lower than during the dry reference years of 2019 and 2023. Non-navigable watercourses show flows with a return period of five to twenty years — in other words, a situation you do not meet every year.

Twenty Walloon municipalities, among them Bouillon, Rochefort, Theux, Stoumont, Manhay and Chimay, have issued orders limiting certain uses of water. The late-August rain brought relief, not a reversal.

The north of the country is no better off. In early September, more than four in five measuring points in Flanders showed low to very low groundwater for the time of year, and abstraction bans remained in force on almost all non-navigable watercourses.

Two things need to be separated. The production and distribution of drinking water are assured: that is not where the problem lies. What suffers are private resources — wells, boreholes, springs, ponds — and the pumps that go with them.

A well that delivered without faltering for ten years can start drawing air, or bringing up cloudy, iron-laden water, simply because the strainer now sits too close to the bottom. Three signals should alert you: a pump that starts and stops constantly, water turning milky or sandy, and a pressure drop at the furthest taps. A pump running dry, even for a few minutes, deteriorates fast: better to stop it and have it checked than to let it fend for itself.

The Walloon Water Code governs groundwater abstraction. A small domestic well falls under a declaration requirement; agricultural and industrial boreholes require an environmental permit, with flow limits and a meter. We check this systematically before working on an existing installation: a missing declaration is better discovered in September than during an inspection.

The Walloon Region is also preparing a regional restriction plan, which would set a priority order for uses and trigger restrictions once alert thresholds are reached. It is not yet in force — the announced horizon is the summer of 2028 — but the direction is clear: private abstraction will be increasingly regulated. An installation that is in order, metered and maintained is also one that will not have to be shut down in a hurry.

When groundwater falls, every cubic metre that comes neither from the ground nor from the mains is a gain. A properly connected tank feeds the toilets, the washing machine, cleaning and watering without touching drinking water or the well.

It does have to work, though. A clogged filter, an oversized pump cycling constantly, a blocked overflow or a badly set mains changeover, and the tank drains into the ground while you keep consuming town water. Autumn is the right time to put this in order, precisely because it is the season when the tank will fill up.

Read your water meter one evening, then again the next morning without having used anything: any difference points to a leak.

Open the tank cover and check the level, the inlet filter and the pump’s floating strainer.

Clean gutters and downpipes before the autumn rain: this is what decides the quality of the stored water.

Check your municipality’s order before filling a pool or watering heavily.

If your well pump is noisy or cuts in and out, stop it and have it checked rather than letting it run dry.

We work throughout Belgium on these three fronts: checking and recommissioning a well or tank pump, putting a rainwater recovery system in order (filtration, mains changeover, metering), and treating the water when the analysis justifies it. We always start by looking at the installation, and by having the water analysed if needed — not by selling a device.

A dry year is not made up for in one autumn. But a clean, watertight, well-adjusted installation gets through such a period without damage, and that is still what costs the least.