Underground tank leak detection for apartments in Al Mrwj, Riyadh

Prepared by the technical team · editorial review · last updated 13 November 2026 · Sources

Before we start: what we know about Al Mrwj

The centre of Al Mrwj is at 24.7578, 46.6637, about 5 km from the centre of Riyadh, with an approximate radius of 2.1 km. The approximate area shown on the map is centred here. Al Mrwj has both villas and apartment buildings.

The centre of Al Mrwj sits about 635 m above sea level (SRTM open elevation data). Main roads in or near Al Mrwj: King Fahd Road, Northern Ring Road, King Abdulaziz Road.

The nearest wadi channel is about 2.8 km from the centre of Al Mrwj (OpenStreetMap).

Picture the owner of an apartment building in Al Mrwj who has noticed that the water bills have crept up while the building's pump seems to run more often than it should. Nobody in the building has seen a wet patch, yet the owner suspects that something below ground is losing water. Owners of this kind of property often wait a long time before checking, because the tank is out of sight and the symptoms are easy to blame on heavy use or a faulty meter.

The local facts help explain why checking is worthwhile. Al Mrwj has both villas and apartment buildings, so many shared tanks serve several households at once, and a leak that goes unnoticed affects everyone who depends on that supply. The centre of the district sits at 24.7578, 46.6637, about 5 km from the centre of Riyadh, within an approximate radius of 2.1 km, which means that most buildings here are close enough to the city's mains and pumping network that a steady loss is easy to compare against normal consumption. The centre of Al Mrwj sits about 635 m above sea level (SRTM open elevation data), so pressure at the tank and at upper floors should be checked against the building's own baseline rather than assumed. The nearest wadi channel is about 2.8 km from the centre of Al Mrwj (OpenStreetMap), so the ground in the wider area can shift with runoff, which is a reason to inspect tank walls and joints rather than rely on a single reading.

A sensible sequence starts with records. Gather the last several months of water bills and note the pump's running hours if they are logged. Next, take the water level in the tank, stop all taps and appliances for a set period, and measure again to see whether the level falls on its own. If it does, inspect the tank walls, the inlet and outlet pipework and the valves for damp or staining. Where the tank needs repair, price the internal coating, which is SAR 25–70 per m², and ask for the area to be measured before any work is quoted. Finish by agreeing the repair schedule with all households, so that the building is not left without water during the works.

In an apartment, a problem may start in your unit or in a shared line; we separate the two before any work.

Signs worth paying attention to

These are the signs most often linked to underground tank leak detection:

• The tank needs refilling faster than usual
• Damp or salt marks on the tiles above the tank
• A noticeable drop in the water level overnight
• The pump runs for longer periods

Where the problem usually comes from

• Construction joints and corners.
• Cracks in the concrete tank walls or floor.
• A float valve that does not close, so water is wasted.

Tools and methods, and when we use them

How the work is done, step by step

1. Safety first: Tank lids and confined spaces are handled with ventilation and a second person on site.
2. Documented level test: Filling and use are stopped and the level is recorded against time.
3. Isolating the tank from the network: This tells us whether the loss is from the tank body or from the supply line.
4. Checking the body and connections: Inlet, outlet and overflow connections are inspected.
5. Recommendation: You get the next step in writing: repair, waterproofing or a line test.

Quick comparison: facts and costs in Al Mrwj

Common questions about underground tank leak detection in Al Mrwj

Common mistakes we see

• Waterproofing the tank before confirming the loss is from the tank and not the line
• Ignoring the float valve

The written outputs

You receive: the written level-test result and the recommended next step, in a technical report with a verification code.