The current or potential danger situation in the commune of Mondorf-les-Bains can be consulted by various means of information:

Flooding

• Flood zone maps
• Water levels, forecasts and early warning

Heavy rains

• Geoportail heavy rain danger map
• Heavy rainfall risk maps for the commune (under development)
• How do you assess a heavy rainfall event ?

In the Geoportail(geoportail.lu), which is accessible to the public, official flood and heavy rainfall hazard maps are freely available for consultation throughout the country. The hazard maps enable everyone to get an idea of the risk situation of their building, and to make a rough assessment of whether and to what extent measures need to be implemented. Detailed questions of personal interest can be discussed with the relevant planners and specialist departments. (link)

Flood and heavy rainfall simulations were also carried out as part of the flood prevention concept. These represent the hazard situation in greater detail than the Geoportal hazard maps.

Official flood zone maps are available in Geoportail under the theme: Water → Flood risk management directive → Flood zone maps 2021.

Three different flood scenarios are available for consultation:

• Low-probability floods (extreme events that occur on statistical average less than once every 1,000 years),
• Medium-probability floods (events that occur on a statistical average every 100 years or less),
• Highly probable floods (events occurring on statistical average approximately every 10 years)

Flood zone maps show flood scenarios for these three zones:

• the extent of surface flooding and
• water depth or, where applicable, water level in the watercourse and in flooded areas

Water levels and forecasts in Luxembourg can be consulted 24 hours a day at https://www.inondations.lu/ (see illustration as an example). Statistical values are
also available for each official level.

Beware !

There are currently no scale measurements on the Gander or on the smaller streams in the Mondorf-les-Bains area (such as the Greimelter- baach). The absence of water level gauges makes it impossible to make forecasts or issue early warnings.

The water authority (AGE) will shortly be installing a water level gauge on the Gander, whose measurements will not appear on the Luxembourg flood forecasting center (on inondations.lu).

As a general rule, warnings are issued on official scales above a certain water level. Alert levels are always linked to emergency plans and behavioral recommendations that citizens must absolutely respect.

Even though there is currently no forecasting and early warning system on the Gander, the recommendations for behavior are general in scope and can be applied to corresponding flood situations in the municipality!

Subtopic: Water → Flood risk management guideline → Intense rainfall, it is possible to display the hazard in the event of heavy rainfall. Unlike floods, only an event of average probability has been considered here, which occurs on statistical average every 100 years or less. (http://g-o.lu/3/4ahD)

The duration of precipitation was set at one hour for the whole of Luxembourg. In Mondorf-les-Bains, rainfall intensity for a 100-year event is between 44 and 55 mm (=l/m²), depending on exposure and altitude.

Water height is not indicated in the heavy rainfall hazard map, but the hazard is represented in classes depending on water height and flow velocity, grouped together in a hazard matrix. Only water depths of > 4 cm are taken into account.

Important note:

The official heavy rainfall risk maps, available on Geoportail, are based on a 2-meter modeling grid, which makes it impossible to deduce reliable water depths.

The atlas of heavy rainfall hazards clearly shows flow paths and, qualitatively, flow depths on a large scale. On a local level, however, the use of 2 m tiles can lead to a specific point not being taken into account, e.g. the location of a critical building or infrastructure is unrealistically scanned, or incorrect water depths are represented.

You will also find suggestions, ideas, behavioural recommendations and additional information in the following sources:
– Ratgeber für Notfallvorsorge und richtiges Handeln in Notsituationen, German Federal Office for Civil Protection and Disaster Relief (BBK) [7], under this link
– Hochwasser-Info for residents of threatened areas of the city of Cologne, Stadtentwässerungsbetriebe Köln (StEB Köln) [8], under this link

Prepare for flooding as much as possible, because in an emergency there are only so many things you can do. Take appropriate personal preventive measures and prepare basic equipment and a first-aid kit, an emergency plan and a checklist that you can use in the short term in anticipation of an event.

This checklist can, for example, include tasks such as setting up movable protective elements, switching off electricity and moving animals or certain objects to safe areas.

It’s very easy to get many of the tools you’ll need in an emergency. Items such as food supplies, a flashlight, spare batteries and an electronic pharmacy are very important for basic personal equipment that will enable you to be self-sufficient for several days in the event of flooding.

Templates for basic equipment, emergency plans and checklists can also be found in the above-mentioned sources. To make the most of your preparation time, keep up to date with the latest weather forecasts!

Make sure that people who are ill or in need of care are accommodated by relatives or friends. If this is not possible, organize help through private services or aid organizations. In this way, medical care and assistance can be maintained.

Find out how to behave by consulting the above-mentioned sources, in particular the association’s website, especially in the event of flooding in your own building. Don’t forget that rescue organizations can’t come for trifles. In the event of a serious health hazard, call 112.

Remove containers of used oil, chemicals, paints, varnishes, detergents and cleaning products from rooms deep below the surface, as they not only affect the water and your premises, but also extend to the surrounding area as a result of flooding. If, despite all safety precautions, environmentally hazardous substances escape, notify the fire department immediately. Any delay exacerbates the damage.

Keep in mind that cellars, garages and sunken rooms can be flooded in the event of high water. If water is at the door, a stay in the basement can even be fatal.

Take notes and document the event ! Note current water levels and draw up a table of critical water levels and reference points :

What is the situation at certain water levels in your immediate vicinity ?
At what water level does the water reach your home ?
When is the heating system / … affected?

What’s left to do ?

• Turn off the main gas, water, electricity, heating and oil taps;
• Provide emergency lighting. Your electricity supplier can tell you if and when the power will be cut off in your neighborhood ;
• Pumping water: fire departments do not usually make pumps available during the flood phase. Pumping water into deep rooms is also not without danger during a flood. Emptied rooms can collapse under the immense pressure of external water. In some cases, the stability of your building may be at risk.
• Help your neighbors too !

Please remove mud from your building as quickly as possible, before it dries and becomes more difficult to remove.

Once the sludge has been removed from the buildings concerned, it’s time to start drying out the building as quickly as possible. As a safety precaution, you should first check whether there is a risk of electric shock, and whether any chemicals or fuel oil have been spilled. Food that has been in contact with water should be discarded. Please document all damage with photos and inform your insurance company.