Flood control walls, dikes or dams serve to protect and reduce the damage. But especially with the rising intensity of weather phenomena, the potential hazard remains a realistic threat, as dikes can break, flood walls can be deluged and dams overflown. In all of your proactive measures it is fundamentally important, that you do detect the weak spots at your site in order to undertake very targeted the appropriate additional precautions for your property`s flood protection.
Where watercourses do pass narrow stretches and also at bridges and culverts - those are the spots prone to be blocked by flotsam, so that hardly any water can flow through the usual passages. The formation of those so called debris jams are a common threat in the course of floods. Exactly then when larger amounts of water with high flow velocity carry away a particularly high amount of flotsam. Often causing devastating damage through flood extend and expansive aggradation above those bottleneck spots of debris jam.
Therefore, pay attention to bridges or culverts at the waterways in your neighborhood. The potential flooding areas shown in the maps can quickly grow to much larger extent in the wake of debris jam and it’s causes. This risk of many loose materials accumulating in the course of a flood to a big mass causing big mess you can also contribute to diminish by taking care in your own backyard: Make sure that you do not store potential material for debris jams, such as all kinds of kitchen and garden waste, residual disposal or bulky- and construction waste.
What do you know about the foundation`s conditions of your house?
The stability of buildings in the immediate vicinity of a river or brook may be at risk in the event of incorrect construction. In unfavorable cases, the foundations of the building can be washed out. And the longer the flood lasts, the more the soil is removed under the foundation. The resulting lacks of earth foundations can even lead to the building’s subsidence.
An underestimated threat of damage to buildings is flotsam. From it’s harms not only the building side facing the water must be affected, the building’s side walls can suffer from scratches and impacts caused by flotsam.
Where watercourses do pass narrow stretches and also at bridges and culverts - those are the spots prone to be blocked by flotsam, so that hardly any water can flow through the usual passages. The formation of those so called debris jams are a common threat in the course of floods. Exactly then when larger amounts of water with high flow velocity carry away a particularly high amount of flotsam. Often causing devastating damage through flood extend and expansive aggradation above those bottleneck spots of debris jam.
Therefore, pay attention to bridges or culverts at the waterways in your neighborhood. The potential flooding areas shown in the maps can quickly grow to much larger extent in the wake of debris jam and it’s causes. This risk of many loose materials accumulating in the course of a flood to a big mass causing big mess you can also contribute to diminish by taking care in your own backyard: Make sure that you do not store potential material for debris jams, such as all kinds of kitchen and garden waste, residual disposal or bulky- and construction waste.
A scenario that you certainly know, and actually is easily to prevent: Heavy rains very quickly tend to overflow roofs and rain gutters.
If the spilling waters then spread on sealed grounds, such as paved terraces or garage driveways, where they - also due to their sheer amount - cannot seep through the ground, those waters then do jam up and can run into the entrances and other low positioned openings of the building. Another source of significant destruction.
Is your building situated in a hollow? Then you have to protect it from the risk that rainwater collects in the lowest points of hollow, which happens if it cannot seep or drain quickly enough. This is particularly the case for asphalt or paved terrain or also if there is a lack of gradient. As well this concerns frosted and icy grounds, and water-saturated soils, because they can no longer absorb water.
On a location like that even a sewer - if there is one at all - often proves to be insufficient by it’s drainage capacity.
In the event of heavy rainfalls and other flood incidents the water quickly gathers in this very depression. If exactly there the house is situated it will formally sink into a lake. Hence here the water is literally invited to penetrate through all the building’s openings: beginning in the lowest areas, such as via light shafts, basement windows and ground doors… bringing danger and damage.
Built too close to the hillside? If the slope is sealed by pavement, cobbles etc., or if the soils are icy or already soaked, in the course of rainfall there is a high risk for strong draining from the hillside, in the worst case directly running into the building. The situation is comparable to a building located in a depression, but with only one-sided water inflow to the building.
A further danger may arise with long-lasting rainfall: If the slope is not covered with plants, or only with plants that have no deep roots, then the upper hands widths of this slopes` unprotected soil will get completely soaked. Very probably this condition will lead to one and more landslides, running off the hill to the below-lying building and penetrating it through it`s openings.
Is your house located in a potential flow path of a raging torrent, caused by heavy rain? Not only river beds but also urban streets, or bigger and smaller canyons are perfect path ways where they can rip through, sweeping everything before them.
Flash floods occur in the course of heavy rainfalls - within very short time. Mostly vulnerable are sealed surfaces, and also soaked or icy soils. The water masses run-off the gradients and accumulate in dips on roads and trails, where they can accumulate incredibly fast into raging torrents. If a building is located on the flow path such a torrent is ripping through, water can penetrate into the building, especially through unfavorably positioned windows and doors. Be aware, that there is increased danger due to the high flood speed of those torrents.
After heavy rainfall or during a flood this scenario ist often the case:
Wastewater from a building no longer drains away properly. Instead it collects, for example, in the basement and can cause considerable damage.
How on - and in earth can this happen?
Heavy rain or flooding can lead to a back up in the public channel. The entire rain water can no longer run off. As a result, water from the public canal system pushes into the private property pipes. Thus sewage from the houses can no longer flow into the canal. On the contrary: In the basement as well as the lower floors, this back pressured wastewater will spill from toilets, sinks, floor drains etc. throughout the spaces.
Already the imagination of this is more than unpleasant. You can increase your chances to be never be affected significantly by appropriate and simple measures. For example back-up valves or sewage lifting systems, which have to be installed depending on the building`s situation.
When connecting rain gutters to the wastewater system, take care to have behind the flap a built-in non-return valve.
In the case of a wrong installation, the rain water will enter the building.
There are many ways water can enter a building. Here are some examples:
