How to effectively secure home against flooding? Practical advice and protection methods
The climate change we are currently experiencing has amplified extreme weather events. A storm in February? Heat waves in March? Floods and localised flooding from spring to autumn? Slowly, they become no longer surprising. Unfortunately. As it turns out, none of the inhabitants of our planet can be sure that they, too, will not be affected by the destructive power of nature. How to protect our possessions from flooding? We suggest the steps to take to secure your home against flooding.
In this article, you will learn how:
- carry out a flooding risk analysis;
- protect the house and garage from flooding and inundation during renovation works;
- protect the property from actual flooding during floods.
Which areas of Poland are most frequently at risk from flooding and inundation?
Poland is a country relatively often hit by floods and localised inundation. According to various data, hundreds of such events occur every year. The areas most prone to flooding are located along the big rivers, namely Vistula, Oder, Warta and Narew. Localised inundation is an even more common phenomenon. It occurs in low-lying areas, often as a result of heavy rainfall or snowmelt.
According to the 2012 data from the Provincial Disaster Management Centres, the land and infrastructure in 1,039 municipalities are at risk in Poland, including i.e. over 875,000 hectares of agricultural land, 86,500 residential buildings, 2,600 public buildings, approximately 2,000 bridges and over 280 sewage treatment plants.
The most common floods are floods caused by rainfall. The areas most exposed to the risk of flood occurrence are the Lesser Poland, Sub-Carpathia, Silesia, Opole and Lower Silesia provinces. In contrast, 839 rivers with a total length of 27,161 km were classified as areas at risk of flooding. In the case of urban flooding, the most exposed cities are Warsaw, Łódź and Poznań.
The frequency of floods and inundation has been increasing even faster in recent years. Why? This is caused by climate change, which is leading to more frequent and more intense rainfall.
In Poland, many areas are called floodplains, which indicates a higher risk of flooding. Following the devastating floods of recent years, legal changes precluding the construction of houses in flood-prone areas have been introduced since 2018. Before buying a plot of land for your dream home, always check if it is located in such an area. What to do if you already own a property in a flood-prone area?
How to assess the risk of flooding where you live?
In order to prepare yourself and your family well, but also to protect all your possessions against possible flooding, you should assess the likelihood of flooding is and what its potential consequences could be.
Detailed information on floodplains can be found on the websites of the Polish Water Authority and the municipal authorities. Experts divide floodplains into four zones, depending on the likelihood of flooding:
- Total flooding zone (after a levee break)
- Zone with flooding probability every 10 years (10%)
- Zone with flooding probability every 100 years (0.1%)
- Zone with flooding probability every 500 years (0.02%)
Particularly vulnerable are the following areas:
- areas between the shoreline and the levee;
- land plots near rivers and lakes with high water levels;
- islands, alluvia and technical land strips.
Floodplain information can also be found in the Local Development Plan (LDP) – which is available at www.geoportal.gov.pl – and on the flood risk maps which are available on the ISOK Hydroportal website (https://isok.gov.pl/hydroportal.html).
Experts estimate that approximately 7 million people live in flood risk areas in Poland. We should remember, however, that such estimations are quite general.
Thanks to the information on the type and frequency of floods in your area, you can take the necessary steps to protection your home against flooding. You should also remember that floods can occur suddenly and with little warning, which is why it is so important to be prepared for every possibility.
Flood risk map for Europe: https://discomap.eea.europa.eu/floodsviewer/?page=Page
How to carry out a home flooding risk analysis?
Although this is a rather arduous task, it is necessary in order to properly assess the hazard and its severity. If you want to find out if you are at risk of flooding, you need to check the location of the nearby rivers, the direction of their flow and how often and to what extent they have flooded the local area in the past.
Next, assess the location of your home in relation to the potential flood zones and the structural condition of the building and the quality of its foundations. Consider whether the building has adequate waterproofing and offers flood resistance, but also what the potential consequences of flooding might be and how you can already protect yourself against them.
Preparing your home for flooding – how to secure your building?
The risk of flooding and localised inundation caused by the progressing climate change is increasing every year. No one can actually be sure whether they will experience such a cataclysm in the future. The saying that prudent people are always insured has been used for a while for a reason, after all. However, if you live in an area at particular risk of flooding, you should take steps to prepare your home for flood in advance. What can be done to minimise the risk of damage and material losses?
Protecting the house foundations against contact with water – foundation waterproofing
Solid foundation is also a solid basis of protection, first and foremost. Take care of foundations waterproofing, which will adequately protect the foundations against contact with water. Waterproofing foundations – how to do it? An applied layer of horizontal and vertical insulation is helpful here. Horizontal insulation is applied on the foundations and protects the foundations from groundwater. Vertical insulation, on the other hand, is used to protect the foundation walls against damp.
Materials with high water resistance, such as waterproof concrete or stone, will also adequately protect the foundations. But that is not all, the use of drainage is also helpful to allow water to be drained away from the area around the foundations. Installation of damp-proof membranes is also a good method protecting the foundations from water infiltration.
Waterproofing basement windows
If your house has a basement and windows in it, such windows also need to be adequately protected against flooding. It is a good idea to install windows with improved water resistance, such as PVC windows with seals, already at the house building or renovation stage.
Flood guards protecting windows against water penetration inside can also be helpful. Once the windows are secured, it is recommended to provide drainage ditches around the windows, similar to the basement, enabling water drainage.
Raising the house entrance
Water enters the house not only by seeping through the foundations, but also through doors and windows. Securing these elements properly will help minimise the adverse consequences of flooding. Experts recommend raising the house entrance, which can largely stop the water.
This includes raising the level of the house entrance and building an entrance staircase. Next, anti-flood thresholds protecting the doors against water should be used. It is also a good idea to replace the doors and use sealed doors, improving water resistance.
Protecting the drains from flooding – how to do it?
While securing windows and doors seems obvious, securing drains against flooding is not necessarily so. Install anti-flood valves to prevent the return flow of water from the drains into the house. Also install a water pump to quickly remove excess water from drains in the event of a flood emergency.
Securing the garage and farm buildings against flooding
Securing the house is not everything. What remains is the garage, the other farm and utility buildings and the area around the house. In the case of a garage, it is also necessary to waterproof the foundations to protect the structure from water penetration. It is also useful to install flood guards on the doors and windows to protect the interior from flooding and to install drainage allowing water to drain away from the area around the buildings.
The next step is to ensure that the area around the house is protected. How can this be done effectively?
Raising the ground level at the plot
Firstly, it is recommended to raise the ground level of the plot to one minimising the risk of flooding. Extra soil, sand or gravel should be prepared and used in order to raise the plot to a suitable level. The material then should be spread evenly over the plot area, resulting in the desired ground level. Remember to shape the material such that it ensures effective drainage of rainwater.
This can be facilitated by preparing appropriate ground inclinations or creating drainage ditches redirecting rainfall water away from the buildings. Plants planted in the ground also have a positive effect, as they absorb excess water and prevent it from accumulating at the plot. To effectively protect the land plot from flooding, it is also worth installing flood defences, such as sandbags or water barriers at the plot.
Flood defences – what are the available options?
We have mentioned the use of flood defences before, now it is time to take a closer look at those. Flood defences are various solutions designed to protect the home and the land from flooding. They include fixed flood barriers and mobile flood protection systems.
Although there are many types of flood barriers available, the most popular ones include mobile barriers made of aluminium, plastic or wood, which can be easily set up and taken down, as well as permanent barriers, which are usually made of concrete, steel or stone. These are more robust than mobile barriers, but are more costly to build.
Mobile flood protection systems – how do they work?
If you do not want to install a permanent barrier, you can always opt for mobile flood protection systems. These are state-of-the-art solutions providing quick and effective protection of your home from flooding. Their use includes the temporary installation of flood defences, which can be easily removed once the danger has passed. Mobile flood barriers are:
- easy to assemble and dismantle, allowing a rapid response to flood risks;
- versatile, which means they can be used in a variety of locations, such as house and garage entrances and drains;
- very effective protection against flooding, thanks to the use of water-resistant materials.
An example of such a mobile barrier, which provides an effective alternative to sandbags, is the flexible Exflooder flood barrier. It is made of three-layer PVC fabric ensuring durability and resistance to micro-damage. It adapts to terrain unevenness to provide tight protection.
It is also easy to install, even by persons without experience, as it requires no additional structure or supports. Simply unfold it and fill it with water, and when the danger has passed, empty it, fold it back and store.
What makes the Exflooder flood barrier effective in all conditions?
Prototypes of our mobile flood barriers were tested by teams of experienced fire-fighters under real conditions (see article). In Gdynia, their effectiveness was tested during a backwater on the quay, accompanied by strong winds and rising rainwater levels. In Opole, it was tested during rising water levels in the river. In Podłopień, on the other hand, the barrier provided protection against water from mountain streams and rivers coming down at the surrounding houses.
While tests have shown that there is no perfect barrier providing effective protection against every type of flood and adaptable to every terrain, we set ourselves an objective to create a universal barrier which combines all the requirements related to the different types of flooding.
As a result, we have created a barrier which:
- has greater resistance to damage and a longer service life, thanks to a more resilient fabric with a better quality coating,
- offers a more robust connection and improved ventilation, making filling faster,
- offers anti-roll and anti-slip protection,
- empties faster and allows inspection,
- enables fast serial connection to other barriers,
- once filled, it is taller than competitive barriers.
Once you have selected the right type of a flood barrier, taking into account its height and length, you can install it yourself. However, in order for the barrier to do its job properly, its installation location must be chosen properly – it must be stable and level.
What to do when flood is inevitable?
Despite taking every precaution, sometimes a flood is inevitable. What action can be taken to minimise the damage caused by flooding? First and foremost, prepare an evacuation plan outlining what to do in the event of a flood risk. Also prepare an emergency kit containing the items required to survive for the first 72 hours after a disaster. Such a kit should include drinking water, food, a first aid kit as well as personal documents or clothing.
When flooding and inundation of your home is only a matter of time, it is worth taking the final steps to protect your possessions against water. Move valuables, documents and electronic equipment to higher floors of the house or elevated places to protect such items against flooding. Disconnect electricity, gas and water supply to avoid possible breakdowns and damage to the installations. Secure windows and doors with special flood shields or sandbags to limit the amount of water entering your home. Make sure that any vents and drains are sealed to avoid water flowing back into the house. Where possible, move your car and other vehicles to higher ground to protect them from flooding.
A water pump will also help to protect your home against flooding. Choose a water pump by considering its capacity, power supply and the type of water it will work with (clean, dirty, contaminated).
Home insurance as a form of protection against the risk of flooding
If flood poses a real threat to your possessions, it is worth considering home insurance as an additional form of protection against the risk of flooding. Insurance can cover the cost of home repairs or rebuilding and compensate for losses caused from flooding.
It is worth taking the time to compare insurance quotes, as they may vary considerably and not just in price. Good flood insurance should provide comprehensive protection against various types of flooding – whether caused by a flood wave or flooding caused by a waterworks or sewerage system failure. The insurance cover should include not only the building, but also the furnishings, auxiliary buildings and the possible rent costs of temporary accommodation if the flooded property has to be vacated.
Conclusions
Although unexpected disasters and extreme weather events will accompany us ever more frequently, we can ensure effective protection against at least some of them. With knowledge of the area where you live and by monitoring the hydrological situation, you can prepare your home and land against possible flooding and inundation accordingly.
Fortunately, there are already many ways to effectively protect your home against flooding – from foundations, through windows and walls, to using modern flood defences and choosing the right insurance. However, it is important not to leave everything to the last minute, to check the current condition of your defences and to monitor messages so that a possible flood does not come as a surprise.