It is widely acknowledged that flooding are now responsible for many deaths every year and cause significant damages.
In order to protect your property, yourself and your family make sure you are prepared for future floods. This site will give you guidance in relevant aspects of flood preparedness.
It is common that residents are unaware of flood risks and/or believe that public flood defence measures are sufficient to protect them in case of flooding. In addition to the existing flood risks, residents are often not properly informed about immediate danger due to heavy rainfall or floods occurring in their area. The latter is particular the case if a flood wave arrives from upstream areas, without actually experienced significant rainfall at their place of residence. The lack in information precaution results in increased flood risk, as often neither residents are prepared for a flood event in terms of floodproofing the building, adaptation of building utilisations or insurance coverage, nor adjust their behaviour towards the imminent danger of an occurring flood.
There are sources of information residents should seek for their own precaution. However, the availability of such information depends on the country or regions residents are located. Therefore, residents are advised to ask their local authority for available information. Common sources of information are shown below and put into a temporal perspective, i.e. before-, during- and after a flood.
Here are useful information’s about weather warning forecast, flood maps and how to learn more about flood hazard and risk.
Weather Forecasts and Warnings | World Meteorological Organization (wmo.int)
World Resources Institute at the Global Flood Analyzer
Water Risk Atlas
In many cases countries' responsible ministries do provide comprehensive information’s as well.
Check the e-learning course about Flood Risk Management for free. Understand the fundamentals of flood risk management and forecasting and learn how to implement ideas and measures to prevent damage: https://www.edx.org/course/flood-risk-management
If your house is subject to flood hazards, it is recommended to floodproof your house in preparation of future floods. Floodproofing can be achieved through methods which minimizes the damage of future floods, either through remodelling of existing buildings or adapted construction of new buildings.
Generally, flood damages occur when water is able to enters the house/building. There are common routes of water into a building, which are shown in the below figure, and linked to their specific flood hazard type. As a general rule, floodwater first enters the building through low-lying openings, such as basement windows and doors, shafts and light wells, as well as through doors and window at ground floor if water levels are high enough. Even if openings are not present, seepage through the walls, cannot be ruled out, depending on the building- and material quality and length of flooding.
Furthermore, walls are used to feed pipes from the outside into the house (e.g. electricity, gas, telephone, drinking water, sewage). Since water will always find the weakest link into the house water will drain into the house via cable ducts if not properly waterproofed or sealed off.
Furthermore, water can enter the building through the roof during heavy rainfall or sanitary utilities during sewer backflow.
Moreover, damage can also occur from to the house/building due to load conditions from the outside to the house/building, such as hydrostatic water pressure and buoyancy, hydraulic fracture and subsoil erosion (undercutting of the building), as well as impact pressure from water velocity and flotsam (e.g. debris flow).
The task of floodproofing is to limit the damage potential to the property. This can either be done by protecting the house/building from water affecting the building either from the outside, from entering the building through intrusion routes or adapting the building to flood water.
For floodproofing new constructions or retrofitting of buildings/houses the use of flood-damage-resistant materials should be considered. In the following download document a material guide is provided in table form with building materials linked to their ability to resist floods.
Floods can affect everyone, in the form of river floods and heavy rainfall, but also through sewer backflow and coastal flooding. It is therefore important to learn the right behaviour in an emergency situation in advance of the event. Behavioural preparedness is an important part of flood prevention, as appropriate preparation can significantly reduce damage. Knowledge of the specific hazard is the basis for an appropriate response to the hazard. In addition to protective measures, this also includes behavioural precautions, such as preparing an emergency response plan and an emergency bag.
Preparing an emergency response plan will help thinking through all the details that will demand attention as the floodwaters approach. Before, during and after the event there are many tasks to be done which demands coordination in a hectic and agitated situation which is difficult to pursue without a plan. This is a project for the whole family. The family should write down a plan together so that everyone understands it. And having the plan written helps people remember what to do when everyone is in a hurry and nervous due to an approaching flood.
The emergency response plan depends on the type of flood hazard, status of technical flood protection, available local warning procedures and the estimated warning time. The response time may be a couple of hours or even days for larger rivers and less than an hour for smaller rivers. In the latter case people might only have enough time to evacuate the house. In some extreme cases of flash floods, no warning time is available at all.
Depending on the local characteristics, the triggers should be considered setting up emergency response plan.
The emergency bag shows examples of items that should be on hand in the event of a flood or other emergency, such as important documents, food, water and emergency communication equipment. The bag can be grabbed and the building evacuated immediately because all the necessary items have been safely packed in advance.
In this way, the emergency bag not only provides assistance immediately after the event, but also creates a calmer evacuation situation at the moment of entry.
