In the UK you can use a Govt website to check firstly if you are at risk generally from flooding from rivers or the sea or surface water.
To check if you are at imminent danger of flood risk, or within the next 5days, or predicted river/ sea/ groundwater and rainfall levels there is a different link to use:
In the USA you can check FEMA /FIRM (Flood Insurance Rate Maps) floodmaps for your area on the FEMA website.
If you need more detailed information then you will need to undertake a Flood Risk Assessment of your site. As well as giving details of the likelihood and severity of any likely flooding these can also suggest ways to manage / minimise your risk.
There are many types of flood defence from temporary barriers that are taken to a site in advance of a flood and manually erected, to permanent walls of concrete or glass floodwalls, to fully automatic flood barriers that deploy without human intervention. The costs need to balance against the risk of losses, and the expected amount of warning and personnel availability to protect your site before a flood.
Extreme rainfall events are increasing and river levels are likely to rise in the future during these events. To protect a site against river flooding this would normally mean building a bank or a wall to keep the river in its channel. Where this is visually unacceptable then glass floodwalls are a good flood defence solution, as they keep a ‘connection’ to the river in normal times, and can protect without human intervention should river levels rise. If there is a bank or wall with access points through it, these can be protected with demountable flood barriers or floodgates that are shut in advance of the flood.
There are many factors that are used to determine the best flood protection solution for a site. Cost / warning time and manpower availability / aesthetics / allowable leakage rates / geometry/ space limitations of your site / frequency of operation. The ration of importance of all of these is different for every site, and so there is not one ‘best’ type of solution. FCI work hard with clients to determine what is best for each and every project.
There are several standards across the world that will give ‘allowable leakage rates’ for all types of flood barrier. Generally there is a differentiation between ‘temporary barriers’ which are not location specific and are asked to work on a variety of ground surfaces. These often have a leakage rate of 300 litres/metre/hr (24 gals/ft/hr), and will often need pumps behind them to throw the water back over the barrier.
Next there are ‘perimeter floodgates or barriers’ which are generally around the outside of a building. You can imagine it will be raining on both sides of these barriers during a flood event and so a mid-way leakage rate is allowed for of 40 litres/ metre/hr (3 gals/ft/hr).
Finally, for flood doors that may be keeping ‘the carpet dry’ there is the tightest leakage rate of 1 litre/metre/hr (0.08gals/ft/hr).
Ultimately each client will have different requirements, and the correct allowable rate can be calculated with site specific parameters.
