Effective flood control and protective measures regarding heavy rain

Today, flood control and protection against impacts of heavy rain are more important than ever. We assist communities in the development of sustainable strategies to identify risks and prevent damage.

Heavy rain threatens entire villages

Statistics show that the number of extreme weather events is increasing worldwide. As consequences of climate change, droughts and floods affect our lives directly. In Germany, extreme rainfall events in particular have led to severe flooding in the recent past. The events of July 2021 showed how quickly rivers can burst their banks and destroy entire communities.

But urban flash floods can also occur far away from streams when sewers are pushed to their limits by heavy rain. The accumulating water masses cannot be drained quickly enough via the existing drainage systems and therefore make their way through the streets. This can lead to considerable damage to persons and property within a short time.

Effective protection against heavy rain is necessary

In order to prevent damage, the implementation of effective measures against heavy rain is required at the municipal level. But where is the best place to start? Which measures have the greatest effect? And what does effective flood protection look like?

The list of possible protective measures against flash floods is long. A holistic approach is essential as preventive measures have to be considered in all urban, transportation and green space planning.

Recommendations for action on flood protection

For this purpose, we generally recommend, wherever possible, near-to-nature management of precipitation water. In the best-case scenario, construction projects are planned in a way that avoids surfaces which generate runoff while at the same time rainwater is used sensibly. In addition, the decentralised retention of rainwater, the creation of evaporation areas as well as local infiltration provide relief for public drainage systems. Furthermore, centralised retention and a delayed discharge of the accumulated precipitation water also constitutes an effective method of flood protection.

Prevention of flash floods: 4 building blocks

There are several ways to identify and protect against risks from heavy rain or flash flooding. The following building blocks form the basis for a holistic solution strategy:

1. Drainage

  • Systematic surface water drainage
  • Emergency drainage, e.g. via streets and walkways
  • Streetscape design that reduces or diverts runoff

2. Area management

  • Creation of retention areas
  • Temporary use of urban (street) spaces as retention areas
  • Multifunctional use of green and open spaces

3. Infiltration/Evaporation

  • Creation of better conditions for the infiltration and evaporation of precipitation water
  • Reduction of runoff-generating surfaces

4. Technical flood protection measures

  • Customised structural protection measures for buildings and residential areas

We are happy to support you in designing your personal protection strategy and are active with our team for private individuals, municipalities and businesses. Do you have questions about our services, or can we assist you in planning protective measures? Please do not hesitate to contact us.

Further information about climate change and its consequences can be found in this Wikipedia article.

Our services “Flood control and protective measures regarding heavy rain”:

Hydraulic hazard analysis

  • Hydrodynamic modelling
  • Collection, incorporation and preparation of basic data
  • Creation of model (direct rainfall, hydronumeric, non-stationary, depth-averaged flow equation)
    – Scenario 1: 30 years, 1h, uncoupled
    – Scenario 2: 100 years, 1h
    – Scenario 3: 90/128mm block rainfall 1h; Baden-Württemberg and North Rhine-Westphalia, respectively
    – Plausibility check of the input data (culverts etc.; source and sink terms, if applicable; simplified urban drainage model)
    – Plausibility check of “neuralgic points” and adjustments of the model
  • Evaluation of simulation results and creation of result plans

Detailed risk analyses

  • Determination of the risk of flooding
  • Analysis of the damage potential
  • Hazard map
  • Prioritisation of measures (in the short, medium, and long term as well as accompanying measures)
  • Superposition of damage potential and risk of flooding
  • Determination of potential monetary damages

Modelling of the runoff with the SCS method

  • Combining the prepared data in one model: subcatchments, soil type and use, sewer data, prepared surface model, rainfall data.
  • Characterisation of runoff behaviour
  • Evaluation after peak discharge

Other services

  • Proof of harmless drainage and discharge according to working papers DWA-A 110 and DWA-M 153
  • Variant comparisons

Expert advice

You can be certain to receive expert advice from us at any time. Our experts in the field of flood control and protective measures regarding heavy rain are at your disposal.

Contact

Contact us! We’ll be happy to help with your questions and queries.