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The Overtopping Manual

This page contains some additions and discussions related to the overtopping manual. 

For further information is referred to:

A pdf with errata (on the first internet edition)

The Neural Network as can be downloaded from does not work properly because of missing licence file. See updated information below.


Section 5.3.1, p82, equation 5.11:
Lander Victor remarks that the definition of the power c in the formula is not clear. In probabilistic calculations c can be considered as a stochast with mean -0.92 and a standard deviation of 0.24.
For deterministic calculations an exceedance frequency of 15% is assumed. The Gaussian distribution gives u15% = 1,035. So c becomes c=-0.92 + 1.035*0.24 = -0.672.  And 10-0.672 = 0.21. This is the coefficient in equation 5.10.

Section 5.4, p 99, equation 5.33:
Lander Victor remarks that Tm in eq. 5.33 might be replaced by Tm-1,0, which is in line with figure 5.32, also mentioning Tm-1,0.

Section 6.3.3, p118, equation 6.8
Corrado Altomare remarks that the formula presented here is different from the formula originally presented by Van der Meer, and in the Manual presented as formula 5.24. In that formula a multiplier (1-0.0033β) is used, while in 6.8 a multiplier (1-0.0063β) is used.
Formula 6.8 is restricted to permeable (armourstone) structures under oblique wave attack, while formula 4.25 is for smooth, impermeable slopes.

Neural Network update:
The Neural Network Overtopping tool is freely available now on the Deltares website as a web application. To use this application please visit and start the application by clicking the following link: Open Overtopping Neural Network on this website.  

Further, in case you still want to use the stand-alone version of Neural Network Overtopping Tool, you can download it from the deltares ftp-account. Below you can find information on this ftp-account.

    Host name =
    User name = overtopnn
    Password  = sueu978
    Account   = <leave this blank>
    Directory = <leave this blank>

The URL representation of the account, e.g., for use in a browser, is:

After downloading, please run the setup. This will install/update the files on your system.

For further inquiries, contact Jan Kramer of Deltares