Error: refined grid in D-Flow Flexible Mesh - Forum - Delft3D

Hi everyone,

I am a user of Delft3D Flexible Mesh and I need to build a refined grid in order to draw five detached breakwaters. My question is how refined can my grid be in order to avoid this error, "FlowFM: Roughness contains unspecific points, the calculation kermel will replace these with default values". I already saw some possible solutions to solve this problem. Therefore, I merged circumferences but it will make my grid less refined... I will show you my case study so that you can understand what I mean.

This is the error on the image "01_Error".

This is my case study, located in Oporto, Portugal (Image "02_CaseStudy").

These are detached breakwaters under study. My main goal is to study the morphodynamic near these five detached coastal protection structures (Image "03_Breakwaters").

As you can see on the following image, the grid zone where breakwaters are going to be implemented is too refined. I am afraid that FM does not support this high resolution (Image "04_RefinedGrid").

I would like to know what can I do to make this study well and solve the problems I mentioned above.

Thank you very much.