Contain delaunay with in irregular brep!

Hi guys,

I am struggling with containing this delaunay surface which i am going to use as a toposurface within the site.

Would much appreciate the help!

I have attached my file below.

toposurface (8.5 KB)
topography.3dm (119.0 KB)

You mean something like this?

toposurface (22.5 KB)