Ocean flooded airport area NTGJ

The FSX NTGJ in So pacific is in/on the ocean (think ac carrier flight deck ~:) I have used ADE175 to create
a coral poly; however the water then just "floods" the coral. Is there any way to get the coral poly to
appear between the airport runways, buildings, etc and the water ?
Screen cap is attached to help illustrate.
Thank you,
Ken Boardman