Note: You can build all the things you want, this was just the basis for a construction you want to do ;)
How set in your world or server:
Step 1: Download a schematic.
Step 2: Put in "schematics" carpet
Step 3: Reload the plugin with "/we reload" or "/worldedit reload"
Step 4: Select a location.
Step 5: Use "/schem load lagoon" command in-game.
Step 6: Paste the tree with "//paste" command.
Step 7: Beware with the Lagoon, needs a considered space.
Be careful! Your server may fall because the Lagoon is very, very huge.