If you are looking for a real 1:1 creation of your home town I would strongly suggest importing the heightmap from your town and use it as heightmap for a 7d2d map.
A heightmap could be pulled from this site here:
http://terrain.party/ Then following Red Eagle's map from Image tutorial gives you the basic map:
https://7daystodie.com/forums/showthread.php?103613-Alpha-17b240-Quick-Guide-to-Creating-a-%917-Days-To-Die%92-world-from-an-external-image
Once you have done those steps but cant get the world smooth follow these steps:
1. go ingame and type swa 5 noregion in the console ( f1 ) then wait until it has finished. Go out of the map again and delete the dtm_processed.raw in the world file, then load the map up again and you should have smooth terrain.
If you need to add water there is a guide i've written here which gives a better understanding of water in 7d2d:
https://7daystodie.com/forums/showthread.php?124018-water_info-xml-A-Collective-Understanding
Hope this was of help!