Hello everyone!
I am a total beginner, so there is a big chance for this to be a silly question - I am sorry if I sound stupid.
I want to build a city - much like Venice, and besides roads I want it to have canals - and now the question: how to I build these? Roads are no problem with the landscape spline tool but the canal obviously has a height, too. Is there some way to adjust the height or do I have to lower the terrain by hand along the spline? Im very clumsy by hand and it looks very messy xD
Thank you very much in advance! (sorry for bad english, its not my first language xD )
Hi, you can use landscape splines also to create canals; I’m doing it in these days! Place your landscape splines, set the height position with the Z coordinate of the position in details panel. You can also control the width of the canal with the width of the spline (remembre that 1 uu is 1 cm); moreover you can control the side falloff and the end falloff (set to 0 when 2 canals meet). Then check “Lower Terrain” and uncheck “Raise Terrain” (details panel). It will read the Z value of the spline and lower the terrain accordingly.
One tip: you can set the height of many control points at the same time if you double click the “Control Points” button o the “Segment” button in the spline details, you don’t have to adjust them one by one if you don’t need it (huge timesaving!)
Enjoy! 
Wow! Thank you very much!! I works, thanks so much :* would love to come over and huge you 
Glad I saved you some time! enjoy! 