1. Activate Mesh tool
2. create your site boundary with it.
3a. select boundary mesh and activate mesh tool,
3b. press & hold space bar (magic wand),
3c. click on contour line,
3d. select apply to user ridges from pop up box.
----------repeat steps 3 a-b-c-d for every contour-----------------
4. click on any node of contour line and hold.
5. select elevate Z from pet pallet.
6. give Z ht and select apply to all from pop up box.
Hope it helps.