So.. How can i import N'hoods from Sims 2 to Simcity 4 to edit them, and then put them back in Sims 2?

I was looking around another forum, and i saw this picture.



My question is how can i make the terrain as flat as it is on the beach in SimCity 4? I've tried, but ingame, the terrain is higher than that, and i can't get it lower..

I was playing on my couple, and they were going down to the beach.. then suddenly i noticed that the water was really high!



I thought it would go away, and i didn't know the lot had dug itself down at that point. But after a while, when my couple had went to bed, looked at the road, and the road was like this..


And i know that above the beach was totally flat! And then i went out of the lot, and to the neighborhood. The lot wasn't low there!

Has this happened to any of you? What can i do to fix it?