Your best bet would be to check with your community development agency and see what the tentative or definite plans are for that area. If there's is already grading under way, it would appear that they had to get permits for the grading. In my experience, there are usually a lot of rumors that surround this kind of activity and the only way you can be sure is by going to the source and find out. For instance, a large piece of property has been in escrow in my area and we all knew that a shopping center with a grocery store was supposed to go in. A few months ago, I heard through the rumor mill that the plans had fallen through. I asked around and got all kinds of different accounts on what was supposedly going on. A call to the planning department was the only way to get the real story. It turned out that the plans for the shopping center indeed had fallen through.