Forest At Stone Oak

I am looking at a home under construction in section 3 which has a drain pipe that comes from under the street draining onto the property (approx. 6' corregated drainage pip). There is no ditch, only rocks which have been placed on the property to help erosion. Is there anyone here that has or knows someone with a drainage easement like this?  If so could you give me an insight on how much drainage to expect and whether or not there have been any problems?  Thank you