Need opinion on a ranch property

[Aater Suleman]

This is a property I can purchase but unable to decide if I should or not. Its a farm house on a 17-acre lot. I have found everything to be positive: 17 acre flat lot, 1100 ft county road frontage, future highway expansion running close, good quality house and many improvements like RV parking, an oversized barn, many small sheds, a guest quarter, etc. Light to No deed restrictions. City water available. City sewer about 2 miles away but expanding this was rapidly. 

Given all of this, my plan  live here for 5-7 years and once sewer and the highway arrive, develop or sell. I expect good returns if this plan works out. 

Now the bad part: The property is NOT in a FEMA flood plain however, close to the North eastern corner of the property, there is a wetland that flows flows when it rains heavily. See attached picture. It seems about 70 ft wide and 1-2 ft deep. According to the owner he only sees water there once every few years. They are not required to buy flood insurance but they keep it and pay $300/year.

I do not know how to change my analysis of the market value to reflect this wetland issue what real impact will it have on my plan to subdivide 7 years from now. This is my first project of this magnitude and I am loosing sleep over it. Any guidance will be much appreciated.