Nice work.
I would add a couple comments to what has already been said on zoning regulations & utilities.
1. Be careful of the wording for sign restrictions. Some may allow you to be a certain number of feet from the road or right-of-way these are two very different things. Also be aware of sight triangles at intersections. Probably worth a talk with the city's engineering department if you want to put a sign near an intersection.
2. Utility depths vary greatly by region. Where I live, watermain is buried 7-8 feet to prevent freezing. In warmer climates, it may be at little as 3 feet. I've even seen exposed watermain in the southern US. But this is just anecdotal, watermain isn't what you should be worried about. Sure breaking a watermain is expensive, but no one is going to die. The catastrophic utilites are electrical and natural gas; they should be buried 3 feet below grade in turf areas, reduced bury is usually allowed under hard surfacing; but I frequently see electrical and gas lines buried as little as 12-inches. There is normally very little oversight of the utility companies when doing their installations. Just one last PSA.....CALL BEFORE YOU DIG!