There was originally an electric water heater in the garage.  The owner installed a gas water heater.
The vent pipe was routed along the ceiling over the garage door.  There should not be elbows in this
pipe right over the water heater.  



The vent pipe has no ‘rise’ on it, so it will not draft properly and allow carbon monoxide to enter the garage. 
The vent pipe should have one inch clearance to combustible materials, including drywall.  Installing metal flashing
between the vent pipe and drywall does no good- the metal will conduct the heat to the drywall.  



I have encountered minor site drainage issues.  In this home the front yard has washed onto the driveway. 
The soil has eroded from under the driveway- the large rocks were originally against the driveway.  



This was a deep rock lined swale in the right yard that has completely filled in with soil.  
The left yard has washed away- the black pipes used to be underground drain pipes.