Taxes are obtained by the parish sheriff's office. In Orleans Parish there's a separate treasury department.  In almost all parishes these records are online.  Others can be obtained by phone call.

If there's a drain servitude or easement they're recorded in the clerk of court's conveyance office records.  Judgments -encumbrances - are recorded in clerk of court's mortgage office records. 

There is no earthly reason to go to most parishes.  But some parish records only go so far back so in house search is required. 

That being said, it requires a Louisiana specific experienced abstractor to complete a thorough search, and in Louisiana only an attorney can examine title.