A predial servitude may be established on mortgaged property. If the servitude diminishes the value of the estate to the substantial detriment of the mortgagee, he may demand immediate payment of the debt.
If there is a sale for the enforcement of the mortgage the property is sold free of all servitudes established after the mortgage. In such a case, the acquirer of the servitude has an action for the restitution of its value against the owner who established it.
La. C.C. § 721