Fluid delivery systems and methods of delivering an agent and treating a disorder are disclosed that include a subcutaneously implantable port having a body defining a chamber with an open top and a delivery opening and a septum coupled to the body to extend over the open top of the chamber. The systems and methods can further include an intrathecal catheter having an proximal end configured to be coupled to the port and fluidly coupled to the delivery opening of the chamber and a plug having a body with a passage to receive the intrathecal catheter therethrough. The plug can be configured to be inserted into the fascia to protect against leakage of cerebrospinal fluid.