A clear drainage from the nose after a rhinoplasty is called rhinitis and is very common. A CSF leak is extremely uncommon but can occur. There is probably no reason to expect that this is anything other than normal drainage. Your surgeon should be informed as he understands the extent of your surgery and how close he was to the cribiform plate.
It is very common to have congestion and discharge following nasal surgery. I'm not sure if you have internal splints in place or not but splints can cause congestion and a runny nose which improves after removal. Removal is typically after 4-6 days. You should experience gradual improvement in your symptoms over the next couple of weeks. It would be highly unlikely, but not unheard of, for a CSF leak to occur from this type of surgery. Follow up with your surgeon to ensure that you are healing properly.
Having nasal drainage after surgery is to be expected. If you have any kind of packing or splints inside your nose, your body will actually increase the amount of nasal secretions in attempt to help flush them out. A CSF (cerebrospinal fluid) leak would be very rare after a septorhinoplasty but theoretically possible. If it were a CSF leak, the first line of treatment would most likely be bed rest anyways. I would expect the amount of drainage you have would improve after your first postoperative visit. Best of luck.