I am planing on building a washroom in my basment. The problem I have is that I don't have any extising swer or dranage lines where I am planing to build.. I am thinking of using the flood drain line to hook up my dranage and swer lines. Is this a good idea? Do I have to take in to consideration a vent line as well?

What fixtures will your washroom have? This "flood drain line", where does it connect to and what's connected to it at the present time? And yes, you will have to vent your bathroom group. Let me give you a typical basement bathroom rough in. Most bathroom groups are roughed in like this.
Toilet connects to sewer main or the stack vent. Lavatory connects to toilet drain and runs a vent off the top the stubout tee out the roof or revents back into a dry vent in the attic.. The toilet wet vents through the lavatory vent and the tub/shower connects to the lavatory drain and is wet vented by it. This is a normal rough in and is acceptable both by local and state codes and also The Standard Plumbing Code Book.
Let me know about the "flood drain line". Regards, Tom

What fixtures will your washroom have? This "flood drain line", where does it connect to and what's connected to it at the present time? And yes, you will have to vent your bathroom group. Let me give you a typical basement bathroom rough in. Most bathroom groups are roughed in like this.
Toilet connects to sewer main or the stack vent. Lavatory connects to toilet drain and runs a vent off the top the stubout tee out the roof or revents back into a dry vent in the attic..The toilet wet vents through the lavatory vent and the tub/shower connects to the lavatory drain and is wet vented by it. This is a normal rough in and is acceptable both by local and state codes and also The Standard Plumbing Code Book.
Let me know about the "flood drain line". Regards, Tom

Hi Tom,
Thxs for the reply. The fixtures are a shower, toilet,washbasin. The flood drain line connect to the main line. At this time there is only the drain attached to it. Won't the flood drain already be vented?
Regards,
Rohan

" At this time there is only the drain attached to it. wont the flood drain already be vented?"

Not if the only fitting attached to it is a floor drain. A floor drain is the only trapped fitting that doesn't require a vent. No my friend, your basement group will have to go down exactly as I presented it. Since the floor drain's going to be your lowest point in the system you might considder installing a floor drain Flood Guard,(see image) on it to prevent any unwanted back ups.
Good luck, Tom