The Brew Cabin

I have a long driveway that slopes toward the house from the road. At the bottom of the drive(which is of tarmac construction) is a concrete section in front of my garage. This concrete section(under a car port) has a drain in the middle of it which I now realise runs into a soak away which is obviously blocked because the area floods and pours into my garage.
I want to lay an Aco linear channel along the front of the concrete section, where it meets the tarmac. This would be approx 5metres in length but is unfortunately level with no drop to where I want the outlet. What sort of drop do I need for this length of drain? To do this would leave a step along the length. I would rather use a channel with a built in drop but these are three times the price of the level ones.
Can anyone help with suggestions of what I should use and how to overcome this problem?

For a 5 metre length, you can lay the Linear Drain (ACO is a brand name) with no fall at all - as long as there is an outlet connceted to a suitable disposal point, water will find its own way out of such a comparatively short length of channel. :)

thanks. that makes life easier and much less expensive!!!!