Paved driveway - Drainage problems

[dabull_1983]

Hello. My parents recently re-paved their driveway. Unfortunately no one remember to slope the driveway for water drainage until it was too late. Its a 100ft. long, 20ft wide and contained on either side by 2ft concrete sidewalks.
It slopes away from the road and straight into the garage. Thankfully it doesn't drain towards the house, which is right beside the driveway. I figured out the slope is only about .57 degrees. They installed a non sloped drainage trough 5 inches wide by 20 long, along the width of the driveway, approximately 1ft away from the garage doors. it drains ok until the torrential down pour comes and then the water fills the trough and runs straight into the garage.
My question is, Can they get enough drainage for a driveway that size with just a 5 inch trough provided it has slope? I have found pre-sloped drainage troughs from Watts Water Canada but it's only 4 inches wide. Will that and the slope of the trough be enough to carry water off the driveway in even the severest of downpours?????

[seanandruby]

was the below ground drainage already in, if so what diameter pipe is it? If your contractor placed it, also what diameter is it? Is the gully free from silt? Where does it drain to, soakaway, or into the main sewer? Is the pipe backfalling?

[rab1]

post a picture mate :;):