Help with patio drainage

[Michaelsf90]

The weather has been terrible the past couple of days but I'm wondering how to go about stopping the patio from flooding. It only does it when its really bad weather. Usual rain it's fine. Very heavy rain or heavy rain for a few days and it floods. Its clay heavy soil. The patio sloped to one corner away from the drain on the corner of the house. Under the bench is where it drains to. In that corner I dug down and filled with pea gravel. Now I feel I have 2 options. I'm putting guttering on the shed and water butts which will help. Also the stone gap I am digging soil out and putting sharp grit sand underneath. Then I plan on laying 2 metres of aco drain and draining into the soakaway. Digging the soakaway deeper and filling with loose brick. Also in the corner the last 4 flags aren't laid right. Lay them proper and put sand underneath. I don't expect a miracle but I'm guessing it would help

My other option is the drains go out to the back street. So dig down and see if the iron cast drain goes straight and how deep it is. If its iron cast underneath could I piece an aco into a foul drain? It's a combined sewer in the backstreet

 

[^woody^]

Change that downpipe connection to a gully?

 

[Michaelsf90]

All the drainage is at the top of the patio where the house is. The patio slopes down and away from the house. If I dig down in line with the iron cast and find it is it possible to connect an aco to a foul drain? Or am I better putting sand down instead of soil and trying to improve natural drainage by removing the clay soil? In that corner under the bench where its worst I'd dig the pit deeper and fill with loose brick instead of gravel. Only gravel the top bit so there is more room for the water. Sharp sand should help the drainage. But if i can somehow get the aco drain to piece into the main drain. I plan on laying the aco at the bottom of the patio where the pea gravel is