Thanks Mitchel most appreciated !!One last question . Where im plumbing it into it needs to angle towards the house . should this section (yellow) be ...

digging the trench that close will expose the fence posts (concrete). The 200x50 board will only be max 150mmdigging the trench that deep and close ...

Thanks so much for replying. you are correct i will be usin a 200x50 H4 board. I only needing to notch about an inch off the bottom off the board wher ...

Thanks for you help. The reserve next to my property is very wet during winter and ponds water in this area. Some run off is pushed towards my fence ...