Down the drain.

With the lower patio up to a certain level the drains to carry the water from the roof away, hopefully keeping the lower rooms dry so we can use them to store things with out getting damaged. 

First things first, dig a ditch, luckily due to the fact that this is largely infill material this is fairly easy.

Next a little sand to bed the pipe down and enable us to get the correct level. Also running a couple of conduits just in case we ever want to put power or something in the corner of the terrace.

Then re infill and tramp down to cover.  No just the tricky bit at the other end which involves redirecting the exiting drain from the bottom of the ramp so that it flows down and joins this drain. The also involved a bit of hard work chiselling away the rock to get the out flow in the right place and level.

Then just a little infill and a few rocks to make up the wall and job done.