This is the finished patio extension. We ran out of large gravel for the end of the channel but the sink is in, plumbed and everything works like a dream. I’ll get back and put some finishing touches on the pillars that hold up the sink and add a backsplash with tile shards and grout, extend the drainage pipe to a catch basin with a valve to divert water to two simple water filter basins dug into the hillside, filled with rocks, gravel and then sand in that order, to filter out toxic particulates from washing paintbrushes, etc. in the outdoor sink. At the base of the hill is a Riparian zone , the river that leads to the waterfalls and swimming hole further down the ravine, so we really want to filter all the gray water we can before it enters the watershed. When it rains really hard the water comes off the roof with an arching trajectory and lands at the outer half of the dark gray large gravel strip. It percolates down into a drainage pipe we drilled a million holes in that carries the water beautifully down the channel parallel to the house and delivers it to a zone well away from the foundation. When I first got here, the outdoor sink zone was a boggy mudhole and significant erosion was taking place. The swampy area was a Dengue mosquito attractor and had to be resolved.
This solution will be improved even more with raingutter, most likely in the near future. For now though, this beautifies the transition of the porch and yard, created a clean zone to take off shoes, buffers and redirects rain splash and drains off all the water where we want it to go, well away from the house. The quantity of water is truly astounding in the rainy season. Just the other day it rained 6 inches in a 3 hour period. Enjoy the Pics, let me know what you think.