Show #50/6211. Planning And Planting A Garden #4

Consider Drainage, Water Runoff, When Building A Garden

The first thing one must do is survey your property when you're building a garden, you've got to look at the drainage and make sure you accommodate that first or you'll be constantly having major washouts. So, Jim had to start at the top where the manor house is. That is 150 feet above the stream that runs through the valley, close to the Japanese garden, which is in the lowest part of the garden. From there as it goes up it traverse the slopes up to the top at 150 feet, so that means a lot of water. They’re presently standing in a swale, a major swale, where all the water rushes down. All of these slopes in here are feeding water into this drainage area. So Jim had to figure out how to manage all that water. At the top, where the manor house is there is roof runoff and it runs fast. There are terraces, and patios; it hits those and runs off fast. There are gutters that have to empty onto those areas which mean fast runoff. There are walkways that go through, pool decks, all these things one must consider. When you have a walkway, at some point it may become necessary to have pipes put under that walkway to manage water. If so one must think about the sizing of those pipes. At the top there is less water, so he utilized eight inch pipes. (That’s the diameter of the pipe.) As more water is picked on the way down a 12 inch diameter pipe is necessary to carry the water. As the water continues down, like at the top of this conifer garden Jim had to put an 18 inch diameter pipe in to carry all the water from the top already collected from all that land. Above them is another level and from the 18 above to here Jim had to size up to 24 inches. The 18 would have never worked, water would have washed this whole walkway out, the water would have overflowed over the walks and washed the plants out. From this 24 inch pipe right below it goes into another 24 inch pipe that's under that walkway. But below that with all the water now collected he needed to go to a 36 inch pipe to carry it on down to the stream, which goes into the valley. So, it’s important to think about your water. A few days ago, they had seven and a half inches of rain in one day. A lot of rain. If they hadn't put this size pipe in, it would have washed everything out. Jim designed it to be a wet weather stream, but it's also a dry stream. So you've got to make sure you place the rocks properly. The garden has to be thought out for drainage.