We are trying to get an understanding of some very important aspects of our garden, which are essential to a successful desert garden. Namely the irrigation and drainage. Not a very exciting topic, I'm sure you will agree, and will probably be of little interest unless you too are facing a new old garden. I am writing it as a reminder for my future forgetfulness. In a desert garden, even one with cactus and succulents, some irrigation will be necessary, especially with new plantings. And with monsoon rains which come in the summer, there had better be a way to get water out of here. If only we could capture it. It will only be possible to do so in small quantities as we just don't have the space for large tanks. Nor would our close neighbors appreciate their presence. We may put in one small rain barrel (wishing I had brought mine with me).
We began by trying to understand the outside system of pipes which include a water softener and multiple pipes and shut-off valves. We now have an understanding that our irrigation system is run on hard water (relief) but not the outside faucets that come from the house. There is one faucet on this pipe work which is before the water softener which will be useful for watering by hand.
Everyone had been saying that i would eventually kill all my plants if I used the softened water. Apparently using potassium rather than sodium to soften the water would be better for both people and plants. We will look into that.
We also learned that the large pipe going into the house is for our in-house sprinker system. We have never had one of those before but they are required here. Fortunately they are unobtrusive flat discs in the ceiling.
The previous owners were taking no chance and put in a reverse osmosis system under the kitchen sink. I have never bought bottled water as we did have filters on our drinking water in the last house but I guess now we are triple protected.
Our attention now turned to the irrigation system which had been coming on every day, dripping for short periods multiple times. Finally, after some heavy rain, I said let's just shut it off for now until we understand all the drips. So many of them had no plant anywhere near them so I capped a number, and others had clearly been chewed by varmints. When we finally got around to checking which program was linked to which drips we discovered that most of the buttons on the main control box were not working! So we had to replace the front panel. Very quickly and efficiently done on line but still quite expensive. We now have a working system but must investigate the best way to irrigate for soaking. The soil is basically desert soil. And finally we must check out all those drip lines to find which work, which don't and which are redundant.
This must be the way commercial companies install install their irrigation lines, possibly as a protective mechanism against rodents who like to chew them to get at water. It was prevent leaks.
Most of the roof is flat and water comes off by way of scuppers. When we had a rain 2 weeks ago we discovered one of the scuppers was causing a problem. The water splashing down on a decorative overhead was being deflected to the patio door and finding its way into the house. So we deemed the solution to be extending the scupper further out. It has been ordered and David will attempt to install it. We had to buy a new ladder as David sold all the ones we had before we left!
Rain from multiple scuppers around the house either drops directly onto the paving or rocks which feed into drains. That was the next job. Over time the wet weather drainage system has filled up with sand and is not flowing well.
We investigated the 4 large grids, two at the back of the house and two down the side. They had standing water which we will have to watch closely and keep fed with mosquito dunks. David used a hose to determine what was going on and where the water was coming out. Suddenly water started coming out at the bottom of the driveway running into the street. A neighbor came over to warn us that we might have a leak!
So this is the boring but necessary investigation we have been working on. Although I have instructed the removal of a large agave and also a little leaf Cordia, Cordia parvifolia, which was hampering our passage down the side of the garage. The information that came from the landscaper says little or no pruning necessary on this beautiful evergreen shrub. The one we removed had been horribly hacked and was in terrible shape. I think I can find a better replacement. Then I discovered an Anacacho orchid tree, Bauhinia lunarioides, poor thing. It was fighting for its life beneath a Texas Olive, Cordia boissieri, A tree hacked into a shrub. Shame on you landscape designers for your thoughtless plantings.