You can put stones in the swale to slow up the waters movement down hill, like making small dams in streams, some swales are made like this with stones in to slow down flow I have seen photos of them in internet. I think swales are just drainage courses, canals in a small way made by people who want to direct water on their land rather than great canals watercourses that cross a country. THey are canals whose floors have not been waterproffed so they do take up water but not too quickly. That you use them to hold water and allow see pn rather than run off instead of to direct water to where you want it to go or away from something you don't want to get wet, is your affair and a
permaculture irrigation in depth affair.
As the swales are meant to have plants in the bottom of them to sure them up, grasses for example, as are any cuttings in hills made for roads meant to be planted up to stop erosion of the cutting. All easily eroded plaeces should be p'lanted up to stop erosion. Swales are only meant to hold or carry water after it rains not all the time, so grass should be able to grow in them. The plants should stop the water running down the swale if the incline is very small.
Darrel Doherty puts slight downward incline into his swales. If you imagine the line of hills as being scallooped so that if you walked along the bottom of the hills you would be walking in S shaped lines walking round promontries and inlets, well, as the inlets get wetter than the promontories because the slopes face into them as well as downwards not outward towards the most salient bits of the hill. water drains away from the crests of the hills, so daren doherty puts in swales that keep the salaent bits of the hills as wet as wet as the rest of the hill with a slight incline todown towards the most salient parts of the hill .
He says the water only runs down the slight incline of the swale in a specialy heavy water event. So maybe you don't have to worry about the slight incline in normal circumstances.
Darren Doherties idea must be good for keeping the whole slope irrigated but not so good for water harvestring if part of you interest in water harvesting is filling
underground water which happens better if there are pockets of water, puddles where the water seeps in and key points where it collects and seeps in to the ground. If you lead it out to the points that dry mostl easily it will return to the air, evaporate. If its equally distributed then there wont' be so much water just hanging around in key ppints till it sinks in. The water will be more likely to evaporate off the land spread thin. Thats why irrigation is a doubtfull thing, it is better to grow a drier country crop on dry land than to irrigate. Irrigation does not sink into the ground very deeply and evaporates easily.
I have drip irrigation so I do use it am myself am guilty of using it. Farmers however work on a bigger scales than gardeners and if they grow maize instead of wheat here in Spain were summers are dry and maize does not ripen untill late in the year unlike wheat that ripen before the dry season startd, then the farmers are going to use enormouse quantities of water, they are the group who uses most water if i remember right so they need whatching. It should not be have a
shower and not a bath it should be, what are the farmers growing, rice in the deserrt?
You can turn the swale into steps instead of leaving it as a ramp. If the horizontal part of the steps inclines slightly, is slightly lower on the up hill side than the down hill side of the step then the water will collect in the back of the step and sink into the ground at regular intervals.
Just having a bumpy bottomed swale with hollows in it should work, puddling helps water get soaked into the earth instead of running off it . The uneven surface should do the same as backwardly inclined steps would do, it would be to have pools of water that sink into the ground instead of running down the swales. agri
rose macaskie.
