On a summer evening in the garden, listening to the soft splashing of a source stone – pure relaxation! The best thing is: the water feature not only enhances the garden visually and acoustically, but can also be installed with a manageable effort and expense.
A wide variety of stone types are suitable as source stones. You can use a large field stone (boulder), but also one or more broken or cut sandstones.
Basically, you should make sure that the stone matches your house and your paving stones in the garden: boulders made of granite harmonize very well with the North German clinker brick and brick architecture, sandstone, on the other hand, fits better in Mediterranean-style gardens. Well stones made of broken sandstone can also be integrated very well into a rock garden or gravel garden, while spherical or cuboid sawn, polished stones are better suited for strict architectural garden design. Old millstones are also very popular as source stones. They also have a hole in the middle, so you don’t have to drill through them.
How do you drill the hole in the source stone?
The size of the hole in the stone depends on the outside diameter of the pump’s riser pipe. You have to be able to get through it comfortably, but it shouldn’t have too much play either. You can order the drilling from the stonemason or do it yourself with suitable equipment. Depending on the stone and hole diameter, you need a powerful hammer drill with a long drill tip for concrete masonry.
Important: Place irregularly shaped boulders exactly as they should later be in the garden and position the drill exactly vertically. When drilling in stone or concrete, the “beautiful” side is always the side on which the drill is attached, because when hammer drilling the edge of the drill hole breaks off more or less strongly on the underside. If the drill bit slips off when you insert it, simply make a small indentation in the stone with a sharp chisel. Give the hammer drill a little break when working with large, hard stones such as granite or basalt so that the motor does not overheat. To cool the drill bit, you should also trickle water slowly and steadily into the borehole.
How does the water cycle work with the source stone?
The heart of the water feature is the pump. It is usually installed as a submersible pump (e.g. Oasis Aquarius 1000) in a water basin and pumps the water upwards through the source stone via a thin riser pipe. The outflowing water flows down the stone and is caught again by the basin, creating a closed system. Nevertheless, there is water loss through evaporation and splash water, which must be compensated from time to time.
Tip: The pump should be operated with a float switch (e.g. Gardena 1735-20). It interrupts the circuit as soon as the water level is too low so that the pump does not run dry and is damaged.
Cross-section through a water feature with source stone: 1) floor, 2) filling sand, 3) masonry bucket, 4) water, 5) U-stone made of concrete, 6) submersible pump with riser pipe, 7) cover grille, 8) source stone, 9) decorative stones or gravel
How do you build the water reservoir for the source stone?
First, dig a hole for the water basin. It is best to use a large plastic masonry bucket – it is inexpensive and very solid. Fill the bottom of the hollow with about 15 centimeters of filling sand or mineral mixture and compact the whole thing with a pounder. The sole must not give in later because the entire weight of the system rests on it. Insert the masonry bucket so deep that the upper edge is flush with the ground level and align it horizontally with a spirit level. Then place an upturned concrete U-stone (from the building materials trade) in the middle of the basin. It should be about level with the edge of the masonry tub – if necessary, you can place wooden boards or stone slabs underneath to achieve the appropriate height.
Only now is the water tank covered with filling sand all around so that it has a good connection to the bottom. First fill the masonry bucket about halfway with water and then sludge it from the outside accordingly high, because this way it cannot float up. Repeat this process one more time until the bucket is filled and completely surrounded by sand.
Now cover the masonry bucket with two long, close-meshed grids made of galvanized steel. Important: Saw a rectangle out of each grate at the same height on the side and place the grates next to each other on the masonry bucket and the U-stone so that the two rectangular recesses form a square opening through which the submersible pump fits. This maintenance opening must not be covered by the source stone and should be positioned so that you can conveniently place the submersible pump in the middle of the U-stone. You can simply lay the power cable out through the gap between the two cover grids.
What do you have to pay attention to when installing the source stone?
Now the source stone is placed. Place it on the metal grid exactly above the U-stone and make sure that the hole is not covered by the bars. If the stone wobbles, stabilize it with wooden wedges. Now guide the riser pipe from above through the hole and then put it in the water basin on the previously placed submersible pump.
Tip: Instead of a pipe, you can also use a longer hose, because you can connect it to the pump outside of the water basin.
After a first test run, the technical part of the installation is finished. Now more stones of different sizes are placed on the grid until it has completely disappeared. You should simply cover the maintenance opening with a suitable flat stone. If you want to cover the area with smaller pebbles, you must of course first lay a close-meshed wire mesh or a plastic fleece on the grid. A fleece has the advantage that the water flowing back is continuously filtered. It also suppresses the weeds around the water basin at the same time. But be careful: Depending on the amount of water flowing back, it may not seep away quickly enough and run off above ground. Depending on your taste, you can add a stone edge around the source stone or simply let the water feature merge into the garden without an optical closure.
You can find more great garden design ideas in our ebook. This contains detailed plans that make it easy for you to do all the projects yourself! Check it out, it’s guaranteed to be worth it!