Create a Wandering Watercourse
This meandering watercourse flows between man-made ponds in an expansive garden. Although there is no obvious movement, it is in fact pumped, and aeration of the water keeps it so clear you can see the river stones at the base of the stream. The construction of this wandering watercourse is relatively simple, although it is a labor-intensive project. Pump requirements will depend on the size of the feature.
For a watercourse measuring approximately 5m x 1m (16 ft 5 in x 3 ft 2 in and 800-900 mm (about 3 ft) deep:
600 kg (1 320 lb) cement
0.9 m³ (1 cu yd) sand
0.9 m³ (1 cu yd) crushed stone waterproofing additive
15 liters (3¼ gal) rubberized bitumen sealer (optional)
Step 1. Lay out the watercourse in keeping with the landscaping plan of your garden as a whole. Mark it in some way, preferably with builder’s line or string and pegs. Alternatively, lay out the course with river stones.
Step 2. Dig out the soil to a depth of 1 m (3 ft) ensuring that the sides of the excavation slope gradually outwards (or you will find it difficult to line with con- crete without additional reinforcing or shuttering). Remove the soil.
Step 3. Compact the excavation well with a punner.
Step 4. Now mix the concrete in batches in the ratio 1.2.2 of cement, sand and stone, and then add the waterproofing medium and water. Note that the quantity of waterproofing medium will depend on what you are using; follow the manufacturer’s instructions.
Step 5. Line the excavation with a 100 mm- (4 in-) thick layer of concrete; flatten and compact it as described here: Informal Koi Pond.
Step 6. After at least 48 hours, when the concrete has thoroughly set, you can paint it with bitumen. This will be an additional precaution against water leaking.
Step 7. When the bitumen is dry, line the walls and basin of the concrete course with river stones. Lay them like a dry stone wall, with the larger ones at the bottom and smaller ones on top.
Step 8. For a natural look, you will need to plant marsh-loving species along the banks of the watercourse. Grasses may be encouraged to grow up to its edges. You could also build a simple bridge to enable you to cross the stream at some point.