Building a cascade waterfall/feature 1.6m high, 1ft wide approx, how deep should the reservoir be.?

Question:Ok, im building a waterfall water feature in my garden 1.6 m high, 300mm wide approx, im not sure how deep i should have the resevoir. Can any one out there advise me. The water feature comes in 2 parts and im going to add sections of my own, it will be approx 3 metres long. Thanks for looking

Answers:
aini1234

Depth of the reservoir at the spill point is dependent upon the effect you are trying to achieve at that point. The shape of the falling water i.e. sheet or column will also have different impact effects at the fall point in the reservoir. A sheet fall does not need as deep a fall point because the water energy is not concentrated and thus will not create as much turbulence in the fall pit. The angle of the fall pit's floor can also be engineered to dissipate the fall energy, i.e. basin vs flat vs sloped away from the fall.

Experiment with various fall shapes and how they act with various depths and fall floor shapes.

Fall water volume is also a factor. Play with that in your tests. However, I do suppose you have a set output from your return pump unless you can throttle it.

Simple test example. Fill water pail with water. At measured point above fall floor. Pour water from pail at a rate that approximates your return pump's volume. Pour into various containers that approximate the shape and depth of what your fall point in the reservoir will be.

If you want a sheet fall then you will need a knife weir that will be the spill way's sharp edge that creates the thin water sheet fall. They are quite nice as they reflect the most light at night from water feature lighting.