I want to build a water feature to maximise on the sound of crashing water. Our patio area backs on to neighbours with children and I would appreciate some background noise to block out the din when I sit out there in the summer. The feature would be switched off when we are not outside, I am not that anti-social. I already have a good size pump and could excavate if necessary, but a self contained design would be good, I just want a good waterfall sound.