Create a winding watercourse into your pond with this attractive waterfall. Over 2'6 in length, this durable, black plastic fall will last for 20 years guaranteed. It is relatively shallow so only needs a small flow of water to make it work.cascading water from pond waterfalls disrupt the pond surface releasing additional oxygen, which is essential for fish and plants to thriveour waterfall calculator can be used to easily calculate a recommended flow rate.