What does it mean to open a swimming pool?

Opening a pond means: opening a canal, building a sewer and opening a pond (fish pond). Ponds are smaller bodies of water than lakes. The method of defining ponds and lakes is controversial. Generally speaking, the pond is too small to cross the bamboo raft without using a boat.

Another definition is that people can cross safely without being completely submerged, or the water is shallow and the sunlight can reach the bottom of the pond. Ponds can also refer to artificial pools. Usually, the pond has no water inlet on the ground. They all rely on natural groundwater and rainwater or artificially introduce water into the pool. Because of this, the closed ecosystem of ponds is different from that of lakes. The water in the pond is often green because there are many algae in it.