What does it mean to carve lotus flowers on the manhole cover?

It means purity and sacredness, and represents beautiful friendship and love.

Lotus belongs to Ranunculaceae, which is the general name of two species of lotus. Also known as lotus, water hibiscus and so on. It is a perennial aquatic herb flower of lotus. Underground stems are long and thick, with long nodes and round leaves. Flowering from June to September, it is solitary at the top of the pedicel. There are many petals embedded in the receptacle hole, which are red, pink, white and purple, or have colored lines and edges. Nuts are oval and seeds are oval.

There are many kinds of lotus, which can be divided into two categories: ornamental and edible. China is native to tropical and temperate Asia and was planted as early as the Zhou Dynasty. Lotus is precious all over the body, lotus root and lotus seed are edible, and the germ of lotus seed, rhizome, lotus node, lotus leaf, flower and seed can be used as medicine. Its character of emerging from the mud without staining has always been praised by the world.

"The next day, the lotus leaves are infinitely colorful, and the lotus flowers reflect different colors in the sun" is a true portrayal of the beauty of lotus flowers. The noble character of lotus flower "straight through, not crawling, not stained with mud, clear but not demon" has always been one of the themes of poets' singing and painting.