As our population grows our demand for space to accommodate new homes, functional agricultural land, and usable amenity space also increases, which in turn puts enormous pressure on land and valuable resources.
Our soil can act as a natural sponge that can absorb normal amounts of rainfall. However, heavy rain can wash away nutrients and topsoil which act as a blanket for our subsoil. Erosion can be reduced by sowing grass or wildflower meadows which meshes the top structure of the soil together. It can slow down surface water runoff which helps to prevent water from eroding soil and other debris into the public domain and causing local flooding. There are several ways in which this can be reduced further.
Planting trees with large canopies, their leaves can help with the slowing down of water hitting the ground. The force of raindrops hitting the ground is greatly minimised allowing water to be absorbed into the ground more efficiently. The tree itself can also absorb water. As it rains, water is attenuated by its leaves, branches, and bark and slowly trickles off into the ground at a more manageable rate.
Creating rain gardens such as those in Grangetown (Cardiff) helps to reduce pressure on existing drainage systems. The use of trees and wet soil tolerant planting help to store water and atmospheric carbon. The water is attenuated at the source and then discharged at a manageable rate into the drainage system. This method also has the added benefit of increasing the biodiversity of the area and beautifying streetscapes, creating a more idyllic and green neighbourhood.
Apartment blocks, within a development, are often required to provide amenity spaces. The design of roofs can be utilised to provide amenity space, attenuate water and provide biodiversity for wildlife. This way space is saved and can negate/ reduce the requirement for swales and attenuation tanks underground.
On a domestic scale, at home, if you live in a location that is prone to local flooding you can try to create a rain garden at the lowest point of your garden using wet soil tolerant planting or if you have space, a tree to help absorb more groundwater. Installing a mini green roof to your garden shed will not only help to improve biodiversity in your garden but also help to absorb excess rainwater, any excess can be channeled into your garden water butt or rain garden.