Greywater can be used to irrigate a wide variety of trees and bushes, including many species of fruit trees. The nutrients in household greywater are broken down by microbes living in the mulch basins surrounding the fruit trees, allowing homeowners to grow delicious figs, mulberries, loquats, cherimoyas, guavas, bananas and more.

In areas where greywater is separated from black (i.e. toilet) water to reduce the frequency of emptying a latrine pit, the greywater often flows directly onto the ground surface. There it can form stagnant ponds that increase the risk of illness to residents, especially young children, and provide breeding areas for disease vectors like mosquitoes and flies.

Using mulch basins to trap greywater around fruit trees gives the water time to absorb into the ground. After microbial activity in the mulch basins and soil provides initial treatment to the greywater, it joins the underground aquifer instead of running untreated into the watershed.

Increasing urbanization means that discarded water, containing cleaning product residuals and organic matter, often has less chance to absorb into the ground before entering sensitive habitat or coming into contact with humans. Giving greywater a chance to absorb into the soil not only recharges aquifers but also reduces its impact on the watershed below.