Stormwater is generally of a higher water quality than wastewater. Reuse of stormwater can take mainly place at household and municipal level.

Household level: Householders can use stormwater by collecting roof run-off in a tank for use as drinking water, flushing toilets or for irrigation of the garden (rooftop harvesting). The first flush of roof run-off can be contaminated by dust particles, leaf litter and animal droppings. The first flush can be simply diverted using a simple diverter. A screen can be placed at the inlet to the tank to filter gross particles. Water for drinking will still need to be boiled to denature pathogens. Water from the roof can be directed to the garden beds directly rather than through soakways, and in this way shallow rooted vegetation can benefit from the water, especially in arid regions.

Municipal level: At the municipal level stormwater can be stored in ponds for use for irrigation of parks and gardens and for fire-fighting purposes. This is in addition to employing the ponds for flood control and for improving the amenity value of the water. Other uses are for groundwater recharge, either as a means of storing water, e.g. during the rainy season, for withdrawal in the dry season. Groundwater recharge can also be used to prevent encroachment of seawater near the coast where there is heavy groundwater withdrawal in excess of natural replenishment by precipitation.

(UNEP 2000)