cities could also harvest rainwater by collecting rainwater flowing from a roof or driveway in a receiving container and this water could be used for non-potable activities such as toilet flushing, washing cars or gardening.

How would the previous sentence be correctly capitalized?
Cities could also harvest rainwater by collecting rainwater flowing from a roof or driveway in a receiving container and this water could be used for non-potable activities such as toilet flushing, washing cars or gardening.