Symbolism, Imagery, Allegory
At the start of the novel, the narrator tells us that the land of the Umzimkulu valley is growing "red and bare" (1.1.3). And throughout the Ndotsheni chapters in Book 3, people complain of drought. But then, when Jarvis arrives in Ndotsheni to start planning for the dam, there is a sudden heavy rainfall.
This storm symbolizes the renewal that Jarvis's cooperation with Kumalo brings to Ndotsheni. After this visit between the two men, the drought that has been choking Ndotsheni's farms finally ends. The narrator comments that "there is something new in this valley, some spirit and some life […] Although nothing has come yet, something is here already" (3.35.6).