DAR ES SALAAM, Aug. 14 -- EVERY rainy season, the skies darken and anxiety rises in thousands of low-lying urban neighbourhoods across Tanzania, where residents brace for the familiar threat of flooding.

As torrential rains descend, homes are inundated, livelihoods disrupted, businesses brought to a standstill and the risk of waterborne diseases increases, turning what should be a season of renewal into a period of uncertainty for many families.

In Dar es Salaam, neighbourhoods such as Jangwani, the Msimbazi Valley, Kigogo, Mkwajuni, Vingunguti and parts of Kinondoni have become recurring hotspots.

Heavy downpours, inadequate drainage, rapid urbanisation and continued settlement in flood-prone areas combine to turn rainwater into a des...