DAR ES SALAAM, Feb. 26 -- EACH year, as skies darken and the long rains sweep across the country, millions watch precious water rush from rooftops into drains and disappear. Weeks later, many of the same communities queue for hours at public taps or wait for water trucks. This cycle is no longer acceptable.

The Ministry of Water has worked hard to drill wells and extend supply networks, but infrastructure alone will not secure our future. Education must flow alongside water. Providing water is essential.

Teaching citizens how to harvest, treat and preserve it is transformative. When households understand how to capture rainwater from roofs, store it safely in tanks, and disinfect it properly, they reduce pressure on public systems and p...