A charity fundraiser hosted a school assembly when she collected a cheque for £925.
Pupils at Witham Hall School raised the money from a series of events last term including a disco, concert and play.
WaterAid fundraiser Anne Lawson gave a presentation about the work of the charity when she visited the school.
She said the money will pay for toilet blocks in two schools in Mali, as well as hand pumps for two villages.
Headteacher Charles Welch said: “We are grateful to Mrs Lawson for her engaging presentation and to members of the school council for their energy and enthusiasm for this fundraising appeal.”