A $42-million dam a century in the making could end water shortages for more than half a million Zimbabweans — and win votes for the ruling party in an opposition stronghold that may decide next year’s presidential election. The expected completion early in 2023 of the Gwayi-Shangani dam 153 miles north west of Bulawayo is part of a strategy by President Emmerson Mnangagwa’s ruling Zimbabwe African National Union-Patriotic Front to capture votes in the country’s long-neglected second-largest city, according to analysts. Zanu-PF has traditionally struggled to make inroads into urban areas in the province, an area dominated by the minority Ndebele ethnic group.