By Paulo Prada RIO DE JANEIRO (Reuters) – In March 2003, three months into her tenure as Brazil’s environment minister, Marina Silva gathered a half-dozen aides at the modernist ministry building in Brasilia, the capital. She told them the new government of President Luiz Inácio Lula da Silva was about to embark on a pharaonic infrastructure project for Brazil’s arid Northeast. The project, a still-ongoing effort to reroute water from one of Brazil’s biggest rivers, had previously been opposed by environmentalists, including Silva herself. …