Across Puerto Rico, residents are being forced to forgo showers and housecleaning. A restaurant owner in San Juan collects condensation from an air-conditioning unit so customers can use the water to flush toilets. Starting on Friday, the island’s water authority is scheduled to put in place new rationing measures by shutting off water for rotating 48-hour periods in parts of San Juan and surrounding areas. Félix Aponte Ortiz, a leading water management expert in Puerto Rico, says that up to 60 percent of the water in the island’s system never makes it to customers. This spring, the mayor of San Juan sued the Puerto Rico Aqueduct and Sewer Authority over its inability to deal with water outages.