Managua waste water to a new water treatment plant at Las Mercedes in Eastern Managua in May 2009 relieved old concerns over water pollution and native wildlife, and brought some residents closer to the old city center and the rest of the mainland. Managua is located on the southern shores of Lake Xolotlán, also known as Lake Managua. Lake Xolotlán contains the same fish species as larger Lake Cocibolca in southeastern Nicaragua, except for the freshwater sharks found exclusively in the latter. Once a Managuan scenic highlight, the lake has been polluted from the dumping of chemical and waste water since
Managua and its economy. To make matters worse, a series of natural disasters, including Hurricane Mitch in 1998, made economic recovery more difficult. After winning the presidential election in 1990, the National Opposition Union began the reconstruction of Managua began in earnest. More than 300,000 Nicaraguans returned from abroad bringing their expertise and needed capital. Businesses mushroomed, new housing projects and schools were constructed, the airport was expanded and modernized, streets were widened, older malls were repaired and new ones were built, and buildings were cleaned up. In 2006, after the Sandinista National Liberation Front came back into power, literacy, health