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 North Caribbean Coast Autonomous Region are also connected via road. A third road, currently under construction, will connect Bluefields, South Caribbean Coast Autonomous Region with Managua via Nueva Guinea. Traveling by airplane is more efficient than traveling by these roads due to the poor conditions, especially in the rainy season. Domestic flights are operated by La Costeña from the international airport. There are 36 bus routes in Managua. These are regulated by the city’s regulatory entity for municipal transports (IRTRAMMA) and individually operated by cooperatives and private companies. In addition there are two bus routes that formerly connected to outside