Managua that Managua will experience a severe earthquake every 50 years or less. Managua features four smaller crater lakes or lagoons within city limits. The most centrally located is the Tiscapa Lagoon in the Tiscapa Lagoon Natural Reserve. Managua, due to its tropical climate, varied topography, naturally fertile soils, and abundant rain and water sources, boasts a great variety of flora. Many different types of trees, some of which are not found elsewhere in the world, appear, including "chilamate"s, "ceibo"s, "pochote"s, "genízaro"s, "tigüilote"s, royal palms, "piñuela"s and "madroño"s (Nicaragua's national tree) surround the city. During the rainy season (May to November),
Managua 1927. A new sewer system and the redirecting of waste water to a new waste water treatment plant at Las Mercedes funded by the German government to decontaminate the lake is expected to be the largest in Central America and was inaugurated in 2009. Managua's city area extends about , essentially south from the south shore of Lake Managua. The lakeshore is at an altitude of above sea level, and the city climbs as it gets towards the Sierras de Managua further south where it is over above sea level. Geologically, the city lies on fault lines, thus seismologists predict