Lake Managua

Lake Managua (also known as Lago Xolotlán) is a lake in Nicaragua. Managua, the capital of Nicaragua, lies on its southwestern shore. At 1,035 sq km (400 sq mi), it is approximately 58 km (36 mi) long and 25 km (16 mi) wide. The Tipitapa River intermittently joins Lake Managua to Lake Nicaragua.

Similarly to the name of Lake Nicaragua, its name was coined by the Spanish conquerors from "Mangue" (their name for the Mánkeme tribes) and agua ("water").

Momotombo Volcano is on the northwestern shore, reaching 1,280 m (4,199 ft) above sea level. The lake is economically significant: its waters yield fish and alligators and are plied by shallow-draft vessels.

The lake's mean (average) depth is 7.8 m (25.6 ft), and the deepest point is 26 m (85.3 ft), found in a pit near the volcanic Momotombito Island.

Lake Managua is fed by numerous streams rising in the central highlands and the Diriamba Highlands. A significant part of the drainage basin is located north of the lake and drained by three major tributaries: Rio Viejo, Rio Sinecapa, and Rio Pacora. The total water inputs vary widely within the drainage basin, geographically, annually, and seasonally.

The lake is endorheic, a closed lake system in which evaporation approximately equals inflow, and its water level is primarily controlled by evaporation. However, the level of Lake Managua rises significantly during periods of heavy rain.

At one time, the Tipitapa River drained the lake, which flows into Lake Nicaragua. However, it ceased functioning as a regular outflow by 1850 and now serves as an occasional overflow mechanism.

The highest water level of the lake was recorded during the flooding of 1933. The lake rose 3 m (10 ft) in five days during Hurricane Mitch in 1998, destroying the homes of many who lived on its edge. Even higher flooding occurred in September/October 2010.

Since then, the city has prohibited residential use of the most flood-prone areas with an elevation below 42.76 m (140 ft) above sea level.

Some have described Lake Managua as the most contaminated lake in Central America. The lake has been severely polluted, primarily by decades of sewage being dumped into the lake.

The city sewers have drained into the lake since 1927. It was only in 2009 that a modern wastewater treatment plant was opened in Managua, but it treats only 40% of the city's wastewater.

Today's lake has no stable outlet, with occasional floods to Lake Nicaragua through the Tipitapa River. Pollutants are thus concentrated. Despite the pollution, some residents of Managua still live along the lake's shores and eat fish. About 20 fish species still survive in Lake Managua.

_{Map depicting Lake Managua and Lake Nicaragua}