Stormwater Management for the German Embassy residence in Nicaragua
The residence of the Germany Embassy in Managua, capital of Nicaragua, is built on a hill and had problems with their stormwater drainage. Through the tropical climate, there are high precipitations with rainfall of 68 mm each 10 years (duration 60 min). Therefor the existing drainage system has been overloaded; resulting in backwater and a breakdown of a boundary wall. Moreover heavy rainfall leads to erosion and instability of the hillslope.
For resolving the drainage problems a swale-trench system has been suggested parallel to the hillslope and completed with custom throttle pipes in the boundary wall (so-called “Llorones”). This solution guarantees drainage without overflow. There will be no infiltration of rainwater on the slope to secure the hill stability, despite having good infiltration characteristics of the topsoil. Problems with neighboring property caused of the “wild” runoff have been minimized by strong reduction of rainwater to approximately 2.5% of the design rain intensity. In addition endemic plant species reduce soil erosion. In order to fulfil slope stabilization, as secondary purpose, measures like vertical terracing with gabions and slope parallel coconut matting were recommended.