Portuguese to English Tech/Engineering Construction / Civil Engineering

Hi,

I do not understand very well this part of the sentence: desaguando nas descidas de água em concreto armado

Sistema de drenagem superficial composto por drenagem na própria berma, com revestimento em laterita compactada (camada de 30 cm) desaguando nas descidas de água em concreto armado localizadas a cada 400 metros, sendo todos os dispositivos de drenagem dimensionados para Tempo de Retorno igual a 1.000 anos.

Intento: Surface drainage system composed of a drainage system in the berm itself, covered with compacted laterite (30 cm layer), it flows over the water falls? in reinforced concrete? located at each 400 meters, and all drainage devices are sized for the 1000 year return period.

Thank you in advance for your help.