Adjustments to the aqueduct trace

The original and final solution for the Cherchell aqueduct. In its first setup the aqueduct was built in the first
half of the first century A.D., probably during the reign of Juba II, king of Mauretania and friend of
the emperor Augustus. Initially it was at least 45 km long and ran from springs in the alluvium of the Oued
el Hachem river at 131 m altitude to the city, making a loop to the south around the Oued Bellah valley
(Oued = wadi / river). A smaller loop went for 3 km around the Oued Ilelouine valley in the east. This aqueduct
reached the city at an altitude of 40m.
Sometime during the second century A.D., it was decided to make a drastic change. The local geology contains
a lot of weak marl and shale, rocks that are prone to creep and landslide, and some of the least desirable
rocks to build on anywhere. The climate is characterized by dry summers and torrential rain in winter, which
makes the danger of soil creep and landslides very high.