Why is it called Chemin du Murmure des Eaux? This path whispers tales of Marseille’s quest for water. Marseille is a vibrant port city in southeastern France. It faced acute water shortages in the 19th century. The population grew quickly. This caused health problems like cholera and typhoid fever.
Before the Canal de Marseille, water resources were limited. An old aqueduct supplied water from a small river. People relied on karstic springs and wells. The groundwater was often poor quality.
Then came Franz Mayor de Montricher. This Swiss civil engineer built the Canal de Marseille. It was operational by 1847. The 80-kilometer canal brought water from the Durance River. This dramatically improved Marseille’s water supply. The Canal de Marseille runs from the north to the south of the Bouches-du-Rhône department.
The municipal council was relieved. The canal provided almost unlimited water. The flow rate varied between 7 and 10 cubic meters per second. However, new environmental issues arose. The water from the Durance River was heavily loaded with sediment. Erosion in unvegetated marlstone areas caused this. The hard water was difficult to use for drinking. It was also unsuitable for industry and watering crops.
In the 1860s, the canal water was turbid about 270 days a year. Mr. Pascal, a local engineer, described it as ugly blackish mud. It flowed with difficulties in pipes.
Five storage reservoirs were built. These were intended to allow sediment deposition. But they were badly designed. Their capacities were too low. They became unusable after a few years. Only the Réaltor reservoir continued to function. Even this was limited. Desilting campaigns failed to prevent siltation.
The first mechanical water filters were located below the central distribution tank. They were clogged by 100000 cubic meters of silt annually. They were abandoned in 1863. The municipality faced high costs. Conflicts arose with residents and fishermen. They complained about hazardous discharges. Some ponds accumulated sediments. This caused noxious emanations and health problems.
City engineers decided to construct a new structure in 1875. It was a reservoir and sedimentation tank. It had a pioneering desilting system. It was built 300 meters south of the Durance River. It was in the small valley of Saint Christophe.
Construction took place between 1877 and 1882. The infrastructure had a storage capacity of 2000000 cubic meters. It is still used today. It efficiently controlled suspended sediments. It solved water clarification problems. The bottom was covered with ditches. The circular channel made hydraulic desilting quick and powerful.
The problem of suspended sediments persisted. Efficient mechanical water filter systems were implemented in 1934. They were located at storage reservoirs in Marseille. They were also at different points of the aqueduct.
So, as you wander along the Chemin du Murmure des Eaux, remember this story. It’s a story of innovation and perseverance. It’s a story of how Marseille secured its water supply. It’s a story etched in the very stones beneath your feet.