The world’s first Arch Dam- ‘Glanum Dam’, was located on the south west of the French town of Saint-Reme-de-Provence. The dam was also called as ‘Vallon de Baume Dam’ and was built around 1st century BCE to supply water to the ancient Roman town of Glanum. The location of the dam at a narrow gorge (The Gorge of Peyrou) between the hills of Les Alpilles provided an ideal location for the construction of an Arch Dam.

Though the dam was damaged during the construction of a modern dam at same place in 1891; it is established beyond doubt that the Glanum Dam was the first ever known dam of its kind.

Location of the Glanum Dam

The site of the Glanum Dam is located at a distance of 1 km south of the town of Saint-Reme-de-Provence in south west France. The dam was built on a narrow gorge called the Gorge of Peyrou, that cuts through the hills of Les Alpilles; a small range of low mountains in southern France.

The town of Saint-Reme-de-Provence is north to the Alpilles and to the Glanum Dam’s site; and both are almost at an approximate distance of 20 km (12 miles) from the Avignon town. Avignon has an airport and is well connected with Saint-Reme by roads and highways.

Details of the Dam

The Glanum Dam is known to be the oldest Arch Dam built around 1st century AD by the Romans to supply water to the ancient town of Glanum; one of their early settlements. The dam was built on a narrow gorge between Les Alpilles hills just south of Saint-Reme.

The constraint of space in the gorge and the scarcity of construction materials at site, provided an ideal location for an Arch Dam; as they are suitable for narrow spaces and require considerably low construction materials than a full fledge masonry dam.

An Arch Dam is a basically a curved dam that is curved upstream and is thinner than the gravity dams. The dams are designed as such that hydraulic pressure of the stored water pressing against the curved surface, strengthen the structure and also the abutments cutting inside the hills.

The Glanum Dam is reported to be 6 mtr (20 ft) high with a crest length of approximately 9 mtr (30 ft). The dam consisted of two parallel curved masonry walls around 1 mtr thick and space of 1.5 mtr (15 feet) between them.

The masonry walls were built of stones secured with crampons and the joints were made waterproof by using Cordon joints. The 1.5 mtr gap between the masonry was filled with stones and earth.

The dam was designed in such a way that the pressure of the water stored strengthens the masonry as well as the foundation and abutments cutting inside the hills on both the sides. It was surrounded by cliffs and valleys aiming for the collection of rain water in form of surface run off.

The dam had been a true architectural marvel with a width of only 3.5 mtr and located between two hills across a very narrow gorge.

 

The Discovery and History

The remains of the Glanum Dam were discovered by Esprit Calvet (1728-1810) in 1763. Calvet was a physician and a collector (by hobby) belonging to the town of Avignon in south east France.  The dam was built to supply water to the nearby town of Glanum by nearly 500 mtr long aqueduct built especially for the purpose.

Glanum was a fortified town built by Indo-European people also known as Salyes founded in the 6th Century BCE. Glanum officially became a Roman city under Emperor Augustus’ around 27 BCE, but the town didn’t survive the collapse of the Roman Empire and was abandoned in 260 CE. During the Roman Empire the town saw massive infrastructure developments by construction of monuments, sewers, temples also dams and aqueducts to supply water to the town for domestic purposes.

It was among these ruins of the town that Esprit Calvet discovered the remains of the Glanum Dam in 1763.

The Lake and the Modern Replacement of Glanum Dam

The ancient Glanum Dam was destroyed in 1891 when a modern Arch Gravity Dam was built at the same place. The dam impounds ‘Vallon De Baume’ (French) or the ‘Valley of Balm’ resulting in a small reservoir with a capacity of 80000 cubic meters, locally known as ‘Lac du Peirou’. The lake provides a beautiful outing to the locals and is quite popular among them. The way to the lake is south of Saint-Reme in the direction of Glanum.

The lake has derived its name from French word ‘Peirou’ meaning a cauldron or a large pot used to store water.

The modern dam that was built as a replacement to the ancient Glanum Dam, supplies water to a massive fountain in Saint-Reme-de-Provence and irrigation to the southern districts. The height of the present dam is 19 mtrs and the widths at base and crest are 7 mtrs and 1 mtr respectively.

The shore of lake is also home to the red and blue dragon fly which is a major attraction among locals.

FAQs about First Arch Dam in the World

Q1) Which was the world’s first known Arch Dam?

Ans- The Glanum Dam in south west France is the world’s first built Arch Dam.

Q2) Where was the world’s first Arch Dam located?

Ans- The world’s first Arch Dam- Glanum Dam is located at a distance of 1 km from the town of Saint-Reme-de-Provence in south west France.

 

Q3) When was the world’s first Arch Dam constructed?

Ans- The world’s first Arch Dam- Glanum Dam was constructed in the 1st century BCE.

Q4) Who built the dam?

Ans- The Glanum Dam was constructed by the Romans.

Q5) What was the other name of the Glanum Dam?

Ans- The Glanum Dam was also called ‘Vallon de Baume’ Dam.

Q6) What was the main purpose of the Glanum Dam?

Ans- The dam was built with a main purpose of supplying water to the town of Glanum.

Q7) How was the water from the dam’s reservoir carried to the Glanum town?

Ans- The water from the dam’s lake/reservoir was carried to the Glanum town with the help of aqueducts.

Q8) What kind of dam was the Glanum Dam?

Ans- The Glanum Dam was an Arch Dam.

Q9) On the foot of which mountain range was the dam constructed?

Ans- The dam was built in a narrow gorge cutting through Les Alpilles mountain range.

Q10) How far is the site of Glanum Dam from the town of Saint-Reme-de-France?

Ans– The distance between the Glanum Dam and Saint-Reme is around 20 km (12 miles).

Q11) What two factors led to the construction of Arch Dam more feasible?

Ans– Two local factors which led the Glanum Dam to be an Arched Dam were-

  • The narrow gorge between the hills.
  • Scarcity of building materials in the surroundings.

Q12) How high was the structure of Glanum Dam?

Ans– The ancient dam stood 6 meters (20 feet) high.

Q13) What was the crest length of the Glanum Dam?

Ans-The length of crest of the dam was 9 mtr (30 ft).

Q14) How many masonry walls did the Glanum Dam had?

Ans– The dam had two parallel masonry walls.

Q15) How were the masonry walls built?

Ans– The masonry walls were built by stones secured with crampons and the joints were made water proof by using cordons.

Q16) What was the width of the masonry walls?

Ans– The masonry walls were approximately 1 mtr wide.

Q17) What was the width of the space between two masonry walls?

Ans– The two masonry walls had a space of 1.5 meters between them.

Q18) How was the space between masonry walls filled?

Ans– The space between the masonry walls was filled with rocks and earth.

Q19) Which water was collected by the dam?

Ans-The surface runoff water from the valley and the rain water was collected by the dam.

Q20) Who discovered the remains of Glanum Dam and when?

Ans-The remains of Glanum Dam were discovered by a French Physician ‘Esprit Calvet in 1763.

Q21) When was the town of Glanum founded?

Ans– The town of Glanum was founded in the 6th century BCE by Indo-Europeans.

Q22) What was the official period of Roman Empire in Glanum?

Ans– The official period of Roman Empire in Glanum ranges from 27 BCE to 260 CE.

Q23) In which year was the ancient dam destroyed?

Ans– The ancient Glanum Dam was destroyed in 1891 when a modern Arch Gravity Dam was built at the same place.

Q24) What did the dam impounds?

Ans– The dam impounds the ‘Vallon de Baume’ or the ‘Valley of Balm’.

Q25) What is the name of the lake formed by the dam?

Ans– The lake/reservoir formed by the dam is called ‘Lac de Peirou’.

Q26) What does ‘Peirou’ means in English?

Ans-In English Peiroou means a metal cauldron or a large pot which is used for storing water.

Q27) What is the total storing capacity of the dam?

Ans– The total storing capacity of the dam is 80000 cubic meters.

Q28) Where is the water stored by the modern dam supplied to?

Ans– The water stored by the modern dam is used for the fountains in Saint-Reme and also for agricultural purposes in some southern districts.

Q29) What is the height and width of the present dam?

Ans-The present dam has a height of 19 meters, width at base is 7 mtrs and crest width is 1 mtr.

Q30) What are the two distinct species of ‘Dragon Flies’ found near the lake?

Ans– Blue and Red Dragon Flies.