The great men of the mountain land restoration: Prosper Demontzey
The history of the mountain land restoration (abbreviated RTM in French) services has been strongly marked by a few men with assertive characters and remarkable talents. Prosper Demontzey headed the reforestation department in the Lower Alps before overseeing RTM work throughout France. He wrote extensively to disseminate the principles of RTM and its techniques in the 19th century.
Prosper Demontzey (1831–1898), a leading figure of the RTM
After graduating from the Ecole Nationale des Eaux et Forêts, the French National School of Forestry (ENEF) in 1852, he takes up an adventurous position in Algeria in 1853, where he organises road building and Aleppo pine plantations..
The severe floods in the Alps at the end of the 1850s bring to the fore the need for reforestation in the mountains and the correction of torrents in the Alpine massifs.
Prosper Demontzey, appointed in Nice in 1863, is noted for his efficiency and called upon to head the reforestation department of the Basses-Alpes (Alpes de Haute Provence).
He tackles the department's most dangerous torrents. This large-scale work is organised in several stages:
- First of all, (re) afforestation (by planting, often of black pines) and turfing, sometimes drainage of the catchment areas, installation of weirs and small dams in the lateral gullies.
- followed by the construction of a series of dams in the main bed, forming a staircase that replaces the steep natural gradient with a gentler gradient, known as the compensation slope.
Prosper Demontzey's first major project centres on the Bourget torrent, which flows upstream from Barcelonnette.
In 1877, Prosper Demontzey is promoted to curator in Aix en Provence. He extends his field of action to all the departments in the southern Alps and coordinates work on other major destructive torrents: the Valauria torrent, the tributaries of the Boscodon torrent and above all those of the Riou Bourdoux.
The large dam on the Riou Bourdoux: this large dam, 8 metres high and spanning 80 metres, is an emblematic work of the RTM at the end of the 19th century.
In 1882, he is appointed Inspector General, in charge of supervising restoration work throughout France. His reputation spreads beyond France's borders, attracting specialists from neighbouring countries.
Before retiring in 1893, he publishes technical reference works on mountain reforestation and teaching works, translated in Germany and Austria.
Bibliographic sources
PARDÉ, J. (1998). Il y a cent ans : Prosper Demontzey (1831-1898) et l’essor de la RTM. Revue Forestière Française, 3, 277. https://hal.science/hal-03443481
MÉTAILIÉ, J. P. (1988). Une vision de l’aménagement des montagnes au XIXe siècle : Les photographies de la RTM.Sud-Ouest Européen. Revue géographique des Pyrénées et du Sud-Ouest, 59(1), 35‑52. https://doi.org/10.3406/rgpso.1988.3105
Text written by Pascale Hénaut (INRAE-DipSO).
How to cite: Focus Agate: The great men of the mountain land restoration: Prosper Demontzey, Pascale Hénaut (INRAE-DipSO), january 2024. https://agate.inrae.fr/agate/en/content/focus
