Antiquailles flood reduction basin (France)

Challenge the practice is addressing: Prevention and protection against flooding.

Concrete practice to achieve the expected goal: The extraction of usable materials in local construction for 15 years will eventually allow the creation of a rainwater retention basin for the Cadereau d'Alès with a capacity of 1.8 million m³ aimed at protecting the population. Before the project, particular attention has to be paid to the presence or not of groundwater and to the underground hydraulic modifications potentially generated by the development. The hydraulic modification generated by the development will depend on the physical characteristics of the materials used (permeability, storage coefficient, etc.), relationship between the water table and the river which is subject to flooding, local rainfall, geometry of structures made, evolution over time (clogging, etc.). Layout, location and morphology of structures, assessment of clipped volume (during mining and over time) and restitution of clipped volume without impact on the environment have been considered. Hydraulic and hydrogeological studies need to be done upstream of the project to verify its feasibility and define the appropriate characteristics of the developments related to quarrying, as these can respond to flooding phenomena.

Expected impact/goal of the practice: The quarry-basin project, Antiquailles flood reduction basin, has been created as part of the CADEREAU program for the prevention and protection against flooding in the city of Nîmes, which was severely affected by devastating floods in 1988.

Who is the target user group of the practice/intervention or implementing the practice/intervention? This practice is for companies in the extractive industry.