This research project's objective is to determine volumes of water run-off of roadway in order to define the bases of hydraulic dimensioning and the practical realization of the following works, works of retention, mud tank, basin of retention/infiltration. Further it is aimed to create the bases for a new standard.
To meet the objectives, the methodology should be able to:
- To integrate different methods of sizing retention and treatment of floor water works, including the introduction of a method close to the reality of events (unit hydrograph, continuous simulation, rain series)
- To define the procedures, hydrological principles, hydrogeological and computational techniques to be selected based on the problems and the situation and identify the various types of structures
- It can be checked by any sensitivity study the rainfall system / watershed / road / flow / infiltration system and / or retention
- To allow verification and study of the consequences of overflow storage basins (retention, infiltration)
- To ensure the implementation of the "Instructions" 2002 SAEFL
- To give constructive guidance on the various works to achieve namely retention structures, infiltration and retention basins combined / filtration
The following constructions have been chosen, described and analysed:
- Pretreatment constructions: sedimentation and decantation basins, parting slats, gravel filters;
- Retention installations: retention basins, retention-filtration basins, collector storage;
- Treatment and purification installations: retention-filtration basins with soil and vegetal filters, basins with sand filters, basins with sand and reeds filters, basins with splitt filters, basins with splitt and reeds filters, filtrating ditches.
For each solution, the paper gives precise information on hydraulic parameters (volume
and surface), filters’ data including their vegetalization, the way in which such a project
should be led, an estimation of the efficiency and the returns and some issues related to
the exploitation of the installation and its maintenance.
More precisions are given on the complex filtering structures as well as on the vegetalization
and the reeds’ plantation.
Finally, it is important to point out that the project manager will chose an epuration system
that can be a mix of various structures. It is what is called, in French, a STEC (System for
cleaning and treating road-water).