Name of the case study
Maurice Audin Storm Water Detention Basin
Description of context
The Seine Saint-Denis General Council has been investing in the fight against flooding for many years through many and varied operations of storm water management, one of which is the reinforcement of the drainage network by the use of detention basin. The works are opencast, green, covered or wet ponds, covering large areas. The oldest ones, with few exceptions, are closed off (due essentially to security problems, potential vandalism, and maintenance). Today, in densely populated urban centres, these sites are highly sought after. Local people are demanding to be allowed to use these spaces. In some areas these sites which are perceived as not used are not respected and suffer heavy damage. To preserve these infrastructures against vandalism and to propose a better land use, the General Council has decided to open up these sites to the public.
Description of project - background
The Clichy-Sous-Bois storm water detention basin (20 000 m3), called Maurice Audin, belongs to the Department of Seine Saint Denis. A department is a subdivision of France administered by a prefect. This installation was closed off, but nevertheless the place was very attractive for the children who used to play there, and to open gaps in the fence, although it is very dangerous (problems of security: from health risk due to water bad quality up to the drowning risk). Indeed, in densely populated urban centres, this kind of sites is highly sought-after. Thus, local people asked to be allowed to use these spaces.
Description of project - objectives/aims
Remove the problems of security: from health risk due to water bad quality up to the drowning risk), and open up the area for the local people.
Description of project - time interval and stages
A partnership between the Department and the municipality of Clichy-Sous-Bois enabled a rehabilitation of this detention basin. Besides its hydraulic function, it also has a leisure function with playgrounds. Indeed, the new detention basin has 2 compartments:
• A covered part (not accessible to the public) of 3500 m3 was created for frequent rains (return period* ≤ 1 year). This part is closed off and has 2 functions:
- It prevents the playground’s flooding for regular rains
- It enables a pre-treatment by decantation.
• An open zone, liable to flooding, that is only used for flooding one or twice a year. This zone includes playgrounds and sport facilities (see photos below.
Maurice Audin Basin
Maurice Audin Basin. In background is located the covered part of the basin (under the stairs).
The detention basin has yet a double function:
• Hydraulic function
• Leisure and sports.
Pedestrian paths and specific access were developed, and the fence was kept to make the management easier (as a public park).
Moreover, devices have been added to the basin in order to be controlled by real time and Maurice Audin basin belongs now to the whole works managed with real time control process by the department: remote surveillance for the water levels and flows, and remote surveillance release rate. This real time control system allows making the area dedicated to the leisure more secure (in forecasting flooding) and in addition it enhances the sewage system management (water discharges control).
However the problem of the ´project continuity´ was raised in this case. The success of the project through time depends of the cleaning of the leisure facilities and security system maintenance.
(* Return period is a statistical term used to describe the rate of occurrence of a particular event. In urban drainage analyses, it is defined as the average period between occurrences of an event (rainfall) greater than or equal to a given value. For example, a ten year period event is often described as having a frequency of once in ten years.)
Description of project - financing
Description of project - other sectors involved
What tools were used to assess sustainability?
Meetings and inquiries
Real time control system
Click here for a full description (pdf)