REËNSTOK / Building water tank
Basic information
Project Title
Full project title
Category
Project Description
Reënstok is a building facade water tank for storing roof rainwater.
Rainwater can be distributed either directly to the street to water the vegetation or to each floor to supply the toilets, the washing machine and water the vegetation on the balconies.
Project Region
EU Programme or fund
Description of the project
Summary
Reënstok is a building tank that replaces rainwater downpipes. The rainwater stored in these new kind of buffer tanks no longer goes directly to the sewers. The water is collected and stored for in situ recovery: watering balconies, street gardens and green walls. The use of rainwater is also possible, on each floor, to supply the toilets, the washing machine in addition to the public network. This buffer device also has another advantage: regulator, by absorbing excess water in the event of a storm to prevent overflows from treatment plants and by ensuring a minimum flow for the proper functioning of the sewers in dry periods. Composed of modules, this tank is erected without limit of height up to the roof. This system purges itself automatically in the event of severe frost.
Key objectives for sustainability
The rainwater stored in these buffer columns is intended for various environmental functions. Provide a water point, easy to access, to accompany the revegetation of the streets. And help fight against urban heat islands, a consequence of global warming. Water can also be distributed to each floor to avoid using the drinking water network to water balconies, fill toilet water cisterns and power washing machines.
To ensure durable equipment, we have designed it robustly by choosing stainless steel. Its low-tech design does not require any electronic or electrical component. The water is dispensed by gravity and does not require a pump.
Key objectives for aesthetics and quality
The tank function applied to a facade reveals to pedestrians the facade's capacity to store scarce water in summer.
However, to meet the urban integration requirements imposed by the architects of French buildings, this tank is made up of a simple stack of rectangular parallelepipeds. Thus, we obtain a neutral silhouette, cleaned of all cleavage asperities to make this tank as discreet as possible. The material chosen is a brushed stainless steel which reflects the colors of its surroundings. A specific color is used for the distribution unit in the lower part. Therefore, aesthetics result from the tension between visibility of function and formal discretion.
Key objectives for inclusion
This reservoir is intended for the inhabitants of the city. The distribution system is also accessible to the disabled who wish to obtain rainwater to water the vegetation of the streets.
Results in relation to category
The tank offers a storage volume of 570 liters per floor, occupying a very small surface on the sidewalk (thickness 28cm)
In Paris, rue Louis Blanc, the operating tank has already collected 14,000 liters in 2 years.
How Citizens benefit
To fight against urban heat islands, Paris implemented greening permits in 2015.
It was essential to combine this permit with a solution to facilitate access to water.
Thus, a first Reënstok copy was implemented by Paris within the social housing of Paris Habitat (social landlord of the city of Paris), as part of the creation of a garden at the bottom of the building. Since its installation, the equipment has been acclaimed by residents for free watering in summer, plantings in the garden.
Innovative character
Reënstok is a water tank grafted to the facades of a building (new and old). The water is stored there and distributed by gravity at street level or to each balcony. It is low-tech equipment with no height limit that cleverly manages the pressure of the water column.
