In traditional urban city planning solutions, people drain the rainwater out of cites, to avoid any potential threatens brought by excessive rainwater in the city. However, even though it performs well in flood preventing, it will also increase the pressure on groundwater extraction: firstly, drain-off rainwater will slow down the process of groundwater recharging. Secondly, dwellers in the city become more dependent on groundwater as their daily water supply source. However, Hanging Water Tank can improve this situation by their innovations, to change the concept of urban water usage.
If buildings in the city are equipped with hanging water tanks and roof skins, rainwater will be collected in the urban area. Rainwater will be stored on the roof and on the tank located wither on the top or the bottom of the green building, and can be used anytime. The collected water can be applied on urban irrigation, where water can be recharged into the groundwater. The replenishment rising the groundwater level, therefore, plants can grow better since their root system become closer to the groundwater. There are several products of Hanging Water Tank that are used to build up the innovated urban water system: HWT Skinroof, HWT Roof Gutter, HWT Greenroof, HWT Hanging Water Tank, HWT Storage Tank, HWT Drainy Rain-pipe, HWT U-Block Wall, HWT Infiltration Unit, HWT Kerbstone, Wadi's.
The collected rainwater can be used for car washing, plant irrigation, cooling and other purposes, which will largely reduce urban water supplying pressure. Moreover, in this way, more energy can be saved by reducing the demand of water division among different storage reservoirs in the cities. At present, HWT has established a sponge construction research demonstration project in Dalian.
Applications
- Sponge building Plinthos Sweikhuizen
Hanging Water Tank was also applied in the location of Mutsaers foundation, Plinthos in Sweikhuizen. At this location a choice was made for a green roof system with “Sedum Boxes”. This is an uncomplicated system in which all parts of foil, substrate and plant mix are incorporated in a basket and fixed on the roof in a windproof way.
The boxes are hooked together and can quickly be mounted on the roof. The system is easily replaceable and interchangeable and has plenty of good combination options with, for example, solar panels. Soon the construction of the green façade will start, which will further complete the system.
- Sponge building Dalian China
The first pilot of Hanging Water Tank in Liaoning, China was realized in Dalian, with subsidy from the Dutch government.
Hengji Water was the cooperating company that provided a roof for the innovative urban water system. This water treatment company is highly ranked in sustainability and wanted to be the first to have Hanging Water Tank on the roof.
The project started at the beginning of 2017. In April most of the construction works were done by Green Art International. All materials were supplied by local companies.
The rooftop was equipped with three samples of SkinRoofing. The first was just the plain roof with gravel, the second was covered with sedum plants and the third was overgrown with urban agriculture.
In this pilot project the following parts of the HWT-system were applied: SkinRoofing, in three different sections mentioned before, HWT-drainy rain pipe, and a green wall, supplied by Sempergreen. The eventually overflowing water irrigates the surrounding garden with orchards and viticulture. The whole system is equipped with measuring instruments, which can be supervised in the Netherlands via Wifi. The project opened at the first of June 2017 with a festive seminar.
Source: Haing Water Tank