China has limited renewable water resources; 11 provinces are already water scarce (<1,000m3 per capita per year) and climate change exacerbates existing water stresses. The government recognises this issue and has responded by setting tough new water quotas, as well as pollution reduction targets. Three sectors will be most affected: power, industry and coal mining. The power sector is heavily reliant on water for cooling purposes, as well as driving steam turbines. Energy efficiency is as important as water efficiency because using less energy would reduce demand for more power, which could lead to less capacity, alleviating some of the water stress. The industrial sector is doubly exposed since it consumes well over 80% of all electricity. China’s power capacity expansion will involve an increase in coal mining.
The City Water Challenge:
The water is a scarce resource. Faced with a growing consumption, water management is an ongoing challenge. En eco-district integrates hydrological site to implement sound management of rainwater to save drinking water and to enhance the wastewater. This theme includes the entire cycle of domestic water in urban areas (capture, route, process, distribute, retrieve, clean, restore). The problem extends management of water as a natural resource and environment as part of near in the cityscape of tomorrow. Finally products of wastewater treatment are considered as a new source of energy “biomass”.
- Developping a comprehensive water cycle approach: Diagnosis hydrological site identifies the water cycle: watershed runoff historical rainfall network watershed, soil permeability, etc.. The objective is to avoid stormwater discharges outside neighborhood. Control their runoff through retention (Green roof) and in situ infiltration. Impermeable surfaces are limited. Management in the open storm water is recommended. Of valleys, gutters, ditches capture and convey the effluents to natural spaces equipped: lake, canal, pond, meadows … The water is filtered and cleaned by plants appropriate, integrated within the filter basins, islands, habitats … These elements are taken into account in the design the ground plane of the neighborhood.
- Limiting the consumption of drinking water: The collection and storage of rainwater will minimize the use of drink water for watering gardens and street cleaning. For example, revegetation flat roofs ensures buffering of rainwater and storage in the islands for watering gardens. In addition, landscaped areas include a choice adapted plant local climatic conditions. Act on the customs of the inhabitants is an important vector reduction of drinking water consumption. Limit the capacity bathtubs or delete, generalize aerators other devices and flow restrictors, decrease significantly consumption at the neighborhood level. Monitoring tools of consumption are established. They provide users with information about their consumption, compared to the average data by type of dwelling. They detect differences in consumption to alert users
and thus rapidly initiate corrective actions.
- Enhancing the reuse of wastewater: Reducing the flow of waste water arriving in the stations purification contributes to limiting the amount of energy required to treatment. Implementation of remediation techniques natural plants (phytoremediation) contribute indirectly. In addition, wastewater gradually as needed true source of renewable energy. Materials processing organic material in the wastewater produced biogas. Systems heat recovery greywater scale buildings or to that of the processing station, allow reuse of calories.