This year’s World Water Day focuses on the ‘Water and Jobs’, highlighting the impact of quantity and quality of water to the lives and livelihoods of workers, and eventually societal and economic transformation. This also calls for a refined focus on the alarming imbalance between the increase rate of water demand and the decreasing water supply – and how this may affect the workers’ lives around the world. This encourages us to take a closer look at water use and its efficiency in the area of buildings – where workers spend most of their waking hours.
Most buildings rely on the city’s water source to meet operational needs; from sanitary necessities, restrooms, heating and cooling, to landscaping. By 2050, global water demand is projected to increase by 55% with regards to the ‘use’ of water and water ‘users’, signifying that demand for water has indeed become one of the building’s major challenges largely attributed by the rapid growth in population and urbanization across many regions.
Water efficiency or water saving methods is also one of the vital indicators in most green buildings ratings – including :
LEED, one of the globally accepted rating system introduced by the U.S. Green Building Council.
LEED identifies four key types of water: Potable Water, Graywater, Black Water and Process Water, all of which provide different utilities in green building water efficiency processes. In the LEED-NC (New Construction) scheme, water efficiency measurements in neighborhood developments is designed to reduce overall water consumption through irrigation and fixture usage.
Water conservation technologies and methods for buildings
Many technological improvements have been introduced to focus and increase water efficiency in a building, including efficient plumbing fixtures installation, non-potable water usage, submeters installation, the use of plants, xeriscaping, and selecting the most efficient irrigation technologies. Another way to save energy in water supply process is by retrofitting wastewater facilities.
Water conservation technologies and strategies are often the most overlooked aspects of a whole-building design strategy. Meanwhile, the planning for various water uses within a building is increasingly becoming a high priority. Water conservation in a building is measured and divided into several categories such as domestic water, HVAC and landscaping.
Domestic water consumption is significant in terms of water usage in a building. A few changes and upgrades in water appliances such as faucets and flush valves can reduce the water consumption in every use.
Heating, Ventilation, and Air Conditioning (HVAC) equipment may also use a considerable amount of water in a building, ranging from 10% to 25% of the total building’s water consumption. In big commercial buildings, water for cooling towers accounts for the biggest part of the HVAC system’s water consumption, so most of the water use reduction effort in HVAC leans mostly towards the improvement of cooling tower performance.
On the other hand, water efficient landscaping practices – to which many referred as Xeriscaping – are also an important target for water conservation measures. A few methods to reduce the water consumption in outdoor areas may include soil analysis and improvements, appropriate plant selection, and efficient irrigation – of which the latter can now involve system controllers such as rain and soil sensors.
Water efficiency not only can help mitigate the rate of water demands, it also helps reduce the energy use and operational costs in buildings. Some cases of high performing green buildings even deliver up to 39% less water use through different methods of water efficiency and conservation. Regular programs to increase awareness towards wise water use, such as World Water Day is therefore vital to encourage more, constant, and gradually impactful actions – especially when implemented collectively.