Water, a finite resource

This month we observe International World Water Day. Sustainable use and management of freshwater resources is critical because water shortage due to droughts in some parts of the world (time) can cause a shortage of and a rise in prices of food.

The observance of this day was first proposed in Agenda 21 of the 1992 United Nations Conference on Environment and Development (Unced) in Rio de Janeiro, Brazil.

World Water Day was officially assigned to March 22 in 1993 by the United Nations General Assembly. The event is held in collaboration with various stakeholders around the world.

Finite resource. We all know the importance of water and how we should conserve it. Water is a precious and finite resource. Unfortunately, we continue to poison our limited water supply. Our water systems are polluted with industrial chemicals. Human waste, in particular, remains the biggest pollution threat to water resources. Aside from the pollution of our water supply, we have also been very wasteful in the use of water.

Green architecture helps save water. Green buildings are constructed to have minimal impact on the environment, particularly regarding the use of natural resources. In the case of water, green buildings use water efficiently by collecting, reusing and returning water back to the environment.

Green architecture and development may not provide all the answers to the worldwide water crisis, but it can offer many effective ways to help avert the crisis by respecting some of the most basic laws of nature.

Aquifers. Rainwater falling on the ground should be allowed to recharge aquifers and natural waterways without deteriorating their quality or quantity.

Aquifers are underground reservoirs. As water seeps through the ground, soil filters the contaminants before they can pollute the aquifer. Aquifers are refilled by water flowing into recharge areas (such as land with extensive trees and other vegetation). Swamps and water-drenched areas may absorb and collect water that eventually sinks into the aquifers.

In urban areas, where parking lots and roads replace recharge areas and natural ponds, less water reaches the aquifer. Worse still, is that oil from these roads may be washed down by rain and poison the aquifer.

Green architecture addresses this problem by minimizing solid surfaces that may prevent rainwater from penetrating the ground and recharging the aquifer. As more and more urban areas grow, more concrete surfaces cover the ground, preventing moisture from reaching the landscape. These solid surfaces absorb heat during the day and slowly release it at night, contributing to global warming.

Instead of solid concrete or asphalt pavements, porous paving stones or gravel beds can be installed to allow rainwater to penetrate and recharge the aquifer. This will also help cool the surrounding area. Paving stones are precast cement blocks that are laid on a bed of sand to allow rain to seep through.

Water conservation. Green buildings conserve water by installing water-efficient bathroom fixtures, faucet aerators, showerheads and appliances that cut down water use by as much as 30 percent or more.

Rainwater harvesting system. Rainwater harvesting is an environment-friendly way to cut down our dependence on potable water. It involves the use of roof and gutters of buildings and houses to collect rainwater into cisterns. Besides supplying water for washing and watering plants and even drinking, collecting rainwater also helps reduce soil erosion and flooding.

Rainwater can also be collected in wide-open spaces like catchment areas. They may be ponds and marshes and water stored in these areas can then be used for the maintenance of the landscape.

Xeriscaping. Many homes with extensive, manicured lawns keep the plants and the turf grass moist at a very high price due to extensive use of water sprinklers. Watering lawns with treated or potable water is wasteful and energy inefficient.

By selecting the most appropriate type of plants and irrigation equipment, water waste can be minimized considerably. This trend of water conservation through creative landscaping is known as xeriscaping. It does not mean dry landscaping with rocks, cacti and scarce greenery.

Xeriscaping means creating an attractive landscape using plants that are drought-resistant, well-adapted to the local area and chosen for their water efficiency. A xeriscape on the average consumes less than half the amount of water that a conventional landscape does. It also requires less maintenance than turf landscape.

Water reuse techniques. Wastewater from sinks, showers and washing machines can be easily reused so that only treated water can be used for cooking, drinking, bathing and cleaning. Water from these uses called graywater, which can be used to flush toilets and water plants.

Graywater. Graywater recycling can minimize the excessive use of freshwater. It is also an effective purification system.  Since it is not dependent on expensive mechanical equipment, it is energy-efficient. It is also a natural process that does not rely on expensive and toxic chemicals.

For an average family of five to six, a cistern with a 1,000-gallon capacity should be adequate. It can also be mixed with rainwater that has been collected from the roof gutters. By using water from the cistern to flush the toilets, a large volume of water can be saved.

Storm water. Green development relies on natural drainage systems such as the use of swales, an open type of natural drain with turf along the side of the road allowing water to be absorbed by the ground reducing storm water runoff and minimizing chances of flooding.

Wetlands. As rainwater pours down concrete pavements and roads, dirt, engine oil and other chemicals are washed down into natural bodies of water, such as underground water reservoirs. These unnatural elements, when mixed with rainwater, are a major cause of our water contamination and damage to our aquatic life.

Wetlands help reduce the amount of storm water runoff at the same time remove its harmful elements. They reduce flooding by storing storm water and gradually releasing it back to natural waterways. Stabilizing soil also prevents erosion.

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