Moving towards a sustainable resource future: water conservation, groundwater management, recycling, ‘grey’ water
Sustainable development - Development that meets the needs of the present without limiting the ability of future generations to meet their own needs.
Sustainable water supply - Meeting the present-day need for safe, reliable, and affordable water, which minimises adverse effects on the environment, whilst enabling future generations to meet their requirements.
With growing numbers of people on our planet, it is essential that clean water is provided to people across the globe in a sustainable and fair manner. We need to use water efficiently and to achieve water sustainability we need to;
• Make sure there is a balance between what is consumed and what is used
• Ensure that water remains of a good quality and avoid pollution of our water sources
• Allow for stores to be built up for drier periods in our changing climate
• Manage the water that falls in places effectively
If we can do this we will have sustainable water supply which meets the present-day need for safe, reliable, and affordable water, which minimises adverse effects on the environment, whilst enabling future generations to meet their requirements.
Water conservation is about the strategies needed to protect our water resources. It involves the preservation, control and development of water resources, both surface and groundwater, and prevention of pollution. Water conservation strategies are used to use water more efficiently. As we have already seen, population size, household size and level of wealth all affect how much water is used. Factors such as climate change have increased pressures on natural water resources especially in manufacturing and agricultural irrigation.
Drip irrigation used on vineyards in Rio Arriba County, New Mexico. 2002. Photo by Jeff Vanuga, USDA Natural Resources Conservation Service.
We also need to consider groundwater management, the regulation and control of water levels, pollution, ownership and use of groundwater.
When it rains some water infiltrates the soil and goes underground. This water is known as groundwater. This vital water source can be managed by;
1. Preventing contamination of groundwater which causes the groundwater water supply to not be able to be used as resource of fresh drinking water.
2. Limiting use of groundwater so that natural regeneration of contaminated groundwater can takes place. Excess pumping of groundwater leads to a decrease in groundwater levels and if continued it can exhaust the resource.
In the UK, it is the Environment Agency who have the responsibility of managing ground water in the UK.
Methods to conserve water include;
|Harvesting rainwater||Household management||In farming||In businesses|
Digging ponds, lakes, canals, expanding the water reservoir, and installing rainwater catching ducts and filtration systems on homes are different methods of harvesting rainwater. Harvested and filtered rain water could be used for toilets, home gardening, lawn irrigation, and small scale agriculture.
Water butts and guttering can be used to collect rainwater.
Water use in the household can be reduced by using;
Low-flow shower heads
Low-flush toilets or dual flush toilets (these use up to 67% less water than conventional toilets)
Reuse of greywater for flushing toilets or watering gardens
High-efficiency clothes washers
Drip irrigation for watering gardens rather than sprinklers
Farmers could switch from using open canals and flood irrigation. These are poor for water use as they are often very uneven in distribution, as parts of a field may receive excess water. Lots is lost to evaporation too. Overhead irrigation is slightly more efficient, using centre-pivot or lateral-moving sprinklers, as it has a more equal and controlled distribution pattern. Drip irrigation is the most efficient, most expensive and least-used type, but offers the ability to deliver water to plant roots with minimal losses.
The use of Hydroponics where crops are grown in greenhouses with containers full of water and nutrients.
Businesses can save lots of water too. Many water-saving devices (such as low-flush toilets) that are useful in homes can also be useful for business water saving. In addition Businesses could use;
Waterless car washes
Infrared or foot-operated taps
Water-saving steam sterilizers, for use in hospitals and health care facilities
Rain water harvesting
Recycling water is another solution where water that has already been used is reclaimed and put to another use. This is often done with sewage and drainage water that has been filtered and treated to get rid of solids and impurities. It can then be used to;
• Recharge ground water aquifers
• Irrigate fields for farming
• Cool industrial processes
• Top up rivers
One type of recycling of water is to use “Grey” water – where household wastewater from sinks, washing machines and dishwashers etc. is recycled and put to good use. Uses include water for laundry and toilet flushing. Treated greywater can also be used to irrigate both food and non-food producing plants. The nutrients in the greywater (such as phosphorus and nitrogen) provide an excellent food source for these plants.
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