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Thursday, December 11, 2008

Water conservation,Agriculture,Water Efficiency

Water conservation refers to reducing the use of water.

The goals of water conservation efforts include:

* Sustainability - To ensure availability for future generations, the withdrawal of fresh water from an ecosystem should not exceed its natural replacement rate.
* Energy conservation - Water pumping, delivery, and wastewater treatment facilities consume a significant amount of energy. In some regions of the world (for example, California ).
* Habitat conservation - Minimizing human water use helps to preserve fresh water habitats for local wildlife and migrating waterfowl, as well as reducing the need to build new dams and other water diversion infrastructure.


Water-saving technology for the home includes:

* Low-flow shower heads (sometimes called energy-efficient shower heads as they also use less energy, due to less water being heated).[citation needed]
* Low-flush toilets, composting toilets and waterless urinals, which can have a dramatic impact in the developed world, as conventional Western toilets use large volumes of water.
* Faucet aerators, which break water flow into fine droplets to maintain "wetting effectiveness" while using less water. As a bonus, they reduce splashing while washing hands and dishes.
* Wastewater reuse or recycling systems, allowing:
o Reuse of graywater for flushing toilets or for the garden, and
o Recycling of wastewater through purification at a water treatment plant. See also Wastewater - Reuse
* Waterless car wash
* Rainwater harvesting


For crop irrigation, optimal water efficiency means minimizing losses due to evaporation or runoff. An Evaporation pan can be used to determine how much water is required to irrigate the land. Flood irrigation, the oldest and most common type, is often very uneven in distribution, as parts of a field may receive excess water in order to deliver sufficient quantities to other parts. Overhead irrigation, using center-pivot or lateral-moving sprinklers, gives a much more equal and controlled distribution pattern, but in extremely dry conditions, much of the water may evaporate before it reaches the ground. Drip irrigation is the most expensive and least-used type, but offers the best results in delivering water to plant roots with minimal losses.

As changing irrigation systems can be a costly undertaking, conservation efforts often concentrate on maximizing the efficiency of the existing system. This may include chiseling compacted soils, creating furrow dikes to prevent runoff, and using soil moisture and rainfall sensors to optimize irrigation schedules.

* Recharge pits, which capture rainwater and runoff and use it to recharge ground water supplies. This helps in the formation of ground water wells etc. and eventually reduces soil erosion caused due to running water.

1. any beneficial reduction in water loss, waste, or use;
2. a reduction in water use accomplished by implementation of water conservation or water efficiency measures; or,
3. improved water management practices that reduce or enhance the beneficial use of water. A water conservation measure is an action, behavioral change, device, technology, or improved design or process implemented to reduce water loss, waste, or use. Water efficiency is a tool of water conservation. That results in more efficient water use and thus reduces water demand. The value and cost-effectiveness of a water efficiency measure must be evaluated in relation to its effects on the use and cost of other natural resources (e.g. energy or chemicals).

Water Efficiency

Water efficiency can be defined as the accomplishment of a function, task, process, or result with the minimal amount of water feasible, or an indicator of the relationships between the amount of water needed for a specific purpose and the amount of water used, occupied or delivered.

Minimum Water Network Target and Design

The Cost effective minimum water network is a holistic framework/guide for water conservation that helps in determining the minimum amount of freshwater and wastewater target for an industrial or urban system based on the water management hierarchy i.e. it considers all conceivable methods to save water. The technique ensure that the designer desired payback period is satisfied using Systematic Hierarchical Approach for Resilient Process Screening (SHARPS) technique.

Another established technique for maximum water recovery is the water pinch analysis technique. However, this technique only focuses on maximizing freshwater and wastewater reduction via reuse and regeneration.

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