Industry, Domestic and Agriculture Water Conservation Strategies:

·  Redesigning manufacturing processes

·  Replacing green lawns in arid and semiarid regions with vegetation adapted to a dry climate (xeriscaping)

·  Using drip irrigation to water gardens and other vegetation around homes and businesses

·  Using water meters to monitor and charge for municipal water use

·  Having ordinances requiring water conservation in water-short cities

·  Requiring or encouraging use of water-saving toilets and showerheads

·  Using washing machines that load from the front instead of the top, such machines use 40 - 75% less water

·  Reusing gray water from bathtubs, showers, bathroom sinks, and clothes washers for irrigating lawns and non - edible plants

·  Installing or leasing systems that purify and completely recycle wastewater from houses, apartments or office buildings

·  Collecting and using rainwater for flushing toilets, irrigating gardens, watering lawns, and putting out fires

·  Reducing personal water use and waste

Industry

·        Alternative water sources – a number of industrial and commercial water uses do not require water of potable quality (i.e. Certain cleaning processes, rinsing, cooling, heating, and irrigation applications.)

·        Upgrade heating and cooling equipment

·        Plumbing fixtures – low volume toilets, urinals, showerheads and faucets

·        Adjusting blow-down cycles in cooling equipment and recycling process water

·        Closed-loop cooling system

·        Sweeping floors before being washed down

·        Potable high-pressure pumps- can lower cleaning use by 40%

·        Hoses-automatic shut-off valve with a reduced flow nozzle

·        Automatic car washes – re-use of wash-water [non-recycled water may still be needed for the final rinse]

·         Hands-free / foot-activated peddles on faucets

A case study in industrial water reduction: http://www.state.ma.us/ota/cases/hitech.htm

Agriculture

         Methods for reducing water waste in irrigation:

· Lining canals bringing water to irrigation ditches

· Leveling fields with lasers

· Irrigating at night to reduce evaporation

· Using soil and satellite sensors and computer systems to monitor soil    moisture and add water only when necessary

· Polyculture

· Organic farming

· Growing water efficient crops using drought-resistant and salt tolerant crop varieties

· Irrigating with treated urban waste water

· Importing water intensive crops and meat

         How We Can Use Less Water in Irrigation:

What is drip irrigation?

It is inexpensive, weather resistant, flexible plastic tubing that consists of a network of perforated plastic tubing, installed at or below the ground surface. The small holes or emitters in the tubing deliver drops of water at a slow and steady rate close to plant roots.

·  Center-point low-pressure sprinklers - allow 80% of the water input to reach crops and reduce water use over conventional gravity flows by 25%

·  Low-energy precision application (LEPA) sprinklers - allows 90 - 95% of the water input to reach crops by spraying it closer to the ground and in larger droplets than the center-pivot, low-pressure system. LEPA sprinklers use 20 - 30% less energy than low-pressure sprinklers and typically use 37% less water than conventional gravity flow systems.

·  Using surge or time-controlled valves on conventional gravity flow irrigation systems send water down irrigation ditches in pulses instead of a continuous stream.

·  Using soil moisture detectors to water crops only when they need it

·  Drip irrigation systems can raise water efficiency to 90 - 95% and reduce water use by 37-70%.

What are the advantages of drip irrigation systems?

· Flexibility to conform to patterns of crops and can be easily relocated

· Efficiency, with 90 - 95% of the water input reaching crops

· Lower operating costs because 37 - 70% less energy is needed to pump this water at low pressure and less labor is needed to move sprinkler systems

· Ability to apply fertilizer solutions in precise amounts, which reduces fertilizer use and waste, salinization, and water pollution from fertilizer runoff

· An increase in crop yields to 20 - 90% by getting more crop growth per drop.

· Healthier plants and higher yields because plants are neither under watered nor over watered

       Domestic

           Rainwater Catchments Systems for Domestic Supply:

Different types of rainwater catchment systems are applicable for either urban or rural settings. The main focus here is on rural supply for small farms, villages and households.

Basic types and features of rainwater catchment systems are:

   -  a catchment surface where the rainwater runoff is collected

    - a storage reservoir where the rainwater is stored until required

    - a delivery system for transporting the water from the catchment to the storage reservoir, e.g. gutters      and drains

               Examples from Australia:

·   Roaded catchment: is a series of parallel cambered ‘roadways’ that are prepared and linked through a network of drainage ditches and channels, which divert runoff into an excavated open reservoir. By smoothing out the land depression storage, evaporation and infiltration losses are reduced by water quickly flowing into storage tanks. Compacting the surface or first covering it with a layer of clay can further decrease infiltration losses. (Not recommended in areas with sandy soil). Water treatment is required.

Catchments sizes typically range from less than two to over 40 hectares. In areas with rainfall of 300-400mm, the proportion that can be harvested varies from between about 25 and 40 per cent.

Several thousand of these systems have been constructed, especially in Western Australia where they are common on commercial farms for stock watering. Experimental systems have also been replicated in Texas and Arizona.

·   Flat batter dam: circular or square catchments are graded to slope at 1-2° towards a central reservoir, the excavation of which provides clay that is spread to a depth of 0.1m over the catchment, yielding runoff efficiencies of up to 40 per cent. Water treatment is required.

·   Roof catchment systems: rainfall is collected from rooftops and funneled into storage tanks. Depending on the size of the building and level of water use, this system gives users the option of determining the demand rate and level of system reliability that best suits their needs. The benefits of soft rainwater for washing hair and clothes are mentioned; however, health & safety standards associated with rainwater supplies still need to be measured to ensure that it is kept safe to drink.

               Examples from New Zealand:

·   On many small peninsulas and offshore islands, most residents depend on roof water for their potable supply. In a large number of New Zealand’s numerous national and regional parks and forest reserves, many overnight huts and rest facilities rely on roof tanks, e.g. Nelson lakes National Park.

·   Technical advice and information regarding the design, implementation and maintenance of water quality in domestic rainwater systems, although available from some district councils, is not as accessible or detailed as in Australia.

                Examples from China:

·   Rainwater tanks - bottle-shaped underground tanks have traditionally supplied an eight-month supply of water to one family during the dry season and would suffice for up to 10 months of drought if stricter rationing was applied. Tile catchments, concrete-lined courtyards, cement channels and upgraded cement-lined water cellars have been developed, demonstrated, and piloted, and were being widely replicated.

                Examples from Germany: rainwater collection in an urban setting

·   Rainwater catchment systems for non-potable supply uses such as garden watering, toilet flushing and use in washing machines. Household rainwater systems are used in combination with seepage wells. Results of this decrease pressure on storm water drains, sewers and water-treatment plants, reducing flood risks and recharging the groundwater.

        Conservation Incentives:

  ● Alternative to developing expensive groundwater containment

  ● Higher self-reliance in water, energy and food supplies

  ● Sustainable lifestyle

 Links:

UNDP - World Bank Water and Sanitation Program:

www.wsp.org

WEDC - Water, Engineering and Development Centre:                                                      

 http://www.lboro.ac.uk/departments/cv/wedc/specialist-activities/ws/research/index.htm

CSE - Center for Science and Environment: Rainwater Harvesting:

http://www.rainwaterharvesting.org

References:

Miller, Tyler G. 2002. Living In The Environment - Principles, Connections, and Solutions.12th Edition. WaterPlow Press. Amherst, MA.

Gould, John &n  Nissen-Pertersen, Erik. 1999. Rainwater Catchment Systems for Domestic Supply, Design,         Construction and Implementation. Intermediate Technology Publications Ltd. London, UK.