Yes, in Australia there is very strict water allocation systems in place, significant surface water is allocated for food production (agricultural activities) in the Murray Darling Basin area (main food bowl region), however the water allocation follows a balance approach for beneficial water usages as follows (a) irrigation-major allocation (b) town supply (c) domestic use (d) environmental flows (environmental water for smooth functioning of ecosystems, in recent time government is buying water from irrigators to increase environmental flows) (f) others –Industry. Though there are annual (predetermined allocation based on the forecasted volume of water expected to be available) however, resources availability are monitored every fortnight and adjustments are made accordingly. There are major water savings programmes via improvement of irrigation infrastructure and modernization (improved metering, computer aided water supply, irrigation channel remediation (plastic and clay lining), pipelining, automatic regulator, upgrading dethridge wheel, reuse and recycle of water, rainwater harvesting.

Irrigation practices can lead to substantial saving in irrigation water. We have seen huge savings in irrigation water when shifting from gravity irrigation to center pivots (sprinkler irrigation). Also when the sprinkler were changes according to plant growth stages substantial amount of irrigation water was saved. I will can share that the irrigation requirements went down by 70 - 80%.

Yes, in Australia there is very strict water allocation systems in place, significant surface water is allocated for food production (agricultural activities) in the Murray Darling Basin area (main food bowl region), however the water allocation follows a balance approach for beneficial water usages as follows (a) irrigation-major allocation (b) town supply (c) domestic use (d) environmental flows (environmental water for smooth functioning of ecosystems, in recent time government is buying water from irrigators to increase environmental flows) (f) others –Industry. Though there are annual (predetermined allocation based on the forecasted volume of water expected to be available) however, resources availability are monitored every fortnight and adjustments are made accordingly. There are major water savings programmes via improvement of irrigation infrastructure and modernization (improved metering, computer aided water supply, irrigation channel remediation (plastic and clay lining), pipelining, automatic regulator, upgrading dethridge wheel, reuse and recycle of water, rainwater harvesting.

Golam I think this is how the water resources need to be allocated and managed. Most countries consider it as a free resource and apathy towards this precious resource is going to create an ecological imbalance in long term.

Well, I am afraid that the question is a bit unspecific. 25% is a lot and the development of potential water saving rates will depend pretty much on the current status of water use in irrigation as well as on the institutional and (socio-) economic context of the water users. In order to become a bit more specific by myself: The more low-level current irrigation approaches are, the more savings are possible through comparatively basic improvements in irrigation technologies&management. But the crucial issue is always the situation of the current water users. Do they have the means for required changes (potential for investments, reliability of water provider etc.)? What would be the impact of saving water on their livelihood (income, but not only , cash availability, household supply and uncertainity ("risk") are of equal importance)?

Other key issues are water quality and allocation. Are the potential savings from irrigation directly useable for domestic purposes or is treatment required? Is the required treatment competitive to other possibilities of water provision? Is additional water storage and transport required in order to get saved water to the households under water stress?

So that's just a (not complete) selection of issues to consider. It is difficult - and probably even impossible - to give a straightforward answer to your question, if the conditions of the given case are not known. However, I would dare to sign the following general statement: Water savings in the area of 25% will certainly imply significant economic and social impacts. A realistic chance for achievement will strongly depend on accompanying measures which alleviate the downside for those who have to save the water, enable them to install the required technological solutions and adapt the existing informal and formal institutions to the new set-up of the water sector. In brief: saving of 25% = technically probably possible, but realistically only achievable with a complex set of measures from a number of disciplines (definitely not only from technics or agronomics)

Hope that was helpful as a starter for further research

Very good conducive answer. thanks peter

Dear Dr. Saravanamuttu Subramaniam Sivakumar,

The usages are of different natures and complex to quantify.