News Source: LinkedIn Pulse Blog by Peter Brabeck Letmathe
Despite limited availability of freshwater for human use (in the right form, at the right place and at the right time – availability estimated at a worldwide total of 4,200 cubic kilometres), withdrawals continue to increase globally (not in the US, I will come back to this with a later post) and will probably reach an estimated 5,000 cubic kilometres this year. In a situation of secular overuse, drought turns into a much more severe crisis.
By 2030, without a substantial improvement in water management, this figure could be close to 7,000 cubic kilometres – an increase driven by growth in population and prosperity. If we want to avoid a much more severe water crisis in future, we will have to find ways to reduce freshwater withdrawals by 40% compared to this status quo extrapolation.
A 40% reduction within the next 15 years seems like a lot, but it is not impossible. In several posts here on LinkedIn, particularly those about the 2030 Water Resources Group that I am chairing, I pointed to ways that would significantly and cost-effectively contribute to narrowing the gap between withdrawals and sustainable supply of freshwater.
Measurement of withdrawals – the first step
Measurement would be an important first step: if you want to save water, you must measure its consumption in each sector of usage. If you can’t measure it, you can’t manage it.
In many if not most countries, we have to start in agriculture, which accounts for about 70% of all freshwater withdrawals worldwide, and more than 90% of water consumption (in California, according to US government data, it is 80% of all freshwater withdrawals).
But in too many instances, measurements of withdrawals remain incomplete, often with virtually no measurement of withdrawals by farmers (and often also a lack of measurement elsewhere, e.g. water withdrawals of municipal water supply schemes, to compare with delivery for estimates of leakage), and no measurement of actual needs – just rough global estimates, which indicate that withdrawals of freshwater by agriculture exceed the actual physiological need of plants by 100-150%. Fields are flooded, sprinklers run at noon, pumps continue when energy is free and the way out to the field is too long to bother about the water overuse; all entirely rational behaviours when water is not given any value at all.
Technologies to monitor and steer efficient use of water exist and function
Actually, the technologies to monitor, measure and steer efficient use of water exist – and they function. A good example are air and soil moisture sensors in a wireless network controlling drip irrigation I’ve seen being used in South Australia (my readers no doubt know many other comparable stories).
The first thing being measured is the humidity of the air, to adapt the water flow exactly to the evapotranspiration needs of the plant (or to stop the irrigation if the air is for some time too dry and most of it would not enter the soil). You will see these simplified weather stations all over the fields and vineyards.
Second, special devices in the soil measure how far down the irrigation water is actually seeping, i.e., as far down as the roots go, but not beyond. This optimises the water supply, and it protects the groundwater, since the irrigation water is ususally already supplemented with fertilisers.
At the heart of all this: no longer a nice farmhouse and barn we know from Europe and children’s books, but a computerised control centre, based on real-time data, which steers irrigation and the addition of fertilisers according to the exact need in different parts of the farm and different points in time.
Set incentives for comprehensive, cost effective solutions to water overuse
As an incentive to invest in such sophisticated schemes, and in order to make measurement and management fully relevant, water needs a value. Not surprisingly, in South Australia this is the case. Its value is set in a market of water usage rights tradable among farmers (i.e., giving a value does not mean imposing a tax on water use paid to government). And, as a result, it is carefully and smartly managed, contrary to many other places where it is seen, overused and abused as a free good.
Giving water a value will also work as a strong incentive for more water efficiency in industry, the generation of energy, and, last but not least, for reducing leakage losses in municipal water supply.
I know there are a number of innovations going even further; this is only the beginning of smart water management. An increasing number of companies offer highly innovative technologies and concepts; companies from the water sector (irrigation, treatment, supply, etc.) but also from other sectors (such as IBM, Dow and Ecolab for instance).
We need comprehensive, cost effective solutions to water overuse; piecemeal approaches and witch hunts will not do. Proper sensoring will be the first step.
Your comments, in particular with more information about innovations in measurement for better management of water, would be welcome.
Source: LinkedIn Pulse Blogs (2716 views, 670 likes, 106 comments)