Water Grids

The call for water grids is growing since they cut water depletion. The widespread drought is a wake up call. Lakes Michiganand Huron inUSAhit their lowest levels on record. InIllinois, the US Army Corps of Engineers has been dredging the Mississippiand blasting away rock formations on the riverbed in a bid to sustain the 3 – meter depth that barges need to transmit exports to the coast.

The mounting urban water demands have long clashed with the needs of agriculture and navigation, and climate change is expected to ratchet up the tension, causing wilder swings between drought and flood even in regions that may not get drier overall. Water shortages are only likely to intensify; setting states at one other’s throats.

TheUS’s water wars are being fought in the courtroom, rather than on the battlefield. Can science and technology come to the salvage in the form of smart water distribution and better modeling of supply and demand?

Engineering solutions are still being considered in some places. States will have to generate better estimates of future supply and demand and work out how to safeguard what nature provides.

Finding ways to save water is a top priority. New techniques must go beyond asking people to water their lawns less frequently and instead install smart delivery systems to cut water wastage.

There are immense opportunities to cut demand in agriculture. Irrigation could be turned off as soon as a field is fully watered. To do this a box is hidden halfway across the field. Sensors detect when it fills with water and send radio signal back to another unit that reins the water flow, allowing the same amount of water to be applied again before automatically shutting off. A study shows that the method reduces water use by about ten per cent. Water is untied through efficiency rather than dams or pipelines.

There is a need in working to prevent spillages in channels that move water around. Recently manual channel gates were replaced by mechanical ones that are opened remotely before water backs up and spills out. It has slashed its losses through spills from about 10 per cent to almost zero.

There is another mode to cut the wastage by giving building managers real-time information about their usage, using smart water meters with flow monitors.

Water use for cooling in power generation could also be targeted for cuts. By switching the regions’ power plants to air cooling could accumulate water.

All of these approaches and more may be needed to ward off shortages. The cheapest water is going to be the water which can be saved.