Water scarcity: a worldwide problem and vertical farming’s solution

Of the many benefits of vertical farming, for those of us growing in Scotland, the ability to reduce water usage compared with traditional growing has always been a ‘nice to have’, but perhaps one of the less important benefits..

Here in the north of Scotland, we are blessed with water that is both cheap and plentiful, (too plentiful sometimes, with many summers being a damp washout!)

At Vertegrow, we have always sought to reduce our water usage though and treat our water intake responsibly. Although arguably lower on the list of priorities, there is still an environmental footprint in mains water and rainwater is better for our plants. For this reason, we have always grown in harvested rainwater for the local benefits, whilst being mindful at the benefits this brings abroad.

Raindrops. Not something seen often in Summer 2022
Raindrops. Not something seen often in Summer 2022

The crops Vertegrow grows are herbs and leafy greens which are generally imported into the UK from abroad: from areas with the potential for water scarcity, particularly in a warming world.

The last few months have focussed our minds on this: in many parts of Europe and North Africa where our salad greens our grown, people are sweltering under high temperatures and low rainfall. The importance of growing crops in a way that does not put further pressure on the water supply and eco-systems has taken on new importance. Whilst spending time in Germany earlier this summer, I was struck by a visit to a waterfall in the Black Forest – normally a popular tourist spot, it was in fact a completely dry riverbed, with not a drop of water running. That fact was reflected in warnings that the Rhine might soon be too shallow for shipping and warnings in other sectors such as energy.

Whilst we have previously focussed on reducing shipping miles (and removing their associated carbon footprint), the need to grow crops locally to reduce water impact too, has therefore risen to the front of our minds.

As the summer has progressed, water scarcity and warnings of drought have crept closer. Hosepipe bans are in force in England and here in normally lush and green Scotland, talk of water scarcity started to emerge. The problem is now reaching the food chain as Scottish farmers are restricted from abstracting water from rivers for crops. Those huge sprinklers which many of us are used to seeing in rural Scotland on sunny days will fall silent over the coming days and there is a real risk of crops being destroyed as a result.

At Vertegrow, all of the water we use for growing crops is harvested from the roof of our building, stored in tanks and then used efficiently. Our cyclical watering system means that water is flooded through our growing crops and any unused water (which is not picked up by plant roots) returns to the holding tank for the next cycle. Water transpired from plants is also collected and returned to these tanks, all of which means that virtually the only water leaving our farm is in the crops themselves. Calculations by others have suggested that this efficiency means that vertical farming reduces water use in growing by up to 95% (compared with systems where water is inefficiently applied and not taken up by crops, causing run off or evaporation).

Thankfully we had the foresight to calculate the size of our rainwater holding tanks to endure a prolonged dry spell and so, as a result of the efficient design of our water system, our crops will grow happily over the coming weeks and months.

As this long, hot summer rolls on, the benefits of growing locally and sustainably are therefore being felt not just on the water systems around the world, but also more locally in Scotland.