Red hot: water management and extreme heat

Last week, the Met Office issue extreme heat warnings across much of the country. The latest record temperatures follow what has been a significant stretch of hot, dry weather for much of the UK.

One of the hottest summers on record took place in 2018 – along with 1976, 2003 and 2006. It certainly looks from these records that extremes of heat are being experienced more frequently. By 2050 it is expected that such hot weather will become more likely, with the chance of a summer as hot as 2018 increasing from less than 10% to over 50%[i]. Along with the health risks of extreme heat, such high temperatures can cause heat-sensitive systems to fail, potentially leading to localised loss of power and other essential services, such as water.

Water is a precious resource – anyone farming will recognise this more than most. The ease with which we can access water – with a simple turn of the tap at our kitchen sink – means that for much of the British public water scarcity isn’t something that is thought about regularly, if at all. But increasingly it is our reality.

The water resources planning process, which looks at water demand to 2050, has calculated a 4,000m litre water supply deficit per day[ii] based on climate change, population growth and current consumption trends. Part of this needs to be met by users conserving water and using what we have available more efficiently.

It also requires investment in capture and storage so that we can use wet periods to build resilience for the dry, hot weather periods. The CLA published its Water Strategy last year. In it, the CLA calls for continued government grants for on farm reservoirs, funding to support private water supply resilience and for Defra, the Environment Agency and Natural Resources Wales to include water for crops and livestock as an essential use of water in the National Drought Plan.

Admittedly, rainwater harvesting isn’t much use when there isn’t any rain… but forward planning by capturing the water when it is there can help ease the pressure slightly when it isn’t. Check with your local water company to see if you can access grants for rainwater harvesting equipment in your local area. Keep an eye out for future rounds of the government’s Farming Transformation Fund which is currently offering grants for reservoirs.

Try to avoid watering gardens and irrigating crops at the hottest time of day when water more quickly evaporates. Watering when the sun goes down and the weather is cooler ensures irrigation can take place most efficiently. It also means that you avoid using water at times when demand from other users is highest.

As part of your estate wide water management plan, think about how you can work with neighbours to build resilience against drought. Work with neighbours to build resilience to dry weather by sharing and trading abstraction licensing quantities. Always ensure you are working within the abstraction limits and conditions as per the licence.

Wherever possible, avoid non-essential uses of water and prioritise the water required during the hot period. For example, don’t wash equipment down until temperatures start to reduce again.

Check for any leaks and fix them. According to the European Environment Agency, a dripping tap can waste as much as one litre of water per hour so even small drips and leaks are important to fix. If you can’t fix them, try and capture the water for use elsewhere. Regularly reading water meters can help to identify leaks.

Next time you need to buy a white good or other water using fixtures and fittings, check the water efficiency of the appliance. Under the 25 Year Environment Plan, the government has announced mandatory water labelling. For now you might have to seek out the information. Low flow valves can be a cheap way to improve the water efficiency of taps and shower heads.

Not strictly water saving, but important to consider for the hot weather: planting trees can help to create all important shade for livestock. Shade from trees can also be beneficial for aquatic animals; positioning trees along rivers can help lower water temperatures in summer and help fish to survive. With temperature extremes expected more frequently, it makes sense to plan ahead and think about adding trees or other structures for additional shade.