Water Conservation: Methods to Reduce Water Intake2024-06-24T12:37:04+01:00

WATER CONSERVATION: Methods to Reduce Water Intake

Saving water has never been more important in the UK. The Met Office predict that by 2070 the UK’s summers will be 1-6°C warmer and up to 60% drier (1). Additionally, the Environment Agency declared that the UK will not be able to meet demands for water in 25 years, with climate change and population growth both being factors for this conclusion. With the average person in the UK using 142 litres of water a day the government has introduced a target to reduce public water supply by 20% per person by 2038, in an attempt to limit household consumption to around 110 litres per person per day by 2050 (2,3). Improving water use efficiency in gardens is a great way to reach this goal – a priority for eco landscaping.

Recycled Water

– Collecting rainwater is one way to reduce water intake. This can be done by diverting water from drainage systems into a water butt or even a wheelie bin (4). More advanced measures like rainwater harvesting involve sinking tanks into the ground for use in the garden or other domestic tasks (5).

– Water can be reused from baths, showers, boiling foods etc. These grey waters can save a lot of water, but some may hold chemicals that are too strong for plants, weaker chemicals such as household soaps and detergents are harmless to plants (4).

– Grey water shouldn’t be stored as if left can cause harmful organisms to grow, also chemical shouldn’t be used on edible produce (4).

Drought Resistance

– Specific plants are also drought resistant, meaning they had adapted to resist the heat and lack of water for a longer period. These plants will not need to be watered as much as other species of plants (6).

– Examples of great drought resistant plants are glossy abelia (abelia x grandiflora), trumpet vine (campsis radicans) and white wild indigo (baptisia alba) (14).

– An alternative is to encourage native plant species in unused parts of the garden, as these plants are used to the climate and precipitation rates in the UK such as buttercups and ox-eye daisies.

– To improve your gardens resistance to drought, cultivate the soil deeply and add large quantities of organic matter, like composted bark, to improve the soil structure and its water retention (7).

– Studies have found that water absorbing geocomposite (WAG) which is an anthropogenic soil amendment (water retention granules), is one of the most efficient ways to maintain water retention in soil. Particularly in warm temperatures (30 °C) WAG was proved to on average keep the most water compared to other soil amendments tested (12).

– WAGs are made of a geotextile mesh pouch which is then filled with a superabsorbent polymer, Aquasorb 3005 KL (SNF Floerger, Andrézieux, France), to act as the water retainer in the WAG. Aquasorb 3005 KL is a synthetic anionic polyacrylamide polymer which does degrade naturally in soils at around 10% per year (17).

Plant and Soil

– Plants should be watered when they show signs of wilting, this can save water but also ensure they have a healthy root system (8).

– Weeding regularly can be an effective way of saving water (8) as it ensures that water is not being wasted on an undesirable plant.

– A brown lawn may not need watering, and it should recover when it next rains (8).

– Plants should be watered in the early mornings or in the evenings when it is cooler, and less evaporation will occur (9).

– Soil health is also key to water retention, and healthy soil with organic matter can retain water for longer, reducing the need to water as often (7).

– Mulching soil areas by plants can also reduce water loss as it increases infiltration (ability of water to go into the soil) and prolongs soil moisture by acting as a barrier to evaporation (10).

Watering Equipment and Garden Infrastructure

– Water retaining gels or granulates can also be purchased to stop water wastage, especially in hanging baskets(11).

– Most gels are made from cross linked polyacrylamide which is water absorbent but not soluble, with evidence suggesting that they don’t have a negative effect on soil health (15).

– Cellulose-based superabsorbent hydrogels which are completely biodegradable and biocompatible are being researched as a more environmentally conscious option. And have been found to increase soil moisture capacity by up to 400% (16).

– Sprinklers and hoses can both waste a lot of water and should be replaced with seep hoses, which are a more precise and use less water (9).

– Irrigation systems are useful but should only be used if absolutely necessary as plants can become dependent on them, instead opt for more drought tolerant plants.

– A watering cans are a direct way to target water to where it’s needed unlike a sprinkler and is more efficient than a hose (8).

– Permeable pavements ensure that water will not run off as waste but they can also reduce rainfall getting to the soil which may causes problems with subsidence especially with clays (13).

Sources

  1. https://www.metoffice.gov.uk/weather/climate-change/effects-of-climate-change
  2. https://www.water.org.uk/news-views-publications/news/vast-majority-brits-have-no-idea-how-much-water-they-use-each-day
  3. https://www.water.org.uk/water-supply/saving-water
  4. https://www.rhs.org.uk/garden-jobs/water-collecting-storing-and-using
  5. https://ukrma.org/about-water-re-use/rainwater-harvesting/
  6. https://www.ewburrownursery.co.uk/blog/How-%20often-should-you-water-trees-and-shrubs-and-what-about-drought-tolerant-plants222#
  7. https://www.rhs.org.uk/garden-design/drought-resistant-gardening
  8. https://www.nidirect.gov.uk/articles/saving-water-garden
  9. https://www.rhs.org.uk/garden-jobs/watering
  10. https://www.permaculture.org.uk/practical-solutions/mulching
  11. https://www.rhs.org.uk/soil-composts-mulches/water-retaining-granules
  12. Śpitalniak, M., Bogacz, A. and Zięba, Z. (2021). The Assessment of Water Retention Efficiency of Different Soil Amendments in Comparison to Water Absorbing Geocomposite. Materials, [online] 14(21), p.6658. doi:https://doi.org/10.3390/ma14216658.
  13. https://www.rhs.org.uk/garden-design/permeable-paving
  14. https://www.rhs.org.uk/plants/for-places/drought-resistant
  15. Sojka, R.E., Bjorneberg, D.L., Entry, J.A., Lentz, R.D. and Orts, W.J. (2007). Polyacrylamide in Agriculture and Environmental Land Management. Advances in Agronomy, [online] 92, pp.75–162. doi:https://doi.org/10.1016/s0065-2113(04)92002-0.
  16. Montesano, F.F., Parente, A., Santamaria, P., Sannino, A. and Serio, F. (2015). Biodegradable Superabsorbent Hydrogel IncreasesWater Retention Properties of Growing Media and Plant Growth. Agriculture and Agricultural Science Procedia, [online] 4, pp.451–458. doi:https://doi.org/10.1016/j.aaspro.2015.03.052.
  17. https://www.snf.co.za/wp-content/uploads/2017/08/Aquasorb.pdf