UK groundwater use in the future

Groundwater use in the UK has changed dramatically over the past 200 years, and pressures related to demand for water, climate change and land use will lead to further change in the future. Water companies plan on a 25 year timescale. Their 2015 water resource management plans (WRMPs) looked ahead to 2040, and we show some of these projections in Figures 1–3. Water companies are also assessing future supplies and demand to 2065, as described in the WaterUK water resources long-term planning framework report.

Projections for reductions in groundwater availability by 2040

Sustainability reductions

Sustainability reductions by 2040

Some public supply water sources (surface water and groundwater) will have their abstraction licence limited in order to redress impacts that these abstractions have been having on the environment. These reductions may be intended to alleviate low river flows or water levels in wetland areas, usually in order to protect habitats.

The map of groundwater sustainability reductions (Figure 1) shows that some water company areas will have to make significant reductions to their existing groundwater abstractions. For example, three companies will have to reduce existing groundwater abstractions by over 10 per cent (Bristol Water, Southern Water and Affinity Water). In some cases, companies will be able to replace reductions with increased or new groundwater abstractions elsewhere in their supply areas. If not, they will need to look at other supply or demand management options to ensure they can continue to meet demand.

Climate change impact

Climate change impacts by 2040

As part of the water resources management planning process, water companies were also required to estimate the effect that climate change might have on the availability of water in their supply areas. These impacts are a combination of the predicted effect of climate change on groundwater levels, plus the resilience of the water supply system to climate change, such as borehole depths and pump intake depths.

Our plot of estimated climate change impacts on groundwater deployable output (DO) (Figure 2) suggests that the models used calculate that relatively small impacts (zero across more than half of England, and less than five per cent across the rest of England and Wales) are expected. Again, companies have had to consider supply or demand management options to ensure they can continue to meet demand given these likely future reductions in supply from existing sources.

Combined impact

Combined sustainability reductions and climate change impacts by 2040

We have looked at the impacts of planned sustainability reductions and climate change impacts as a proportion of the groundwater deployable output (DO) in 2015 (Figure 3). The most impacted areas are those where larger sustainability reductions have been agreed.

Notes on these figures

These figures show the projected percentage change in groundwater availability by 2040, however, these should be considered alongside the figure showing groundwater as a percentage of deployable output, 2015. Some areas where groundwater is only a minor component of deployable output show a relatively large proportional projected change to groundwater availability, but the actual volumetric change would be small compared to areas in which groundwater is a large percentage of total DO. Northumberland Water is a notable example: they project the greatest climate change impact proportionately, but as groundwater only forms about four per cent of their total deployable output, the actual volumes involved are not huge.

Better quantification of climate change impacts

The BGS is undertaking research, such as developing the SPIDDER radial flow model, to improve methodologies to quantify climate change impacts on groundwater levels and borehole yields.

New groundwater resource schemes

New groundwater resources planned by 2040

Plans for new groundwater schemes are shown in Figure 4. For example, Bristol Water will have a 10 to 20 per cent reduction in groundwater DO due to sustainability reductions (Figure 1) and up to five per cent resulting from climate change (Figure 2), but are not planning to replace these with any alternative groundwater resources (Figure 4).

BGS research on groundwater and environmental change

At BGS we are researching the impacts of environmental change, including climate change, on groundwater in the UK and internationally. Our research includes:

  • reconstruction of historic groundwater levels
  • modelling future climate change impacts on groundwater resources and quality
  • assessing resilience of groundwater in Africa to environmental change

Contact

Please contact Matthew Ascott for further information.