Assessing the Effect of Unconventional Gas Exploitation on Cumulative Future Water Demands and Developing Potential Water Stress; A Scottish Perspective

One of the most discussed aspects of unconventional gas extraction process is the effect of hydraulic fracturing or “fracking” on local water resources. Recent research focuses only on water contamination (water quality) and has not considered water stress (water quantity), even when it is noted “the growth of unconventional gas extraction brings with it a heavy demand for water and that`s straining local water supplies, often in already drought-prone areas.”

Fracking is a water intensive industry; fracking fluid is 98% a sand-water mix and water consumptions of 3 million gallons per shale gas well, or around 44 billion gallons of water a year based on 2012 data are typical in the USA. Such a consumption is comparable to only one-week’s water demand for a golf course however such water needs “… still challenge supplies and infrastructure”. Indeed UK comparison indicates that a similar fracking water demand for Scotland could be as much as nearly three times the annual water requirement for the whisky industry (assessed as 16 billion gallons total water). Thus, the forecast programme of fracking is likely to place extra demands on existing Scottish water resources.

Recent water crises in South Africa and Australia highlight the effect water potential scarcity can have to disrupt water supply used for domestic, industrial, and agricultural purposes and lead to water stress. With a forecast change in UK climate (UKCIP 19) affecting future water resources, such extra industrial demands could develop water stress. UK shale resource areas all lie within, or close to, regions that are either prone to drought now, or are drought forecast in 50-70 year projections. If a similar US water demand model were employed in the UK, the growth of UK fracking could place additional stress on existing water resources and, potentially, increase local water stress.

This study evaluates these issues by creating a framework to analyse and map potential future water stress across Scotland. Relevant data on water demand and hydrological supply is combined with estimates of gas extraction process requirements to assess water stress consequences in line with the future Climate Change prediction scenarios (UKCIP09). The initial framework results for the Scottish water resource zones show water stress for each would increase significantly from 2018-2080 because of both the growing population and hydraulic fracturing demands. The study methodology and lessons learned can be readily developed for other regions water demand contexts.