Climate change

Even before our borehole ran dry we had noticed the weather here outside Insch was clearly different to what we’d expected. While we’ve had some cold days in the past two years when it’s gone down to -12C, we haven’t had that much snow or rain.

Now the North-east is reputed to be one of the drier parts of Scotland, but you’d still expect there to be a fair amount of rain and snow, especially as you move inland and uphill. Our neighbours have regaled us with tales of skiing to the shops, of snowblowers taking five hours to clear three miles of road, and over snow drifts over the eaves.

Similarly with the rain, we expected fairly prolonged spells of rain and sleet although not as much as wetter parts of Scotland. Instead, we find ourselves with long dry spells under a heavy overcast and when we do get rain, it can be extremely heavy and cause brief but intense flash floods.

So it was with some interest that I read the report from our hydro-geologist friend after he’d looked into our situation and the reasons behind the borehole running dry.

This is an edited extract of his report to us:

Unfortunately with climate change, whether you believe the reasons behind it or not, we are moving to less frequent and more intense rainfall events. This is bad news for people on private water supplies drawing water from locally important aquifers such as yours.
The trend towards higher intensity rainfall events tend to give rise to high runoff and less percolation into the land.
This is resulting in less recharge into these locally important aquifers and with the same or higher rates of abstraction rapidly reducing water levels. In your case the hydrographs (flow measuring) for your nearest river, the Urie, say it all.
The results for the past 20 years clearly show what is happening. Between 1986 and 1996 the average flow at Pitcaple was 15 cubic metres per second with no maximum flows ever exceeding 30 cubic metres per second.

From 1996 to 2006 the average flow fell and was interspersed by a series of intermittent flashy flows exceeded 30 cubic metres per second on 11 occasions (none in previous ten year!) and going as high as 60 cubic metres per second on a couple of occasions.

In addition, your smallholding would normally be expected to have 2-4 inches of snow on the surrounding hills at this time of year with this snowmelt also providing essential recharge to the groundwater and rivers. So far in 2006 there has been none.

Basically although we may be receiving the same overall annual total volume of rainwater little if any is finding its way into the locally important aquifers that rural communities so heavily depend.

As such rural Aberdeenshire is fast approaching a situation akin to rural Ethiopia with rapidly dwindling water supplies and people spending 2-4 hours a day finding water.

Has that got your attention? Then how about this from a member of the National Hydrological Monitoring Programme (who stressed that he would need more detailed information to be more conclusive):

The dryness of the 2004/05 winter is a likely to be an influential factor.

Rainfall figues available to me suggest that the infiltration during the winter before last would have beeen minimal - leading to very meagre spring flows in 2005 and, given the recent dryness, over this winter. It may be worth asking you neighbours about the winter of 1995/96 when soils also remained pretty dry through the winter.
I hope that the blocking anticyclonic conditions which has been a feature of the winter thus far, soon releases its grip on synoptic patterns and allows a string of Atlantic fronts to march across the UK. They would be as welcome down here as in your neck of the woods.

As to why the borehole did not run dry in 1995/96, that’s because of another factor - trees (of which, more later).

Still not convinced? Then the BBC News report Stark Warning Over Climate Change should make interesting reading.