Digging deep to find vital water
Digging a hole in the ground in Christchurch can help save the world, as Nick Dudley Ward explains.
Ask anyone who experienced the Canterbury earthquakes what the most important component of an emergency kit should be and they will probably reply ‘‘water’’.
Several weeks ago, Australasia’s first global humanitarian engineering students literally dug deep as part of their studies, tapping into a disused water well in Ilam Fields on the University of Canterbury (UC) campus as part of a hypothetical post-disaster scenario in which the local water supply was knocked out.
As Cantabrians are all too aware, this scenario is a far from hypothetical one.
The aim of the exercise, in which students successfully pumped potable water, was to give them hands-on experience of responding to a disaster scenario and equip them with practical problem-solving skills to respond to basic humanitarian needs.
Teaching Australasia’s first engineering diploma of this type is something of a step into the unknown. However, our academic community’s collective experience following the earthquakes of 2010-11 means we are uniquely placed to build a programme in humanitarian engineering that plays to our distinctive Kiwi strengths.
A huge amount of planning went into the exercise. Students had to carry out essential tasks, including assembling the appropriate field gear, building relationships with Christchurch engineering firms, which were keen to help by providing advice and, most importantly, ensuring operational safety.
The students had to secure a safe drinking-water source on campus. They had a full-on day, setting up the response location, assembling the field gear and providing an emergency water supply.
They got far more than they bargained for because, on retrieving the pump, it got stuck in the well 15 metres below the surface. It took several hours and various attempts at applying Kiwi ingenuity (an application of Newton’s third law of motion – for every force there is an equal and opposite force – finally won the day) to finally dislodge the pump, resulting in several thousand dollars of damaged gear but a pump intact.
It was inspiring to see the students’ resolve and calmness in getting the job done. I had rather hoped for some failure, since it is through failure that we learn, although I didn’t anticipate what actually happened. But that is the nature of field engineering.
During the exercise I have to admit to having spent a moment reflecting on my diminished reputation come Monday morning when I would have suffered the ignominy of a stuck pump in a rather public location on the Ilam Fields.
In a broader context, groundwater poses particular challenges for the humanitarian engineer in both emergency response and development, compared to surface water. On one hand, it is a vastly more mysterious and, in my view, most fragile natural resource (the recent experience in Havelock is a poignant reminder of this).
In simple terms, you’re not sure what you’re going to get – what quality – nor how much you should take. Take too much and you won’t get it back.
It is perhaps surprising to learn that we have quite poorly resolved knowledge of Canterbury’s aquifers; all we can be certain of is they are complex. We are some way off developing a technology that will reduce this vital knowledge gap.
The same challenges are magnified in developing countries like Cambodia and Tanzania, where groundwater is often seen as a panacea, with rudimentary techniques for locating, drilling and pumping. Cambodia, for example, has 270,000 tube wells providing water for rural communities.
On the other hand, one has the physical problem of abstraction. One pump will not do for all wells – this depends on the physical characteristics of the aquifer and well, as well as the mechanical characteristics of the pump. This makes for a nice exercise in practical engineering: compromise and optimisation.
All in all this makes groundwater a fascinating resource, and one that may prove vital when we are confronted with the next catastrophic event. We do well to increase our emergencyresponse capability in this area.
On balance, the exercise was an extraordinary experience for me, for the students who participated and the staff who witnessed it.
It confirmed again our ability to work together as a community and it highlighted the mettle, resourcefulness and enthusiasm of our students. This will ultimately see them go forth and make the world a better place for us all.
Dr Nick Dudley Ward is director of studies for the Diploma in Global Humanitarian Engineering at the University of Canterbury.