water: planning for sustainability

The attention of the general public (as a group, not individuals) is generally focused on the present, but that should not be true of governance. One of the reasons for planning is to attempt to forecast issues and design around them, this is among other things the role of the town planners.

Water (as we all know) comes from the tap, and as long as it flows everyone ignores it. However it was (or so it seems to me) just a short while ago we were in the grip of a serious drought and water restrictions.

At that time (if you weren't yet living here) we experienced a drought where the normally regular summer high rainfalls failed to arrive. This resulted in a very worrying drop in the Hinze Dam levels to around 30% capacity:

As you can see from the data in the above chart the November 2001 through to Feb 2002 rains failed to arrive. Strangely this was regarded as the 2002 2003 drought (even though 2003 rainfalls were more or less normal). However people were (quite rightly) concerned about this as it was the first time that such a situation had occurred. Importantly though, it wasn't the first time such a weather pattern occurred.

Had we then had low rainfall for the 2007 year (I wrote my masters thesis on this in 2005~6) we would have been in a similar situation or perhaps worse. Looking at the last hundred and something years of data, we see rainfall in Southport and Springbrook (where the Hinze Dam catchment area is) like this:

Quite seasonal, and quite a significant amount of rain between Jan and April, but not much between June and Sept. The vertical bars on that graph represent the ranges of rainfalls, and the blue and green lines the average. You can see that 0 mm of rain in Jan Feb and Nov are not unheard of, so nix out climate change having an influence here ... Fundamentally this is about population growth, exceeding the carrying capacity of the existing paradigm and a lack of planning.

People started worrying and the Gold Coast City Council (amid a backdrop of hysterical media) succumbed to pressures and signed up to a pipeline to Logan to get some 35 Mega-liters of water per day from Logan to supplement the 180 Mega-liters per day being drawn from the Hinze (and to a lesser extent Little Nerang) Dam.

The GCCC responce also included an examination of alternatives which included the Coomera Pimpama Water futures plan. The Council was thinking in terms of Business As Usual (BAU) and obtaining more water (we always have to have more don't we) and began looking at alternatives like:

• getting more water from Wivenhoe (as if they have too much for Brisane's expanding thirst)
• pulling in more from a 'water pipeline'
• desalination (ask someone who lives in Tugun about that)
  

The council produced a number of documents suggesting that water demand would go up like this:



And offering suggestions on how to cope with this such as:

I however took a different point of view and thought that (basing my views on "Ecological Modernisation" concepts) that we could achieve more with less by moving into the modernisation process rather than just doing "Business as Usual"

As the population of the GC community is expanding, I undertook an examination of the water needs of the community via both the BAU method and looking at what could be done with a two pronged approach. 1) the inclusion of water efficiency in the home and 2) the suppliment of community water with rainwater tanks. Note that water efficiency is not just the simplistic (and unpalatable) "demand management" strategy where you use showers which produce an annoying mist or give people egg timers to suggest they have shorter showers.

I factored in a very modest 1% per annum reduction in community water requirement and I also added another "what if" situation of the rain water tanks. Factoring this in I came up with the following projection of water demand.




So, following the GCCC model of Business as Usual the water needs of the community grew exactly with the community population (as they projected) to nearly 480 Mega-liters a day, while the use of modernization principles to reduce water demands brought a growth to 250 Mega-liters per day but with a much slower peak. Adding in the water tanks with modernisation brought the overall use to a point lower than 2001 usage figures even with a population increase from 450,000 to over 1,100,000.

So there really is potential for the community here to cope with population growth via planning and modernisation.