A Decade of Water Data
I have not been dutifully keeping track of our water usage, but happily in this day and age it doesn't take long to bring most of it together.
It would be fair to say the data trends are not as clear as I would like, but they mostly make sense.
We first moved into our house at the start of the 2009/2010 financial year. That's the bright blue line, which starts very high but quickly drops as we begin making improvements. Eg: new more efficient shower head. 2010/11 remains at a similar lower level, with another big drop at the beginning of the 2011/2012 year. This was when we replaced the old toilet downstairs and plumbed in the 2 rainwater tanks to it and the laundry.
It should now be noted that this period, from around when we moved in to the winter of 2012 was a quite wet period in the local climate. 2011 recorded twice as much annual rainfall as we've had for most of the last six years. October 2010 was the wettest October on record for the Mitcham station, with nearly 145mm of rain.
This means full water tanks, less watering needed in the garden, and probably less bicycle riding - which usually means one less shower a day when David doesn't cycle. Despite all that, I'm still not sure why that one was the lowest usage period we ever had. It bounces back up a bit and then stays there for a couple of years, with no obvious spike to mark the arrival of bub1 in early 2012.
Mid 2015 sees the next big water bill. Bub2 has joined us, Bub1 is toilet training, and we have the bathroom renovation happening which means I'm using the old inefficient shower head upstairs instead of my usual one. 2015 is also the driest year in the time we have been here, less than 550mm total for the year (4.4mm in October).
While the following years are not so bad, continuing dry weather means more garden watering, more cycling-related showers, and of course we are now a family of 4, so the typical usage level creeps further up and is now above where we were in the latter parts of our first year here.
In the last couple of years we have had particularly high usage in the latter half of the summer. I think in 2019 this is at least partly because the pump on one of the water tanks stopped working for some unknown amount of time before I noticed and got around to replacing it.
This partly explains why usage suddenly dropped to the lowest point since 2012 in the following quarter. However the other significant factor there was that David was overseas for about 3 weeks. 3 weeks without using the upstairs shower apparently accounted for around 30% of our usage.
I have no explanation for 2018 though, and although not in this graph, the 19/20 financial year was tracking over 600L/day until Jan/Feb were the wettest they've been for quite a while, then the Covid-19 lock-down began. Since then, with David working from home and taking post-cycle showers less frequently, usage has dropped back closer to 2016 levels (despite the tank pump breaking again). So, I'm blaming his shower.
We are encouraged to aim for no more than 155L per person, per day. Technically if we stay below 620 for 4 people we meet that, but it irks me that we can't do better.
[19/20 year is not in the graph because I only just found the bills and couldn't be bothered redoing the graphs.]
Usage by year:
Usage by quarter:
Water Bills:
It would be fair to say the data trends are not as clear as I would like, but they mostly make sense.
We first moved into our house at the start of the 2009/2010 financial year. That's the bright blue line, which starts very high but quickly drops as we begin making improvements. Eg: new more efficient shower head. 2010/11 remains at a similar lower level, with another big drop at the beginning of the 2011/2012 year. This was when we replaced the old toilet downstairs and plumbed in the 2 rainwater tanks to it and the laundry.
It should now be noted that this period, from around when we moved in to the winter of 2012 was a quite wet period in the local climate. 2011 recorded twice as much annual rainfall as we've had for most of the last six years. October 2010 was the wettest October on record for the Mitcham station, with nearly 145mm of rain.
This means full water tanks, less watering needed in the garden, and probably less bicycle riding - which usually means one less shower a day when David doesn't cycle. Despite all that, I'm still not sure why that one was the lowest usage period we ever had. It bounces back up a bit and then stays there for a couple of years, with no obvious spike to mark the arrival of bub1 in early 2012.
Mid 2015 sees the next big water bill. Bub2 has joined us, Bub1 is toilet training, and we have the bathroom renovation happening which means I'm using the old inefficient shower head upstairs instead of my usual one. 2015 is also the driest year in the time we have been here, less than 550mm total for the year (4.4mm in October).
While the following years are not so bad, continuing dry weather means more garden watering, more cycling-related showers, and of course we are now a family of 4, so the typical usage level creeps further up and is now above where we were in the latter parts of our first year here.
In the last couple of years we have had particularly high usage in the latter half of the summer. I think in 2019 this is at least partly because the pump on one of the water tanks stopped working for some unknown amount of time before I noticed and got around to replacing it.
This partly explains why usage suddenly dropped to the lowest point since 2012 in the following quarter. However the other significant factor there was that David was overseas for about 3 weeks. 3 weeks without using the upstairs shower apparently accounted for around 30% of our usage.
I have no explanation for 2018 though, and although not in this graph, the 19/20 financial year was tracking over 600L/day until Jan/Feb were the wettest they've been for quite a while, then the Covid-19 lock-down began. Since then, with David working from home and taking post-cycle showers less frequently, usage has dropped back closer to 2016 levels (despite the tank pump breaking again). So, I'm blaming his shower.
We are encouraged to aim for no more than 155L per person, per day. Technically if we stay below 620 for 4 people we meet that, but it irks me that we can't do better.
[19/20 year is not in the graph because I only just found the bills and couldn't be bothered redoing the graphs.]
Usage by year:
Usage by quarter:
Water Bills:
