brainbaking/content/post/2022/02/water-usage-and-prices.md

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Water Usage and Prices 2022-02-12T10:01:00+01:00
braindump
Hasselt
datavis

After plotting the natural gas prices of each quarter the last five years, it was only logical to expect a future post of other utilities such as water. As expected, the trend line is going up, but luckily, not as badly as the gas prices. We've been steadily paying more and more for our yearly water bills, but unlike the natural gas plot (see link above), we've apparently also been using more and more water.

Let's first take a look at another graph (blue, dotted: actual usage in cubic meters divided by ten; green, slashed: absolute total amount to pay yearly, divided by hundred; red, solid: unit price of water consumption on the bill):

I lack the proper numbers for year 2018, which explains the flat line between 2017 and 2018. It is not too clear from the graph, but the raw unit price of water in 2015 was €1.2066, and in 2020 €1.8364. That's an increase of more than 51% over five years, which is by itself quite stunning!

The total amount to pay line is hard to compare to the raw unit price. It takes our usage into account, which is clearly rising (41 cubic meters in 2015, 52 in 2020), and local taxes and reductions that I didn't include. Taxes are also increasing, but a lot less dramatically---between ten and fifteen percent. Getting a clear overview on the whole calculation and all the numbers is quite difficult.

What worries me is the blue (dotted) line going up. It could mean a lot of things. I can make a few statements that might or might not explain the trend:

  • The obvious one: since March 2020, everybody's working from home, including too much toilet flushes. But the numbers of 2021 aren't even in there yet.
  • My wife has been home on and off since 2017 thanks to a severe burnout. Even though our effective gas usage has only gone down, the water usage has gone up. Whether we're home or not, we tend to not turn on the central heating too much. But of course, we do consume more water when we're home.
  • We've been taking baths to relax more often. According to Engie, "toilets and baths/showers take 67% of our water usage into account".
  • Do we have a leak? It might not be a bad idea to take a good look at the counter before we go to bed and after we get up. Unless the dog manages to open the tap, it shouldn't have moved. I've never checked that before. Should I?

Here's the raw data, in case you'd like to compile your own graph:

years = [2015, 2016, 2017, 2018, 2019, 2020]		# jaar
usage = [4.1, 4.6, 3.9, 4.4, 4.7, 5.2]  			# cuub * 10
price = [1.95, 2.37, 2.12, 2.12, 2.61, 2.83] 			# eur total * 100
unit = [1.2066, 1.48, 1.7254, 1.7254, 1.7886, 1.8364] 	# eenheidspr 

Does my data make sense? Let's compare it to a few others out there:

  • Our water provider De Watergroep has a nice rate list of domestic water price, including history going back to 2018. The base unit price is exactly the same as in the above graph. It predicts a price of €1.9652 for 2022. Here we go again... Rates for disposal stayed constant.
  • The Flemish government keeps track of average water usages per household. For a family of 2, like us, it's 65 cubic meters a year. We're at 52 for the moment---better than the average! The site is very interesting, and shows that for each province, the average usage differs. We're in the orange zone. The Excel sheet claims average usage for 2 in Hasselt is 65.96, while for instance at the coastline in Oostende, it's 55.81, and in Antwerp, it's 79.21.
  • How to compare this to the rest of the world? Iwa network's graph shows the "Total Water Delivered for HouseHolds in 2018" (cubic meters per capita per year, so multiply by 2 for us). Belgium can be found all the way down (31.65). In The Netherlands, they use 48.44 per capita.

Vmm claims that the average water usage---only taking tap water into account---has slightly decreased over the years until 2020. To be fair, we stopped using tap water for preparing tea the last few years, buying bottled instead. I know it's bad, but having to drink tea that smells like a disinfected pool is much worse. The amount of chlorine that sometimes comes out of the tap is insane. When we take a bath, we sometimes feel like going to the local swimming pool. This depends on where your water is sourced from, and we happen to live on the edge of our municipality where the water is pumped over a long distance, resulting in too much chlorine to enjoy tea.

We do have a well for groundwater, but it's not installed and calls for separate piping and drilling in order to use that for the toilets. Perhaps we should add it to the TODO list after all...