If there’s one thing that everybody thinks they know about Germans, it’s that they’re green. Germans think they know this about themselves too, and can point to neighbour-shaming recycling figures and ambitious plans to switch entirely to renewable energy to prove it.

Then there’s the strength of the German Green Party, which regularly garners 10 per cent of the national vote, and the small everyday reminders that efficient resource use doesn’t automatically entail hair shirts and self-flagellation: just witness the nationwide deposit scheme in which a beer bottle is actually worth 0.08 euros (six pence) on returning it to the shop. Money for your empties: like so much out here, it’s a beer-drinker’s dream come true.

As a matter of fact, Germany’s green attitude is one of the things I find most attractive about it, and precisely because of this admiration, there are some inconsistencies about German environmental behaviour which really niggle me.

Like their annoying obsession with bottled water. Germany is a country with British levels of rainfall and a, well, German plumbing infrastructure. This happy coincidence means that, if there’s one natural resource Germans will not be running short on any time soon, it’s tap water, which is reflected in enviably low water rates. We pay around 15 euros per month (£12.35) as a two-person household, and enjoy deliciously high water quality.

And yet Germans refuse en masse to make use of this cheap, practical resource. Especially in middle-class homes, not having both still and fizzy bottled water, chilled, to offer guests is a faux-pas on the level of welcoming somebody into your home in Britain without having the necessaries to offer them a cup of tea.

This keeping-up-with-the-Schmidts attitude to H20 leads to truly ridiculous spectacles every Saturday morning, as couple after work-week-weary couple clogs up the supermarket till to pay top euro for crates of a substance they have in equal quality and all-but-unlimited measure at home. Then there’s the mass schlepping of said precious substance to their cars, with much huffing and puffing, followed by the positively Sisyphean task of hauling the whole load up several flights of stairs (city dwellers tend to live in blocks of flats). Call me crazy, but I prefer to save my shopping-run energy reserves for savoury, nutritious stuff that doesn’t come out of a tap in my kitchen – like milk, potatoes, or indeed beer (although I’m working on that last one).

While many Germans seem anxious to avoid tap water, most will drink it if pressed – either by me, or by an oncoming fit of dehydration of a hot Sunday afternoon when Lidl and Aldi’s water reserves are firmly behind closed shop shutters. Yet there is one group of Germans who would literally rather people thirsted to death than drink tap-water: restaurateurs.

In any country, there’s always a guaranteed way of getting your food spat on. In France, it’s finger-clicking and yelling “garçon” in an audibly English accent; in Ireland, it’s just being English. Yet the way to get flob on your Flammkuchen (pizza) in Germany is simply to ask for tap-water with your meal. In a German ordering situation, it’s one of the rudest things you can do (short of going all Basil Fawlty).

This comes from a fundamental difference of opinion about pricing and the role of water. In most countries, water is considered an essential accompaniment to food (in several, it is illegal to refuse it to guests in eateries); in Germany, it is considered a way to recoup costs on alluring prices for meals with which restaurant owners would otherwise be cutting their own throats. Especially when dining on an attractively priced midday offer, customers who do not order a beverage of some sort are probably costing more than they’re paying. Elsewhere, restaurants would rectify this by upping the price of their food; in Germany, the solution is to get arsey if the customer doesn’t play the game and order some form of high-margin liquid refreshment.

In fact, in general, the tap-water issue in Germany is a financial one. Drinking bottled water was once a way of displaying wealth, one that has become so culturally ingrained that the automatic mental response when someone insists on tap-water is to consider them a pfennig-pincher – rather than, say, someone who sees it as morally questionable to spend loads of money and emit huge amounts of carbon dioxide bottling and transporting water when it’s readily available everywhere: too much CO2 for H2O, if you like.

In fact, carbon emissions is where German inconsistencies with regards to the environment become quite flagrant: as the Green vote in Germany expands, so does the average engine rating on vehicles sold. Meanwhile, Angela Merkel’s government blocked tighter European emissions standards last year to favour the country’s high-horsepower car manufacturers – at precisely the same time as it was supposed to be formulating policies for the carbon-free energy switch.

If only the boffins at BMW could come up with a way of running luxury vehicles off of the gas bubbles in fizzy bottled water, this expat Swampy might finally be satisfied…