May 2020 was unusually hot. According to European service Copernicus, May 2020 was the hottest since the beginning of the measurements. But May 2022 is also unusually hot---and very dry. In Belgium, so far, there has been 1 mm of rain, that would be the second driest month since 1983, where only 37.6 mm of rain was measured during the whole spring period. This persistent period of drought regularly appears in the local news:

Het neerslagtekort in Vlaanderen is op dit moment al groter dan dat van de extreem droge zomers van 1976, 2018 en 2020. Dat blijkt uit cijfers van professor waterkunde Patrick Willems (KU Leuven).

(The precipitation deficit in Flanders is on this moment already bigger than that of extreme dry summers of 1976, 2018, and 2020. This is evident from numbers of hydrology professor Patrick Willems (KU Leuven)).

The article then proceeds to deal out very practical tips such as "do not leave the tap running" (really?) and "place a rain barrel in your garden". Aha, we'll get back to that.

I care about the weather, not only to have something to say when greeting neighbors during a walk with the dog, but also because I want my lettuce, courgette (I'm sorry Americans, sure, summer squash, whatever), and beets to grow. We only have a humble vegetable garden, and every single year I'm too late to the party or forget to sow, but it's still something I deeply enjoy. Rooting in the earth takes me back to earth and keeps me away from a keyboard. Sometimes the chickens are permitted to help.

These thirsty plants thrive with the right combination of sun, compost, and water. The latter is becoming a problem. My father has a huge greenhouse that is served by a combination of a groundwater well plus catching plenty of rainwater, while we only have a meager 220 l water barrel connected to the drains of our garage. If I'm being very frugal, the garden requires at least four refills of a 5 l watering can. That means within ten days, our barrel is empty.

The alternative is tap water, which is getting very expensive too, next to the ridiculous natural gas prices. The unit price of a cubic meter of water was €1.9652¹ in March (excluding various fixed costs), which would be €0.039 for 20 l of vegetable joy. Even though that doesn't sound like much, I'm being very conservative on the calculations, and I'd rather "catch it falling" instead.

How much rainwater can we catch, though? There are handy tools for this (in Dutch) that, depending on your location (Limburg: average rainfall of 62.5 mm per month), the size of the garage roof (60 m², just a wild guess) and type of roof (tiles, flat, ...) gives an estimate on how much rain you can collect in a year: 40 m³ or 181 times the 220 l water barrel. That sounds like a lot of room for improvement! The calculator suggests to install a water tank of 3 m³, while we have one of 0.22. Ouch.

Except that the Belgian KMI institute measures on average 46.7 mm total rainfall each month instead of the above 62, and it's likely going to drop even further. Also, DuckDuckGo's image search result for "water barrel" is much more modest, like the one we have in the photo above, compared to a "water tank"---a huge container we first have to figure out where on earth to put! Likely, indeed, on earth, preferably our own personal piece of earth. I'll ask the chickens to move. Again.

I'm not quite sure where I'm going with these numbers, except that I need to remind myself to attach the second barrel we have lying around for a while now.

There's an upside to the persistent drought: no pesky snails that make the tiny plants disappear.

Addendum, 17th May: Michael Hamann suggested to use a mulch method which involves a layer of hay to drastically reduce the need to water the vegetable garden. This is supposedly called the Ruth Stout method. Interesting, thanks Michael!