California Reservoir Status as maintained by the Army Corps of Engineers:
https://www.spk-wc.usace.army.mil/fcgi-bin/midnight.py?days=...
1 acre foot is 43560 feet^3, or 1233 m^3 of water.
https://www.spk-wc.usace.army.mil/fcgi-bin/midnight.py?days=...
1 acre foot is 43560 feet^3, or 1233 m^3 of water.
m³ is already a pretty hard to visualize unit (unless you are used to visualize volume) but acre feet is just about impossible.
A single m^3 is fairly easy to visualize, but once you get to higher amounts it's pretty meaningless.
An alternative is using "known" points of reference like Olympic swimming pools, the Sistine Chapel etc (similar to "an area the size of Belgium"). But that risks getting absurd.
Idk about the US but in Europe 1m³ water tanks[0] are extremely popular as rainwater collectors. Also they are approximately the size of a pallet, another popular item.
Whereas acre feet, since I don't know what both units are... But "are meter" wouldn't help either, to be fair.
[0]: https://www.multicuves.com/2049-thickbox_default/kit-eco-de-...
Acres can be any shape, but gp is correct that acres were originally defined as chain x furlong (per wikipedia https://en.wikipedia.org/wiki/Furlong ). They're also correct that it's a weird combination of disparate sizes which doesn't lend itself to visualization.
On the other hand, for many people it’s easier to visualize than you might imagine. As you may know, virtually the entire US was surveyed and divided up into one mile × one mile sections. A square mile is exactly 640 acres. At one time a homesteader could buy that square mile and move west. Over time the minimum size of a homestead was halved and halved again until it was 160 acres, or one quarter of a square mile, around the time of the Civil War. These were often quartered again into 40 acre fields. A farmer and his family could expect to work two or three of those fields every year, rotating which one was fallow if they were smart. They are ¼ of a mile on a side.
You can zoom in on almost any random part of the US and find those squares everywhere. Farmland is all gridded with roads along the 1 mile section boundaries, and cities are a jumble. But in between the suburbs are made up of the smaller divisions. It is very common for a 40–acre field to be divided up into 13 lots of ~3 acres each. It is super common to find whole areas of 10–acre lots made by quartering those fields. And it is also not surprising to find a 10–acre lot that has been divided up into 1 acre lots that are all 66ft×660ft.
Here, as an example I [zoomed into a randomly–chosen point in the midwest](https://www.google.com/maps/@39.6540747,-86.0094355,1456m/da...). If you measure E McGregor Rd along the northern edge of the map you’ll find that it’s 1 mile long until it hits that jog. You can immediately see that this section was subdivided into four 160–acre farms, and some of those were subdivided into 40–acre fields. Knapp Rd runs north–south and divides the section in half. To the east is an older area of mostly 2, 3, and 5–acre lots. On the western side a developer has bought up 90 acres (two 40–acre fields connected by a 10–acre lot) and turned it into a very modern subdivision of houses each built on (approximately) half–acre lots. For many Americans, visualizing an acre is easy; it’s half the size of the land their house was built on, or their lot plus their neighbor’s lot, or some other similar amount.
The acre-foot is a nice manageable size. Plus if you know you’ve got 160 acres planted, and you need 6 in of water over everything, it’s pretty easy figure the volume to request
That's a furrow width x a furrow length. I imagine our agrarian roots have something to do with this. Then you can easily find tables for expected food production from 1 acre of your crops.
> weird rectangular cuboid
A good 1:10 crop row.
> m³ is already a pretty hard to visualize unit
1000 1L bottles doesn't seem that hard to visualize.
Square is great in a science book but land and reality is easier with divisions by 2,3,4,6,8 etc
If you are a farmer with 26 acres of field that need to be irrigated the equivalence of 1 foot of water every 2 weeks throughout the dry season which is expected to last 3 months, it is easy to calculate that you need 26 × 6 acre feet of water for that. But ones you use volume for literally anything else the flaws of the unit become very apparent.
I don't think it's that hard; just think of a standard 1000L water tank (which is, in my experience, the most common size).
It's 264 US gallons. So presumably sold as a 250 gallon tank with a bit of extra headroom.