"I drain the cups before dawn."
Translation:Pocula ante auroram exhaurio.
There’s some examples on the search engine "Mlat"; «haurio» seems to be a close synonym of «exhaurio», the only difference being that, when something is «exhaustus», there's no water left, it's drained away; if it's «haustus», as the examples will show, the drained water is there to be used, it's drawn, almost extracted.:
«Est autem etiam cocleae ratio, quae magnam vim haurit aquae, sed non tam alte tollit quam rota».
[There is also a system for [using] the screw which draws a large quantity of water, but does not raise it as high as a wheel does]. —Vitruvius, De Architectura, 10, 6, 1; 1 (opus c.33BC).
«huc venit incinctus tunica mercator et urna
purus suffita, quam ferat, haurit aquam».
—Ovidius Naso, Fasti, 4; 582.
[Here the merchant, washed and draped [in his tunic], draws/drains water,
which he carries off in a disinfected jar].
In prosa posita
Huc venit Mercator purus et tunica incinctus, haurit aquam quam ferat urna suffita.
Search results for «haurit»: http://www.mlat.uzh.ch/MLS/advsuchergebnis.php?suchbegriff=haurit&table=&level2_name=&from_year=&to_year=450&mode=SPH_MATCH_EXTENDED2&lang=0&corpus=all&verses=&lemmatised=&suchenin=alle
The Vitruvius example is governing an accusative: magnam vim "a great amount" is the accusative, on which the genitive aquae depends ("a great amount of water"). Or, in the translation you supply, "a large quantity" of water.
(vīs is an irregular noun that basically only exists, in the singular, in the accusative vim and the ablative vī .)
A very useful construction, thanks for that. Very interesting that it functioned mainly in the accusative. Some more instances of it, one of them meaning "a great amount" like you say:
«O magnam vim numinis vestri!».
[Oh immense power of your divinity!].
—Panegyrici Latini (c. 300).
«...atque incensa civitate magnam vim praedae trahit, abducens Tecmessam, filiam regis».
[…and with the city in flames, a huge portion of the plunder is squandered, ravishing Tecmessa, the king’s daughter].
—Dictys Cretensis, Ephemeris belli Troiani.