This expression is applicable to a situation where a certain
negative development is going on for some time, and is getting out of
hand at some point.
A "spuigat" is a so-called scupper: an opening in the hull of a ship,
at deck level, for purposes of draining water. "Het loopt de spuigaten
uit" literally means: It (i.e. water) runs out of the scuppers. So when
water is draining from the scuppers, this means that the deck is
covered in a layer of water, which is an undesirable situation…
If you want to specify the thing or situation that is getting out of
hand, you say: "Het loopt de spuigaten uit met [thing/situation]", see
the Examples. A related word is "spui" which you might recognize if you live in The Hague or Amsterdam, see below.
– "Het loopt de spuigaten uit met de criminaliteit in de grote steden."
("Crime is getting out of hand in the big cities.")
– "Ik kan niet meer tegen het gedoe…het loopt de spuigaten uit!"
("I can’t stand the fuss anymore…it’s going too far!")
– "Dit gaat te ver": this is going too far.
– "Dit loopt uit de hand": this is getting out of hand. Lit.: this walks out of the hand.
– Spuien: to drain (off), to sluice surplus water [verb] [spuide, gespuid]. Note that "spuien" can also be used figuratively: to spout (knowledge/criticism etc.).
– Spui: the place in town where one would sluice surplus water in the old days. There is a Spui in at least Amsterdam and in The Hague.
– Gat: hole [noun] [het gat, de gaten].