water buffalo
n.— «Other times foundations fracture and wells crack, the water draining away. “Water buffalo”—the local term for replacement water tanks wrapped in white insulation—graze in backyards and side lots.» —“In The Black” by Jane M. Von Bergen in Waynesburg Philadelphia Inquirer (Pennsylvania) May 11, 2008. (source: Double-Tongued Dictionary)
Further reading
A retronym is a word coined to distinguish something new from an older, more generic version, such as electric guitar or clock radio. A couple of new retronyms are fine water, or “unprocessed water that reflects a region’s terroir” and water...
Ribbon fall. Gallery forest. You won’t find terms like these in most dictionaries, but they and hundreds like them are discussed by famous writers in the book Home Ground: A Guide to the American Landscape. The book is an intriguing collection...
I don’t know if your American readers are aware of it, but there’s an actual, literal water buffalo, defined by Merriam-Webster as “an often domesticated Asian buffalo.” The Philippine carabao (kalabaw in Tagalog and karabaw in Visayan, another Philippine language) is a water buffalo.
water buffalo (n)
1. a small two wheel trailer used by US Army and Air Force to transport potable water to troops in the field
2. Colorado has arcane water laws with the chief tenet being ‘first user has first right.’ A long-time expert lawyer in this field of law is nick-named a ‘water buffalo’.
Who coined the term and when.
This water trailer is far from the looks of a buffalo. I think it looks more like a pig.