In an emergency such as a fire you want to be able to escape from a building quickly and be assured that there’s plenty of water to fight the flames. I presume these capped pipes have something to do with that purpose?
Except where stated in the post, photos posted on or after January 1st, 2014 are licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Basically, do what you like with those images but always credit Donncha Ó Caoimh as the author and link here. You'll also have to license the photo under the same license.