Let us be thankful for Rob St John's plumbing woes.

Were it not for a pipe-drain drama at the alt-folk topographer's Edinburgh flat, and a subsequent chat with his landlord - better known as art-pop whiz Tommy Perman - we may not have their collaboration Water Of Life.

Funded by Creative Scotland's Year of Natural Scotland and inspired by Edinburgh's water network, it's an enthralling underground guide to the city that includes performances and talks, a seven inch record with prints and essays, and a groundbreaking water-borne sound-map of Edinburgh which will contribute to the British Library's UK-wide natural archive.

Their liquid cartography was informed by geography and mythology. "The starting point was to scour an OS map, marking all the water I could find," says St John. "These became the first points for fieldwork. The second strand was the research I carried out in the National Library of Scotland and City Archives, trying to trace the histories of water in the city, which often wheeled off into fascinating social and cultural histories."

Perman, formerly of the band and art collective Found, takes us on a leafy city-centre voyage to a vital site: the nettle-entangled and partially derelict 17th-century Comiston springs water house, which serviced the city until the early 1700s.

You can still hear the water burbling, if you put an ear to the iron door, and it's one of many field-recordings that blurs with folksong and ambient electronica on the Water Of Life compositions.

The tanks in the water house were originally watched over by lead animals (fox, swan, lapwing, hare and, according to legend, a now-missing owl), who give the nearby forgotten well heads and residential streets their names, and whose mythology (they were thought to represent a conduit between real and imagined realms) permeates St John's accompanying essays and Perman's visual art.

The area distils the essence of Water Of Life: it questions perceptions of, and boundaries between, natural and man-made contexts; it demonstrates the inextricable (and harmonious) relationship between nature and industry, science and folklore; it reflects a constant, yet constantly unknowable, source. It gives water a voice.

Did the pair's collected found-sounds from Comiston springs, and neighbouring reservoirs, lochs and bathtubs, steer the project's musical narrative? "I wouldn't say that they directly informed the chords and musical motifs we wrote," Perman offers. "I think the stories and their themes informed that more. For example, I wrote a piece of music responding to Comiston springs, which has a little melody for each of the animals - and one of them, the owl, isn't there, so the music for that's kind of sparse."

St John agrees. "The first track on the single takes a set of recordings close to the source of the Water of Leith, and leads into an organ melody inspired by Basil Kirchin and post-war plans for the city's environment. The second is based on the idea of water constantly being reworked, blended and channelled away under our feet in pipelines and, finally, the sewage works. We ended it with a snatch of a tune about The Shellycoat, a watery spirit which is said to haunt a boulder, The Pennybap, which was previously off the shore at Seafield, and now sits in the car-park of some office buildings next to the sewage works.

"The tracks were created using recordings from the sound-map as drones, texture and percussion, like dripping taps and stones moving underwater, alongside a limited set of instruments - transistor organ, harmonium, synth and iPad," St John continues. "We wanted to reflect the hybrid nature of water in the city: constantly in flux, a blend of the environmental and social; technological and folkloric."

Perman nods: "We wanted to tell the story of a landscape and human interaction with it, and their impact on it, so it made sense for us to edit and respond to the sounds, not just have unadulterated field recordings. It felt like we were doing what we were seeing around us. Everything fed into everything else."

And it does. Water Of Life underscores the significance of water at every level, and indeed the importance of art: it re-maps our physical and imagined landscapes; it changes our perceptions of our day-to-day surroundings; it makes us reassess the world(s) around us, and beneath our feet.

Water Of Life performances, Summerhall, Edinburgh (part of Folklore Tapes' Echo Of Light), November 7 and 8. The seven inch single is released on December 9