"San Francisco is still a place where you can see water seeping up from the sidewalk or coming out of a hillside, but people don’t even know it’s there,” natural history writer and educator Joel Pomerantz tells Wired. His successful Kickstarter campaign allowed him to complete his map and book on the subject of San Francisco's natural streams, lost and found. It's called Seep City.

Of the natural waterways Pomerantz documents, he writes, "The water in San Francisco is a window into the city's past... 'natural state' before the streets, neighborhoods and the built landscape we see today were created."

Pomerantz first got his feet wet in geological cartography during the mid 1980s, and over the course of his research he's made plenty of cool discoveries. For example, did you know there was a bottling company in the Mission that drew groundwater? That one is a subject in one of his lengthy essays.

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Pomerantz and others also point to today's Wiggle as a prime example of what they mean when they talk about hidden or past waterways. What's now a zig-zagging bicycle route was once was an old stream bed, as illustrated by a mid-1800s photograph with a line of willow trees. The trees, Pomerantz explains, indicate water below the ground surface.

During recent seismic renovations, a forthcoming brewery along that route called Black Sands even struck some water below their storefront. Not wasting a drop, they're considering using it for cleaning and even, if it's safe and legal, brewing.

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Speaking of that "waste not" mentality, Pomerantz hopes that there might be renewed interest these days in getting more of SF's natural water out from under the city. Sure, Hetch Hetchy is pretty full, but Pomerantz observes that “Recent changes in Water Department policy allows for a few percent of SF’s tap water to be from the Westside Basin aquifer, mixed in to the rest of the supply... Also, Golden Gate Park and the Presidio's water (including its tap water) are mostly from groundwater sources now.”

Here's a charming promo video from Pomerantz. That music? It's him on the harmonica, of course.

Related: Market Street Project To Remember Forgotten Waterways

A view of Bernal Heights