Tag: cistern

Cistern Mapping Project Reportback

On October 11th, 2015, 18 volunteer bike and mapping aficionados gathered at my place to work on the Cistern Mapping Project — an endeavor to physically document the 170 (or so) Cisterns in San Francisco. There exists no comprehensive map of these unique underground vessels. The resulting map is here.

I personally became fascinated by them, when working on my Water Works project*, which mapped the water infrastructure of San Francisco.

The history of the cisterns is unique, and notably incomplete.

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The cisterns are part of the AWSS (Auxiliary Water Supply System) of San Francisco, a water system that exists entirely for emergency use and is separate from the potable drinking water supply and the sewer system.

In the 1850s, after a series of Great Fires in San Francisco tore through the city, about 23 cisterns were built. These smaller cisterns were all in the city proper, at that time between Telegraph Hill and Rincon Hill. They weren’t connected to any other pipes and the fire department intended to use them in case the water mains were broken, as a backup water supply.

They languished for decades. Many people thought they should be removed, especially after incidents like the 1868 Cistern Gas Explosion.

However, after the 1906 Earthquake, fires once again decimated the city. Many water mains broke and the neglected cisterns helped save portions of the city. Afterward, the city passed a $5,200,000 bond and begin building the AWSS in 1908. This included the construction of many new cisterns and the rehabilitation of other, neglected ones. Most of the new cisterns could hold 75,000 gallons of water. The largest one is underneath the Civic Center and has a capacity of 243,000 gallons.

The original ones, presumably rebuilt, hold much less, anywhere from 15,000 to 50,000 gallons.

Cistern109 22nd Dolores

Armed with a series of intersections of potential Cistern Locations, the plan was to bike to each intersection and get the exact latitude and longitude and a photograph of each of the cistern markers — either the circular bricks or the manholes themselves.

We had 18 volunteers, which is a huge turnout for a beautiful Sunday morning. I provided coffee and bagels and soon folks from my different communities of the bike teamExploratorium and other friends were chatting with one another.

Cistern Prep Meeting 3

One way to thank my lovely volunteers was to provide gifts. What I made for everyone were a series of moleskine notebooks with vinyl stickers of the cisterns and bikes. I was originally planning to laser-etch them, but found out that they were on the “forbidden materials” list at the Creative Workshops at Autodesk Pier 9, where I made them. Luckily, I always have a Plan B and so I made vinyl stickers instead.

Cistern Prep Meeting 4Cistern Prep Meeting 1

Here I am, in desperate need of a haircut, greeting everyone and explaining the process. I grouped the cisterns into blocks of about 10-20 into 10 different sets. This covered most of them and then we paired off riders in groups of 2 to try to map out the best way to figure out their ride.Cistern Prep Meeting 2

Some of the riders were friends beforehand and others became friends during the course of riding together. Here, you can see two riders figuring out the ideal route for their morning. Some folks were smart and brought paper maps, too!

Cistern Prep Meeting 7

Here are the bike-mappers just before embarking on their day-of-mapping. Great smiles all around!

 

Cistern Group 1

I would have preferred to ride, but instead was busy arranging the spreadsheet and verifying locations. Ah, admin work.

How did we do this? Simple: each team used a GPS app and emailed me the coordinates of the cistern marker, along with a photo of the cistern: the bricks, manhole or fire hydrant. I would coordinate via email and confirm that I got the right info and slowly fill out the spreadsheet. It was a busy few hours.

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The hills were steep, but fortunately we had a secret weapon: some riders from the Superpro Racing team! Here is Chris Ryan crushing the hills in Pacific Heights.

Cistern chris uphill

One reason that we traveled in pairs is that documentation can be dangerous. Sometimes we had to to put folks on the edge or actually in the street so they could get some great documentation.

Cisterns chris

So, how many cisterns did we map? The end result was 127 cisterns, which is about 75% of them, all in one day. We missed a few and then there were a series of outliers such as ones in Glen Park, Outer Sunset and Bayview that we didn’t quite make.

And the resulting map is here. There are still some glitches, but what I like about it is that you can now see the different intersections for each cistern. These have not been documented before, so it’s exciting to see most of them on the map.

Cistern web map

What did we discover?

Most of the cisterns are not actually marked with brick circles and just have a manhole that says “Cisterns” or even just “AWSS” on it.

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What I really enjoyed, especially being in the “backroom” was how the cyclists captured the beautiful parts of the city in the background of the photos, such as the cable car tracks.

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Also, the green-capped fire hydrants usually are nearby. These are the ones that get used to fill up the cisterns by the SF Fire Department.

Green hydrant

A few were almost like their own art installations, with beautiful brickwork.

Cistern118 24th Noe

The ones in the Sunset and Richmond district are newer and are actually marked by brick rectangles

Cistern135 46th Geary

Thanks to the AMAZING volunteers on this day.

* Water Works is supported by a Creative Code Fellowship through Stamen Design, Autodesk and Gray Area.

Modeling Cisterns

How do you construct a 3D model of something that lives underground and only exists in a handful of pictures taken from the interior? This was my task for the Cisterns of San Francisco last week.

The backstory: have you ever seen those brick circles in intersections and wondered what the heck they mean? I sure have.

It turns out that underneath each circle is an underground cistern. There are 170 or so* of them spread throughout the city. They’re part of the AWSS (Auxiliary Water Supply System) of San Francisco, a water system that exists entirely for emergency use.

The cisterns are just one aspect of my research for Water Works, which will map out the San Francisco water infrastructure and data-visualize the physical pipes and structures that keep the H2O moving in our city.

This project is part of my Creative Code Fellowship with Stamen Design, Gray Area and Autodesk.

Cistern_1505_MedRes

Many others have written about the cisterns: Atlas Obscura, Untapped Cities, Found SF, and the cisterns even have their own Wikipedia page, albeit one that needs some edits.

The original cisterns, about 35 or so, were built in the 1850s, after a series of great fires ravaged the city, located in the Telegraph Hill to Rincon Hill area. In the next several decades they were largely unused, but the fire department filled them up with water for a “just in case” scenario.

Meanwhile, in the late 19th century as San Francisco rapidly developed into a large city, it began building a pressurized hydrant-based fire system, which was seen as many as a more effective way to deliver water in case of a fire. Many thought of the cisterns as antiquated and unnecessary.

However, when the 1906 earthquake hit, the SFFD was soon overwhelmed by a fire that tore through the city. The water mains collapsed. The old cisterns were one of the few sources of reliable water.

After the earthquake, the city passed bonds to begin construction of the AWSS — the separate water system just for fire emergencies. In addition to special pipes and hydrants fed from reservoirs for hydrants, the city constructed about 140 more underground cisterns.

Cisterns are disconnected nodes from the network, with no pipes and are maintained by the fire department, which presumably fill them every year. I’ve heard that some are incredibly leaky and others are watertight.

What do they look like inside? This is the *only* picture I can find anywhere and is of a cistern in the midst of seismic upgrade work. This one was built in 1910 and holds 75,000 gallons of water, the standard size for the cisterns. They are HUGE. As you can surmise from this picture, the water is not for drinking.cistern(Photographer: Robin Scheswohl; Title: Auxiliary Water supply system upgrade, San Francisco, USA)

Since we can’t see the outside of an underground cistern, I can only imagine what it might look like. My first sketch looked something like this.

cistern_drawingI approached Taylor Stein, Fusion 360 product evangelist at Autodesk, who helped me make my crude drawing come to life. I printed it out on one of the Autodesk 3D printers and lo and behold it looks like this: a double hamburger with a nipple on top. Arggh! Back to the virtual drawing board.IMG_0010I scoured the interwebs and found this reference photograph of an underground German cistern. It’s clearly smaller than the ones in San Francisco, but it looks like it would hold water. The form is unique and didn’t seem to connote something other than a vessel-that-holds-water.800px-Unterirdische_ZisterneOnce again, Taylor helped me bang this one out — within 45 minutes, we had a workable model in Fusion 360. We made ours with slightly wider dimensions on the top cone. The lid looks like a manhole.

cistern_3d

Within a couple hours, I had some 3D prints ready. I printed out several sizes, scaling the height to for various aesthetic tests.

cistern_models_printed

This was my favorite one. It vaguely looks like cooking pot or a tortilla canister, but not *very* much. Those three rectangular ridges, parked at 120-degree angles, give it an unusual form

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Now, it’s time to begin the more arduous project of mapping the cisterns themselves. And the tough part is still finishing the software that maps the cisterns into 3D space and exports them as an STL with some sort of binding support structure.

* I’ve only been able to locate 169 cisterns. Some reports state that there are 170 and others that there are 173 and 177.