Posts Tagged ‘creeks’

Joel speaking at the Exploratorium

Joel spoke at the Exploratorium on July 15th, 2015 exploring in conversation and images “Seep City” – a catalog of water discoveries in the city of San Francisco.

Joel’s map of Seep City shows today’s landforms, but overlays the springs, water, and waterways of the past (I like how the map is a lacking in any streets — makes it funner to try and identify the places you know). Crissy field used to be much larger (the current marsh is a “sculpture of a marsh”), and there were large marshes on the eastern side of the city, a tidal waterway running up to the Mission District, and Islais creek wending it’s way into the peninsula. The sands also held many temporary lakes and water ways that would come and go with storms (and the shifting sands). They are barriers and dams, but could be blown away in a storm. Creeks flowing out of the dunes were often temporary or seasonal.

San Francisco — unlike a lot of cities — is not built on a river, and a question you might ask is why we have these seeps and springs at all. If you stripped all our human construction and put back features we’ve flattened or otherwise shaped, you’d find a lot of sand, as well as some serpentite and chert. Before all of our hardscape, rainwater would have been absorbed by sand and passed underneath it, but there is also water coming out of the tops of hills despite the drought. Joel still has yet to answer the question where this exactly comes from.

There were someplaces the water always flowed. The Ohlone, not a stone age people, but perhaps better described as people of the fabric age, made use of water based technology and had daily rituals washing in the creeks here. But there were only a few hundred there when the Spanish arrived.

The Spanish built their settlements in San Francisco around a couple of springs, in the Presidio and in the Mission. Captain Anza noted the spring that flowed out of the dunes near where the Mission was to be built was enough for a larger water wheel.

As the city developed, San Francisco used local water for laundries and for bottling, water was brought around the city through flumes built by private companies selling water to the more settled regions of the city. Lobos creek was one of the sources the flume running along the coast. Another had a water works that created stow lake. Safeway in the Mission/Castro area used to be a reservoir with water pumped over the hills from outside of San Francisco. Tank hill had a tank of water.

Water was also stored around the city for fighting the frequent fires of San Francisco’s early days. You may see the circle and square bricks circling intersections of San Francisco Streets. These continue to hold water for fighting fire.

Most of our water no comes from outside of San Francisco. The Presidio gets 80% of its water from its own springs. And lot of that water still flows, just mostly out of sight, channelized and covered over. There are of course many more water features now in the way of fountains and reservoirs, and some of that come from local water. The fountain in UN plaza (7 piles of stone representing the 7 continents apparently) actually runs on ground water that people refered to as Hayes Creek. BART has to pump water of its tunnels continually. Water runs under the Armory building in the Mission. There is a brewery at Haight and Steiner which hope to use the water underneath their store. The presidio has a creek you can shut it off in 3 places in case someone falls in.

This map is of course just a start, there are seeps and springs all over the city, and while this map holds many — Joel continues to hear of new possible springs and seeps. Keep up to date with this project at his website: seepcity.org

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This will be our first of three summer talks partnering with the Exploratorium Bay Observatory Gallery. Please note the time and directions. Please also call or email ahead to let them know if you are coming (see reservations and directions at the bottom)

Exploring SF’s Natural Springs & Creeks
Guest Speaker: Joel Pomerantz
7pm Wednesday, July 15th, 2015 (doors after 6pm)
FREE at the Exploratorium Bay Observatory Gallery (see directions at the bottom for details)
and please let them know if you are coming.

Bernal Seeps

Which is more likely in San Francisco: wading through a creek or through traffic? Under the right circumstances, either is possible to do. Sometimes, when atmospheric rivers slam the region, we can do both at once, as street gutters fill to capacity. But San Franciscan residents have few if any natural creek experiences. Compare that to the creek-dependent lives of the people that lived here for thousands of years before urban development and you might start to wonder.
Bring your curiosity and wonder for this discussion-oriented presentation by Joel Pomerantz, an independent researcher and publisher of the Seep City water explorations map. He will give tips on reading the landscape in search of water, and tell you where some of our beautiful (if small) springs are.
You can read some of the recent media coverage on wired.com or order a map on his website seepcity.org.
Reservations can be made at reserve@exploratorium.edu or 415-528-4444 option 5.
Please let the Gallery know if you are coming.
The lecture will be at the Exploratorium Bay Observatory Gallery at the back of the museum. The special event entrance is through the gate on the outside of building, past the main entrance (as depicted in the map). Someone should be out front helping guide (the museum itself will not be open). Please visit the Exploratorium website for directions to the museum.

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Creeks to Sewers

Joel Pomerantz and Greg Braswell came out to talk to us May 15th about creeks and sewers. One particular creek in fact, Precita Creek, and how this creek was developed to the sewers that are there today.

Joel walked us through the natural flow of this creek and early history. The name Precita comes from a Spanish word meaning dam or weir. Native Americans would use weirs which were funnels with a basket in the middle into which they would drive the fish. The creek flows down from under where Market Street is today (from the Mission Mountains according to early maps), down along the north side of Bernal Heights and through the gap between Bernal and Potrero into Islais Creek. The creek has left it’s traces in odd little bends in streets (Joel was hoping to have Burrito Justice join us, but alas!).

The creek ended in the wetlands that pushed up through this gap, and the water joined Islais creek. For early San Franciscans this swampy area ended up in the late 1800s a perfect dumping ground for fill, effluents from tanneries and soap factories, and their sewers. The word fetid probably does not do it justice.

The first master sewer plan was in 1875, and many more have since followed. Before that there was a lot of add hoc sewers that did not really go anywhere (This talk almost cured me of my nostalgia for seeing San Francisco back in the day!). The first houses in this area were built in the 1860s and some had wooden sewers bringing waste down the hill.

The 1875 Humphrey plan had to get the state legislature to redraw streets for the plan to go forward. And it wasn’t til 1881 that a sewer was complete under (now) Cesar Chavez. The brick arch of this sewer was 11.5′ wide and 8′ tall. It’s had work done it since, but it is in essence still in use today.

The sewers extended out into the Marsh becoming the bones in a sense of later fill. The earthquake and fire of 1906 provided a lot of that fill.

The city didn’t see its first treatment plants to around the ’30s. Plants in Golden Gate Park and Fort Point. The SW treatment plant wasn’t built until the 40s. The city treats both sewer and storm water in one system — and for good reason — the water that falls onto San Francisco takes with it a lot of nasty crap, which we wouldn’t want pouring back into the oceans.

One could sense that Greg could tell amazing stories about just about any piece of our sewer system. Whether its current state, or how it came to be the way it is today.


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