A short rumination from Akiko Busch in the NY Times asks us to Learn a River’s Name Before It’s Gone resonated with me around the idea of language as the cultural thread that weaves.  Describing a road trip, where she wrote down the list of over 100 rivers crossed, concluding that “If we couldn’t hear the sound of the water itself, the syllables of the names became a new way for me to chart this country.”  The simple idea of knowing the name of something (or someone, for that matter) and although we go a bit crazy with naming storms, Busch posits that:

“it would likely be of greater benefit if we could find a similar pleasure in learning a few of the names that identify those features of the natural world we live with all the time. Which is to say, instead of making up new names, we might consider learning the names that already exist.”

Data and science are critical elements in understanding on many levels, but words and names provide a level of connection.  Busch continues: “Giving something a name is the first step in taking care of it. Place names help us to attach landscape to history and region. And when it comes to the question of attachment, we are not just speaking of how names are attached to places, but how humans become attached to places.”  Stories of places abound, and continued attacks on environmental regulations aims to further degrade our protections, so “perhaps we could make the effort to learn as many of the names of those places — and the trees, the rivers, the ranges, all the species that live there — as possible, before it’s too late.”

Robert Macfarlane, quoted in Busch’s essay above, says that “Once a landscape goes undescribed and therefore unregarded, it becomes more vulnerable to unwise use or improper action.”  To me he embodies the idea of naming and knowing, and I was fascinated by his take on the vibrancy of language, and the stories of how this language is being lost, and the need to retain it – from this Guardian article ‘The word-hoard: Robert Macfarlane on rewilding our language of landscape‘.  I wrote about this here in Landscape+Urbanism, and have been currently reading his book Landmarks, which breaks down place language in short essays interspersed with lists focusing on language specific landscape features.  The resources   The publication of his book led to him receiving a deluge of words from readers from around the globe,  Recently on Twitter, Macfarlane posts daily words and continues to collect new ones and has amassed a following of those interested in the word hoard.

This idea connects with other writers of lexicography, such as the fabulous book Home Ground: A Guide to the American Landscape, edited by Barry Lopez and Debra Gwartney, which provides  “descriptive language for the American landscape by combining geography, literature, and folklore” and those gems that have been formative for many landscape architects, such as Anne Whiston Spirn’s poetic Language of Landscape.  New forms are emerging as well, such as the Lexicon for an Anthropocene Yet Seen,   Many

Whose Language, Whose Culture?

The naming, of course, needs to respond to pre-European settlement, as much of the work of ‘finding’ hidden hydrology uses maps that are made by Europeans and often (purposely or ignorantly) erase place names that have be tied to places for years.  As we look back into history, we are challenged to find not just the names of places on a map, but to search a richer heritage of Native place names. The work on the Welikia Project explains: “The Lenape people inhabited Mannahatta for thousands of years before the Europeans arrived. They named their island home “Mannahatta,” meaning “Island of Many Hills.” We use the term “Mannahatta” to refer to the island as it was in 1609, and “Manhattan” to refer to the metropolis of today.”  When they expanded the concept to the larger NY City metro area, they also adopted the Lenape expression “Welikia,”meaning “my good home,” and infuse place making with Native settlement patterns often in their work.

The Waterlines Project here in Seattle is a great example of connecting Hidden Hydrology to Native language, providing on the map a key with Coast Salish Place Names.

The place names on this map, written in the Lushootseed language of the Coast Salish people, are drawn from elders who worked with ethnographers in the early twentieth century, from the work of linguists and scholars such as the late Vi Hilbert, and from an atlas created by Coll Thrush and Nile Thompson for the book Native Seattle.  Place names are stories: proof of presence, archives of meaning, evidence of ancestry, and a reference for treaties and other legal connections to territory. They provide context to the ongoing presence and strong connections to the city for Native people as co-managers of our shared resources. Refer to “An Atlas of Indigenous Seattle” for further information on the Native place names found on this map.”

I’m inspired to learn the names (those of the present, past and distant past) of the local places across history and dig into some of these local resources as I continue to compile my working base of Seattle and Portland Hidden Hydrology.  I found a post by local writer David B. Williams on his GeologyWriter blog – which was helpful in summarizing Seattle’s Stream Names, for the more recently naming, and soon to come is some documentation of my recent muddy exploration of Licton Springs, which is named for Liq’tid (LEEK-teed) or Licton (Item #9 above), the Lushootseed word ‘Red Paint’ for the reddish mud of the springs.

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Excited to see this announcement of a series classes focused around the Waterlines Project (see my post about it here as well).  The four week  ‘Waterlines Class Series‘ meets Wednesdays at the Burke Museum and costs $120 ($100 for Burke members), and aims to cover lots of territory on Seattle’s interesting landscape history.  From the site:

Wednesday, April 19, 2017
The Origins of Seattle’s Landscape
Dr. Stan Chernicoff
Discover the dynamic geological forces that shaped and continue to shape the lands of the Salish Sea. During his 30-year tenure at the University of Washington, geologist Dr. Stan Chernicoff established a unique rapport with his students and a mastery of subject matter. In 2000, he received the University of Washington Distinguished Teacher Award for lively curiosity, commitment to research and passion for teaching.

Wednesday, April 26, 2017
Before the Cut
Dennis Lewarch, Suquamish Tribal Historic Preservation Officer
Using archaeological, ethnographic and historical data, Dennis Lewarch disccuses the effects of shoreline transformations on indigenous populations. A professional archaeologist, Lewarch has worked in western Washington for over 30 years and brings useful insights that intertwine environmental change, archaeological data and tribal land use in the region.

Wednesday, May 3, 2017
Waterway: The Story of Seattle’s Locks and Ship Canal
David B. Williams
Find out what drove Seattle’s civic leaders to pursue the dream of a Lake Washington Ship Canal for more than 60 years and what role that canal has played in the region’s development over the past century. The author of Too High and Too Steep: Reshaping Seattle’s TopographyThe Seattle Street-Smart Naturalist and Seattle Walks: Discovering History and Nature in the City, David B. Williams also organizes the Burke’s annual Environmental Writer’s Workshop. His upcoming book, Waterway, will be out June 2017.

Wednesday, May 10, 2017
Reclaiming the Duwamish
Eric Wagner and Tom Reese
Eric Wagner and Tom Reese, author and photographer of Once and Future River: Reclaiming the Duwamish, discuss the history of Seattle’s relationship with its one and only river. Wagner’s writing has appeared in Scientific American, Smithsonian, Audubon and other publications. Reese is a Pulitzer Prize-nominated photojournalist recognized for his feature work and explanatory reporting during his career at The Seattle Times.

Mexico City has been featured a few times recently in the New York Times, with a focus on some of the fascinating hydrological history and its implications to modern urban life.  I was very ignorant of the specific characteristics of the city, and while I love Mexico have only had the chance to spend a long layover in Mexico City proper a few years back.  I learned much in these few articles, with a desire to dig deeper as well.

Climate Impacts

An article by Michael Kimmelman from February 17th, “Mexico City, Parched and Sinking, Faces a Water Crisis” is part of the ongoing ‘Changing Climate, Changing Cities’ series and includes a rich interactive experience, along with a compelling long form read (well worth it).

The history of Mexico City as a city has many facets, but two emerge in this context.  First is the concept that the city is built on a lake.  This map shows the configuration of the area around 500 years ago, about the time the Spanish arrived in Mexico.

Tenochtitlán, the major urban center, was established in 1325, a larger island surrounded by smaller areas islands amidst Lake Texcoco – shown as the City of Mexico below.  This aided in defense and provided agriculture using the chinampas, islands floated for growing crops.

The city was rapidly transformed via defeat and colonization:

Then the conquering Spaniards waged war against water, determined to subdue it. The Aztec system was foreign to them. They replaced the dikes and canals with streets and squares. They drained the lakes and cleared forestland, suffering flood after flood, including one that drowned the city for five straight years.

The article focuses on both this concept of geological transformation.  The second part of the story of Mexico City is the Grand Canal.  This infrastructural intervention was completed in the late 1800s, and ” a major feat of engineering and a symbol of civic pride: 29 miles long, with the ability to move tens of thousands of gallons of wastewater per second. It promised to solve the flooding and sewage problems that had plagued the city for centuries.”

The City being built on a lake has led to subsistence due to geological forces, and the need for drinking water has meant well drilling on a huge scale – both leading to elevations of the city being dramatically lowers.  This makes gravity-based infrastructure like the Grand Canal a bit problematic, as they can no longer freely drain.  The city, which occupied a metropolitan area of 30 square miles in 1950, now occupies closer to 3000 square miles, so and the almost 22 million inhabitants exert massive pressures on the land.

Some great interactive graphics from the NYT show the canal in the context of the ancient lake bed that sprawls through the region (see how this relates to the map above).

This plays out in the map below, which highlights the worst place of subsidence – the darkest red portions sinking around 9 inches per year.

[Click maps for larger views or check them out in the original article for overlay]

The problems, as mentioned, are based on some bad decision-making in urban planning back centuries ago.  This have been exacerbated by climate change – meaning lack of drinking water for many and the potential to lead to health issues, mass migrations to other cities, or conflict, which will be played out around the globe.  This example of non-coastal impacts of climate change is one of the most interesting aspects of the story, as much attention has been placed on sea-level rise but less on inland communities.  “Mexico City — high in the mountains, in the center of the country — is a glaring example. The world has a lot invested in crowded capitals like this one, with vast numbers of people, huge economies and the stability of a hemisphere at risk.”

One way this phenomenon is visible is in the architecture, with subtle rolling building forms as seen below creating waves of differential settlement.   An animation of the process shows the action creating this building form, due to differential layers of volcanic soils and clays, which drain and hold water at dramatically different rates.

What happens when the water is drawn down creates instability reflected in the constant sinking and retrofitting of buildings.  Kimmelman explains the impacts: “Buildings here can resemble Cubist drawings, with slanting windows, wavy cornices and doors that no longer align with their frames. Pedestrians trudge up hills where the once flat lake bed has given way. The cathedral in the city’s central square, known as the Zócalo, famously sunken in spots during the last century, is a kind of fun house, with a leaning chapel and a bell tower into which stone wedges were inserted during construction to act more or less like matchbooks under the leg of a wobbly cafe table.”

Aside from the quirky buildings, there are major issues throughout the region, more pressing as climate change increases.  Kimmelman mentions that “development has wiped out nearly every remaining trace of the original lakes, taxing the underground aquifers and forcing what was once a water-rich valley to import billions of gallons from far away.”  That conveyance of water is so difficult, that many residents are unable to get water easily, especially from taps.  This has led to an economy of ‘pipas’, “large trucks that deliver water from aquifers” to fill tanks.  Approximately 40% of residents get water this way.

The other issue is the difficulty of removing sewage and drainage, again because of geology and topography, along with leaks and inefficiencies of the aged infrastructure.  The Grand Canal is no longer able to gravity flow, described as “wide open, a stinking river of sewage belching methane and sulfuric acid”.  Pump stations are installed to assist this, and the canal, albeit ‘visible’ is marginalized, traveling under roadways and being polluted via impervious surfaces along the way.

While portions of the Grand Canal are still visible, the hidden hydrology and it’s implications, heightened by climate change, are evident in sinking buildings, lack of drinking water, and substandard infrastructure, a trifecta of issues that come back to the origins of a water based city from seven centuries back.  I mention long history, and this is a lesson in how quickly the decisions of the past can turn on us with population growth and a changing climate.

Per Kimmelman: “The whole city occupies what was once a network of lakes. In 1325, the Aztecs established their capital, Tenochtitlán, on an island. Over time, they expanded the city with landfill and planted crops on floating gardens called chinampas, plots of arable soil created from wattle and sediment. The lakes provided the Aztecs with a line of defense, the chinampas with sustenance. The idea: Live with nature.” 

The idea at the time, and even today is valid, but the modern challenge is confirmed by Loreta Castro Reguera, “a young, Harvard-trained architect who has made a specialty of the sinking ground in Mexico City, a phenomenon known as subsidence” who was interviewed in the article.

““The Aztecs managed. But they had 300,000 people. We now have 21 million.”

Xochimilco

A follow up from features the further story of the hydrology of Xochimilco, a UNESCO World Heritage Site that was covered by Victoria Burnett in a February 22nd story “An Aquatic Paradise in Mexico, Pushed to the Edge of Extinction” This article picks up the thread of the canals and islands from the original settlement.  “With their gray-green waters and blue herons, the canals and island farms of Xochimilco in southern Mexico City are all that remain of the extensive network of shimmering waterways that so awed Spanish invaders when they arrived here 500 years ago.”

The article focuses on the impacts of water usage in the region, with water from Xochimilco being pumped to other areas of the city, creating sink holes and draining canals which threaten the livelihoods of farmers and tourism industries.   The canals have long supported both industries, and also include wetlands and the infamous farming techniques called chinampas, which date back to Aztec era, and include ‘floating gardens’ in the shallow lakes.  A photo of these from 1912 show the this in action:

The article discusses the residual impacts of development on the aquifers, which impacts the regions waterways, but also, similar to the previous article, creates subsidence that impacts buildings and sinkholes.  The visible whirlpool in January lowered the water level quick enough to cause alarm before it could be stopped.

The water tourism in the area, typified by the trajineras, a blinged out local gondola, has been impacted as well.  One of the operators takes heed of the omens of water, stating:

“Nature is making us pay for what we have done”

In additional to development (building on the chinampas), there is pollution of the canals themselves, which has jump-started some efforts to reduce water use of the aquifer through rainwater harvesting, but the immensity of the problem of supplying water for a region with 22 million people is massive.  The balance between providing water and maintaining the cultural heritage means the possible loss of knowledge of chinampa farming, as well as health issues for locals.  This could quickly become irreversible, unless action is taken, as mentioned by Dr. María Guadalupe Figueroa, a biologist at Autonomous Metropolitan University, who ends the article: “…without a serious conservation effort, the canals will be gone in 10 to 15 years. But much of the damage was reversible, she said, adding: “It’s still a little paradise.”

Invisible Rivers

The two articles reminded me of a couple of articles I had filed away for future posts.  With the interest piqued from the above coverage, I dove into a 2016 CityLab post “Mexico City’s Invisible Rivers” which focuses on the work of Taller 13 and their plans to “uncover the 45 rivers that flow under the Aztec capital, hidden underground for decades.”  The first phase involves the Piedad River, and the idea of daylighting 9.3 miles of the corridor. shown in some detail below (with many more images on their site via the link above or via an online document here).

There’s a lot of similarity to the Cheonggyecheon River in Seoul (mentioned here in the Lost Rivers documentary post) in terms of the final look and feel as well as the transformative potential, as mentioned in the article by urban biologist Delfín Montañana”

““This project shatters paradigms. It proposes to tear down a private road, which you cannot use unless you have a car. What we propose is that we remove the cars, open the pipes, and treat the water. We need to transform the model of our city”

The hidden gem in the post is the document “La Ciudad de México 1952 1964” published by the Departamento del Distrito Federal. México,  This document outlines the public services of the city, including chapters on water and sewer that have some great info (with, in my case, some translation).

Sections on potable water and drainage show ‘modernization’ along with maps of these systems (of passable by not great quality).  The following shows the drainage system of the time, which involved a lot of pipes and images of pipes being built, and people in pipes.

A colored map of the historic Mexico from the document takes us full circle, to the hydrological history, a city literally built on a lake, economies as well built on that watery foundation, and now dealing with the consequences.

Map-making is an inherently iterative process.  Often finding an appropriate base layer is vital to providing a solid foundation for this process. In this spirit, I’ve been working on the digitization of the basic Public Land Survey System (PLSS), or the Cadastral Map series for both Portland and Seattle from the 1850s as base maps for the hidden hydrology studies of both cities.  This data, which is the most uniform and complete snapshot of the landscape of the west, is a great resource for the locations of historic streams and other features.  Because the use of the shared cartography of Townships with their corresponding Section grids, the PLSS maps provides a link to very accurately georeference the historic with the modern.  Prior to diving into some of this work, I thought it prudent to discuss the Public Lands maps themselves.

There’s plenty of history out there for those in the mood, and my plan isn’t a deep dive, but more of some context.  A good starting place is ‘The National Map’ page by the USGS on the subject of the PLSS, and a brief history page from the BLM.  Everything else you may want to know about the Cadastral Survey is found at the Bureau of Land Management page of Tools, including the massive 1983 History of the Rectangular Survey System by C.A. White (46mb PDF).  The terminology of the PLSS, is somewhat synonymous with the concept of Cadastral Survey, although in reality there is a difference, as one (PLSS) is the thing itself mapping the United States, and the other (Cadastral) a type of survey, defined as “having to do with the boundaries of land parcels.”  Cadastral surveys of all types are done all over the world, and the origin comes from the “…Latin base term Cadastre referring to a registry of lands. So actually Cadastral Surveying is surveying having to do with determining and defining land ownership and boundaries” (via Cadastral Survey).  

After the Revolutionary War, there was huge amounts of available land, and the need to distribute and sell tracts became necessary for the new survey.  While the original colonies were laid out pre-PLSS using more traditional metes and bounds, but due to the immensity of the effort, Thomas Jefferson proposed a system of surveying massive open tracts of land. The Land Ordinance of 1785 set up the system and the subsequent 1787 Northwest Ordinance kick-started the process (although it referred to the areas NW of the colonies, not the actual NW Territories).

The surveying moved across the country over the next hundred years – as   The extent of the surveying is captured in the map below, starting in Ohio and Florida on the east and encompassing the majority of the midwest, plains, and west including Alaska (which is still being surveyed today), with the only exception being Texas.  Almost 1.5 billion acres were included.

Anyone who has looked at a survey will be familiar with the language of the PLSS.  Any legal land description could be generated starting with “…the State, Principal Meridian name, Township and Range designations with directions, and the section number”. There are many versions of this diagram out there, but it breaks down the foundations of the PLSS using the Principal Meridians and Base Lines, and breaking the grid into Townships and the 36 smaller Sections.

The markers are vital to maintaining the integrity of the grid over centuries, and there are approximately 2.6 million section corners across the US. An interesting link to the ‘Corner Identification and Markings’ shows some of the layout specifics and one of the common protection measures employed for the corner monuments, circling the monument in a circle of stone.  There is a shared geography continuity between the principal Willamette Meridian, established in 1851, with bisects both Portland and Seattle, and the shared baseline which runs parallel a bit south of the border between the two states.

In the Pacific Northwest, and there’s some reverence for the particular.  The Principal Meridian Project is pretty fun, and has some great photos of the Initial Point (the crossing of the Principal Meridian and the Base Line seen above), found in  Willamette Stone State Heritage Site in Portland.

“The Willamette Meridian was established June 4th, 1851 and runs from the Canadian border to the northern border of California. The base line runs from the Pacific Ocean to the Idaho border. All property in Washington and Oregon is referenced to this point.  The original stake was replaced by a large stone in 1855 and is now part of The Willamette Stone Park in Portland.”

The PLSS is still updated, so if you want a deep dive in this topic, you can reference, the 1973 Manual of Surveying Instructions , which provides the most current info on PLSS surveying.  Rather than a mere history lesson, the concept of the PLSS is vital to the understanding the ability to reference historical maps and .  This is less important for East Coast but for a large portion of the United States, is the vital tool for hidden hydrology work.  Also the extent of coverage that was all completed within a short timeframe (at least in local areas) provides a measure of comparability between areas.

A typical survey map shows the detail of the maps, in this case Township No. 1 N. Range No. 1 East, in the Willamette Meridian, with downtown Portland in the bottom of the map, and showing some of the topographic features, ponds, and streams.  IN this case, the original 1852 map was redrawn in the early 1900s, which is pretty common.  This info is downloadable via the BLM site.

And the typical surveyor notes, which are a tough read, but shows the information which was later interpreted by the mapmakers, based on the surveyors notations as they followed the specific section lines within the individual townships.  The interpretation is a key item that implies the ‘filling in the blanks’ of these maps, as each line was not individually surveyed.

To see this in action, and to explain the correlation between georeferenced history maps and the modern GIS, you see the rectangular areas of the map Sections (this map is a composite of the map above (T01sn01e) and the Township below (T01s01e).  This is the area in the Taggart neighborhood, in this case the upper Taggart Basin, showing the Willamette River (light blue), some small water bodies and streams (darker blue), as well as riparian wetlands (green).

The same area is georeferenced with modern GIS info (in this case the 2010 roads, parks, schools), and you can see the Section Lines (orange) that register on maps.  The Taggart streams have long been buried, along with the filling of the wetlands along the Willamette for industrial lands.  The modern topography is also shown, and you can see the tracings of the landscape channels still evident today.

The ability to tap into other map tools, in this case digital elevation ‘hillshade’ model (of the Lower Taggart Basin) again give some context for new and old, and graphically show some of the landform that exists today.  There’s no shortage of analysis once the PLSS info is referenced.  Lots more specific info on these maps in Portland and Seattle coming soon.

While amazingly detailed, the maps are, as mentioned, somewhat variable in nature due to the interpretation of survey notes and mapmaking.  Thus, the PLSS becomes a great starting point, with good coverage and georeferencing, some they become a framework for overlaying other maps and data.  Also, while the surveying standards were the same, as I will point out in a future posts, the quality and legibility of the maps often depended on the mapmakers themselves, and maps of one location could have very different information.  This is evident from looking at Seattle versus Portland, and what i feel is a specific quality of maps in the latter versus the former.


Endnote:  Having grown up in North Dakota, I was very aware both of the grid, and the ubiquitous grid-shift – as the rhythm of gravel roads cut through the state if perhaps more evident and legible when each ‘back road’ follows a grid.  The excerpt below from Fathom shows the amount of contiguous one miles squares.

This making it infinitely possible to chart one’s path multiple ways to get to locations, and also comes with long stretches of arrow-straight road ending with a curve or more often a tee.  Many a speeding or slightly inebriated driver was been surprised by this phenomenon.   This comes up perusing such Instagram accounts like The Jefferson Grid, and for me more recently someone linked to re-posted from an article in Hyperallergic, featuring work of artist Gerco de Ruijter from 2015, as he masterfully documents this using a series of Google Earth images.

From his site:

“By superimposing a rectangular grid on the earth surface, a grid built from exact square miles, the spherical deviations have to be fixed. After all, the grid has only two dimensions.  The north-south boundaries in the grid are on the lines of longitude, which converge to the north. The roads that follow these boundaries must dogleg every twenty-four miles to counter the diminishing distances: Grid Corrections”

For more on this, check out Geoff Manaugh’s post from a few years back and his longer article in Travel & Leisure magazine.  And for a bit of bonus, check out Gerco de Ruijter short video ‘Grid Corrections’ (i prefer with the sound off, but let me know).

Grid Corrections (a one minute) from Gerco de Ruijter on Vimeo.

HEADER IMAGE:  Archival Photo of Surveyor – via BLM

The recent post Aquae Urbis Romae discussed the Waters of Rome project by Katherine Rinne.  As mentioned, the map referenced most heavily in her work is the 1551 Bufalini map, which shows conceptual topography and figure ground relationship. Like anything, once you dive into the maps of a particular area, especially one with the history, you can quickly fall down the rabbit hole.  So dive in.

A great article from The Metropolitan Museum of Art, Antonio Tempesta’s View of Rome: Portraying the Baroque Splendor of the Eternal City links to a number of maps that were created as part of a 2012 Bernini show.  Chronologically, this Nicolas Beatrizet engraving from 1557 is around the same time frame as the Bufalini map, but simplified, with some interesting graphic style and axonometric illustrations:

A more aerial version of this perspective from the west in 1590 is found in the Speculum Romanae Magnificentiae: View of Modern Rome from the West by Giovanni Ambrogio Brambilla.

The map perspective ‘Plan of the City of Rome’ from Antonio Tempesta is from 1645 but was first printed in 1593 around the same time as the Brambilla map, bust showing the view from the northwest.

The maps as a whole is broken into twelve tiles, so zooming in on an individual view shows the richness of the illustration.

Taking a similar view from the Northwest as the Tempesta map, Matthuas Merian’s 1642 Topographia Germaniae printed a color version, showing the view in 1641, and definitely highlights how the use of color can change the nature of a map.

Coming 200 years after Bufalini, the (argubly) most famous map of Rome is one of my favorites, the 1748 Map ‘Grande Pianta‘ by Giambattista Nolli (more commonly known as the Nolli map).  This work of art is infamous for its detail and being the precursor of the expanded ‘figure-ground’ diagram many of us use today.

Nolli Map – via visual.ly

A set of high-resolution tiles from UC Berkeley allows for zooming in to the beauty of the map, the gradations and the figure-ground representation.

The idea of the interior public spaces as ‘void’ on the map is worth a close-up, as you can see above a bit, but it’s easier to read here, where you can see the plaza spaces (bottom of Piazza Navona on the upper left) versus the interior spaces such as the circular Pantheon and the structure of local churches:

And I love the way some of the gardens are represented, which gives a somewhat different feel from plaza spaces – sort of creating a spatial hierarchy and network of green spaces.

After searching, I found the term for the illustrative border, not sure if that’s the cartographic term, but the veduta ‘italian for view’ is typically a cityscape.  The one the Nolli map illustration was done by Stefano Pozzi.

There are some other high resolution version of this as well, and if you have the means, they can be purchased here, here and here.

For the interactive options, a project of University of Oregon spawned an online interactive version of the Nolli Map“The Nolli website presents the 1748 Nolli Map of Rome as a dynamic, interactive, hands-on tool in both written and graphical form. The map not only provides rich information, but it has the ability to be updated with new data over time to embrace expanding knowledge.”  The viewer is ok, and the thematic symbols are interesting, but resolution is a bit too small, objects aren’t clickable and the interface is somewhat hard to navigate.  

For some other options, there’s an OS app as and another digital version from B-Open Solutions which is a simple georectified copy overlaid on the modern map, allowing for easy zoom, multiple underlays, and opacity shift to see the before and after (which amazingly is not that different – owing to the quality of Nolli’s map-making).  It also includes the ability to click on the original legend for Nolli’s map.

 

The Nolli map is the touchstone of modern mapping in Rome. In the mid 1800s, for some reason, an almost exact copy of the Nolli map by Paul-Marie Letarouilly. A clickable version of a tourist map based on the 1852 map is the basis for a clickable map of info by Rome Art Lover, which has some good info (lurking within a mid-90s website style).  More interesting is his precursor, which is also based on Nolli, the  1849 Plan de Rome Moderne au tiers de celui de Nolli which acknowledges the original.

Detail shows the homage to the interior public spaces from Nolli, and something about the sparseness of linework (albeit a copy) makes this a beautiful addition to the map library .

CODA: DEEP HISTORY

As I emerge from the rabbit hole, it reminds me of the rich history of mapping, and the skill of the mapmakers in the absence of modern tools.  While this is not about hidden hydrology per se, the map as a tool, inspiration, and guide is a thread that permeates mine and others interest, and the concept of multiple maps documenting ‘long’ history is impressive.   In that spirit (inspirations and rabbit holes) one must go even farther back, and visit the Stanford Digital Forma Urbis Romae Project, which documents the Severan Marble Plan of Rome.  Be forewarned, you can lose yourself in this one.  Some background:

“This enormous map, measuring ca. 18.10 x 13 meters (ca. 60 x 43 feet), was carved between 203-211 CE and covered an entire wall inside the Templum Pacis in Rome. It depicted the groundplan of every architectural feature in the ancient city, from large public monuments to small shops, rooms, and even staircases”

There are available a little over 1000 fragments, many with few marks and some painting the rich historical story of the map.

To give an indication of the immensity of the effort, some more from the site, “The Severan Marble Plan is a key resource for the study of ancient Rome, but only 10-15% of the map survives, broken into 1,186 pieces. For centuries, scholars have tried to match the fragments and reconstruct this great puzzle, but progress is slow–the marble pieces are heavy, unwieldy, and not easily accessible. Now, computer scientists and archaeologists at Stanford are employing digital technologies to try to reconstruct the map.” 

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From the recent post, Indeterminate Rivers the Geological Investigation of the Alluvial Valley of the Lower Mississippi River by Harold N. Fisk offers a wealth of information on landscape change.  When I first saw the series of maps the idea of showing the shifting path of the river came to mind – and I envision a much more intensive and animated idea could be applied to the color map series (from the original post) to illuminate not just the static traces but the actions of this hidden hydrology over time.

The simple animation below is based on the maps in the report that discuss the formation of the valley and the current configuration of the meanders.  For reference, this map isn’t an attempt to make  conclusions, but to activate some of the data represented in 2-D format in the report – showing the breadth of change of the main path of the Mississippi over the course of 4000 years of change.

More explanation of the specifics found at the page ‘Mississippi River Change’.

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The concept of history is relative. Living in the Pacific Northwest in the United States, a span of a few hundred years constitutes the sum of contemporary settlement and European colonization (with some exceptions). Many contemporary cities such as Seattle and Portland, for instance, were only formally settled in the 1850s, are were not urbanized for decades after, resulting in relatively short histories. Obviously these lands were populated for years previously by indigenous peoples, some with formal and informal settlements, however, either way, the modern urban form is young.

The eastern US has a slightly longer history, but even New York’s history of European settlement dates around 1600, so around four-hundred plus years.  Many places in the world have a much different story and measure history is very different terms.  Rome, for instance, offers a different scale of time, much deeper picture of history spanning millennia.  Depending on who you consult, Rome was a village since the 9th Century BC and became a city around 753 BC, so has been evolving for almost 3,000 years.  In much of this span “The Roman empire stretched over three continents, had 70 million people, and had a logistics and infrastructure system that kept them going for centuries.”  (via Science 2.0)

A great site to explore this immense history with a unique focus on water is Aquae Urbis Romae: The Waters of the City of Rome – a long-term project of Katherine Wentworth Rinne from 1998 to present, which is published by the Institute for Advanced Technology in the Humanities from University of Virginia.

A summary:  “Aquae Urbis Romae is an interactive cartographic history of the relationships between hydrological and hydraulic systems and their impact on the urban development of Rome, Italy. Our study begins in 753 BC and will ultimately extend to the present day. We examine the intersections between natural  systems–springs, rain, streams, marshes, and the Tiber River–and constructed systems including aqueducts, fountains, sewers, bridges, conduits, etc., that together create the water infrastructure of Rome.”

The site has a ton of information, especially great for an Italophile such as myself.  The content is organized into a few categories, some of which are for archival purposes as their web presence is not longer functional, but there is info organized as a timeline (including a GIS Timeline Map), as well as by typology, and studies of topography.  There are maps and a list of resources and some good primary and secondart texts available.  The journal “The Waters of Rome” offers ten essays with some additional scholarship on Rome history and culture around water.  I’ve yet to dive in depth into these, but look forward to it.

For hidden hydrology perspective, the Timeline features the ability to isolate typologies that allow focused look at systems.   A section of maps on Hydrological Setting, shows the hidden streams overlaid on modern (c. 1998) city grid and topography.  “This map represents a composite of data drawn from archaeological, geological, historical, and literary evidence concerning the hydrological structure of the intramural city and its immediate surroundings. It does not represent a specific point in time, but rather represents an amalgam of hydrological features, most of which have been known since antiquity. However, water is dynamic and therefore constantly changing. Springs can disappear, dry up entirely, or reemerge at a different, sometimes distant location. Streams and rivers can change course, and the profiles of their beds are constantly changing as well.”

This information is activated by translation into three-dimensional views in the Topography section, providing some more info on the landform that relates to historical streams.  They are developed thematically as well, with a number of studies such as hydrology and aqueducts serving the baths and fountains in the city.

Today this is somewhat simplistic in terms of graphics. In 1998, this would have been pretty cutting edge stuff.  Similarly, the GIS Timeline map offers both spatial and temporal info in a more interactive format, with the ability to customize.  This is the best info I’ve found on historical hydrology of Rome, via the Geographic features typology that include Marshes, Swamps, Rivers, Streams, and Springs, a few of which are plotted below.

The focus is on water, but not just streams, there’s a range of other typologies, including water distribution, infrastructure, flooding, markets, walls, neighborhoods (rione), baths, fountains, and more.  The icon based map allows for more info via pop-ups.

A legend shows the span on types of info captured, along translation of English and Italian terms.

The temporal aspect is a interesting idea, as it allows a fourth dimension to the mapping that seems vital to historical study. The slider (seen below) allows for all years to be selected, or to select individual decades, and eras, to capture snapshots of info at certain time frames.  As mentioned on the site: “Follow the urban development of Rome through a unique G.I.S. timeline map that chronicles changes to the water infrastructure system from 753 BC through the sixteenth century. See how sewers, aqueducts, fountains and other hydraulic elements changed the face of Rome, as important people like Agrippa, Emperor Nero and popes Sixtus V and Clement VIII, among others, used water as an element of political control.”

This obviously works better for cultural features like buildings and fountains that have specific dates of creation and erasure, so not sure if it captures erasure of surface streams into subsurface routes.  However, with enough information, you could show the disappearance over time for any water system and include animations at a time step (similar to this historical study of the Mississippi River gleaned from the Fisk maps).  Something worthy of exploring with current GIS and animation technologies.

The site is plagued with some old technology in terms of web design (frames, for instance, which are awful for navigation), as well as the mapping and animations discussed above. This is tough, as its always hard to keep things up to date.  Over time, something using the most recent tech quickly becomes outdated, especially on a project that spans decades such as this.  That said, the content holds up very well, and some easy fixes would be to remove some of the clunky old maps and convert these to simpler embedded open source interfaces (Google Earth, etc) – as well as to be able to download GIS files of some of the key info. Sounds like from some of the notes, there’s some updates in the works, so look forward to reaching out to Ms. Rinne and see what she has planned.

The idea of deep history in tied closely with the maps, and the long history of mapping Rome is a fascinating rabbit hole to dive into.  The site offers a link to many Print, Drawing, Map and Photographic collections of Rome, where you will find the the key source in this exploration, the map ‘Roma’ by Leonardo Bufalini in 1551, which shows a somewhat developed city plan along with rudimentary topography and hydrology from almost 600 years ago.

The site offers each of the tiles of the map, (noted: Courtesy of Kersu Dalal, Johnson Fain Partners, Los Angeles).  This shows a lot of amazing detail, and hints at slopes and ridges and depressions that impact water movement.

A figure from the 1897 publication “The ruins and excavations of ancient Rome” by Rodolfo Lanciani shows the ‘Hydrography & Chorography of Anicient Rome’, capturing many of the streams and marshes shown on other maps.

And zooming about a bit, showing the broader area of “The Tiber & Its Tributaries” by Strother Smith from 1877.

The most famous map of Rome is one of my favorites, not mentioned much on this site, but well known.  Almost 200 years after the Buffalini map, the 1748 Map ‘Grande Pianta‘ by Giambattista Nolli (more commonly known as the Nolli map).  This work of art is infamous for it’s detail and unique showcasing of public/private spaces inside and outside of buildings, versus pure figure-ground relationships.  I’ll discuss this map and a few others from Rome in a follow-up post.

Nolli Map – via visual.ly

Images on this post from the site Aquae Urbis Romae: The Waters of the City of Rome unless otherwise noted.
Header image: Castel San’t Angelo from the South, painted in the 1690s by Caspar Andriaans van Wittel

The recent post about the Mississippi River change illustrated in the Fisk maps reminded me of this lovely lidar image of the Willamette River, which encompasses the region around Portland, Oregon and south.  The image Willamette River Historical Stream Channels, Oregon, 17 x 38 inches, by Daniel E. Coe (via the State of Oregon Department of Geology and Mineral Industries – DOGAMI).  From their site:

This lidar-derived digital elevation model of the Willamette River displays a 50-foot elevation range, from low elevations (displayed in white) fading to higher elevations (displayed in dark blue). This visually replaces the relatively flat landscape of the valley floor with vivid historical channels, showing the dynamic movements the river has made in recent millennia. This segment of the Willamette River flows past Albany near the bottom of the image northward to the communities of Monmouth and Independence at the top. Near the center, the Luckiamute River flows into the Willamette from the left, and the Santiam River flows in from the right. Lidar imagery by Daniel E. Coe.”

Via an article in the Oregonian, the utility of LIDAR in evaluating subtle changes that wouldn’t be visible via aerial photography is evident, and the “Lidar data is collected by low-, slow-flying aircraft with equipment that shoots millions of laser points to the ground. When the data is studied, an amazingly accurate model of the ground can be mapped.  It is possible to strip buildings and vegetation from the images, so that only the ground is shown. In the Willamette River poster, the shades of white and blue show elevations. The purest white color is the baseline, (the zero point, at the lowest point near Independence on the upper part of the image). The darkest blue is 50 feet (or higher) than the baseline.  The shades of white show changes in elevation, between 0 to 50 feet. This brings out the changes made by the river channel in the last 12,000 to 15,000 years, in the time since the landscape was basically swept clean by the Missoula floods.”

The evocative image that is fluid and abstracted, as mentioned in the Oregonian article by the mapmaker, Dan Coe:

“The different movements of the river make the image take a liquid shape, even almost like a cloud of smoke. This shows the magic of lidar.”

You can download high resolution PDF of this map (52.3 MB) from the site for printing.  As an added bonus, their site offers a number of interesting Oregon maps for download, including this oblique view of the Willamette River in postcard and poster formats.

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The concept of indeterminacy is built into any study of hydrology, whether contemporary or historical.  Rivers, creeks, streams are in constant, dynamic flux with varying levels of human influence from relatively pristine to the buried, channeled and culverted forms that are often our focus on this site.  The term, obviously means ‘not determinate’, but elaborating somewhat in simple terms via Webster, is “not precisely fixed in extent; indefinite; uncertain” or via the OEDNot exactly known, established, or defined“. 

The idea of looking at historical maps to unlock the stories embedded is further complicated by this variation of time, as maps represent a fixed point in time but are not a specific known entity.  This happens in many cycles, including daily, tidal, and also seasonal variations, but over time, this accumulated energy creates meanders that snake across the floodplains driven only by hydraulic rules and adjacent land characteristics.  Less dynamic rivers or streams may maintain fidelity over time, while highly dynamic streams can move.

There have been some interesting aerial versions of stream change via the recently launched Google Timelapse, however, my go-to for visualizing indeterminate river are the Harold N. Fisk’s 1944 study of Geological Investigation of the Alluvial Valley of the Lower Mississippi River.  Fisk was a Professor of Geology at Louisiana State University. Known as the Fisk Maps, these made the rounds of landscape and mapping blogs over the past decade, blowing people away with both their complexity and artistry.

The ability to use two-dimensional graphic techniques to represent temporal change is the subject of much discussion in visualization and landscape urbanism circles, to name a few, and these maps are often held up as positive examples of showing dynamic processes.  A wealth of information is found on the US Army Corps of Engineers’ site for the Lower Mississippi Valley Engineering Geology Mapping Program including the full report, large format.  [Note: these files are large so I’m not directly linking to the zip files direct – so follow the link above]

The expanse of the Lower Mississippi alluvial valley drainage shows how much movement the river on it’s 600 mile journey through the Central Gulf Coastal Plan from southern Missouri to the Gulf of Mexico a massive delta landscape that has been massively altered by natural and human processes for decades, showing that even with our technological advances, the river often still doesn’t obey our wishes.  [Aside: For some great reading on this, check out McPhee’s ‘The Control of Nature’, one of the best on the topic]

The idea of dynamism is key and the study of this change over time offers an interesting dilemma.  The ever changing paths of meanders are able to be mapped in modern times, but previous paths require understanding geologic cues to trace that which had not been mapped.  The black and white maps show the overlay of dashed meanders with aerial photography, which in the mid 1940s, was not new, but was still a relatively nascent planning technology, albeit rapidly expanding due to advances in World War II.   It will be interested now with accessible tools like Google Earth and the constant documentation of detailed aerial and satellite imagery to see how a study like this would be done today.  This map below is one of the figures in Fisk’s report, showing dramatic changes of a section of the river at a historic ‘Diversion Point’

The main report has predominately black-and-white imagery, probably due to reproduction costs in the 40s, but they still hold up.  Any who has read a geotechnical report knows many of the techniques for representation of borings and soil strata know they can sometimes be a bit try and technical.  This report is somewhat dense (and to be honest I’ve only skimmed some parts) but the visuals are so compelling.

Large, multi-page pull outs of regional geologic sections remind me of the early figures of von Humboldt, which contrary to more modern interpretations had a certain life to them.

Even the meander diagrams (in this case showing uses of clay plugs to control river bend migrations) are pretty cool in black and white.

Similarly, detail diagrams of braided stream topography and floodplain deposition are works of art, while also attempting to communicate immense amounts of technical information.

My hidden gem here is this graphic table of Geologic Time which traces Eras base a billion years and overlays the idea of big time with the relative amount of our recent human history.  I’m pretty sure I’ve seen this reproduced in modern geotech reports, or somewhere, but there’s something about serious report containing imagery of cave-people and dinosaurs to put the breadth of time in perspective.

Anyone who’s attempted to communicate using black and white figures knows they are tough to pull off graphically.  The above examples show that there’s a lot of information that can be conveyed in simple linework and that it doesn’t need to feel static.  That said, the beauty of the Fisk maps are the dynamic color plates, easily highlighting change and dynamic processes. A representive full map below shows the interplay of linework, hatching and color to bring the technical information to life.

A close up of a different map, showing the immense amount of information in meanders, oxbows, eddies, and the extensive floodplain of this massive river system.

The legend shows the color coding scheme based on when the rivers were mapped (solid) and those dervied from clues via aerial photograph analysis (hatches).

The entirety of the set of meander maps (that were rectified) has been stitched together – and is sort of incredible, via a Nerdist post from 2014.  I’d love to print out these full size and display somewhere.

These meander maps are a next iteration of earlier mapping, derived from a series of Stream Channel maps from 1939 (also available via the LMV Mapping page) that show the most recent survey work (when I say recent I mean 1700s to early 1900s.  It’s  still impressive (and a bit simplified) to see the amount of channel change.  Not sure if Fisk was involved in these maps, as they predated his involvement in the final report, but there’s similarities in graphic style and content.

While the maps of the meanders get much of press, I’m also a big fan of the Stream Courses (these are also part of the Fisk report, downloadable as plates via LMV Mapping page) which are larger maps showing multiple, color-coded maps of stream change over the past 2-3000 years.  One of the maps below shows a section of the main step and remainder of the valley.

The key gives some idea of the way time is juxtaposed spatially on the map.

You can pinpoint the specific stream courses and alluvium in an enlargement, telling another complex story of river movement.

The reports and links abound with interesting information, such as the Entrenched Valley System, which delineates a dendritic network which contains the main channels and tributaries of the Lower Mississippi basin.  This visual technique is somewhat more topographic, hinting at the tracery of valley to upland and basin shape that would be visible, and perhaps offered some resistance to channel migration over time.

This entrenched valley structure is shown in larger context, as the main stem outfall potentially being directed towards a real hidden river – a “submarine canyon” in the Gulf of Mexico.  I’d be curious if that is the actual hydrology based on our current knowledge, but I’d not thought of subsurface hydrological flow influencing river systems (although in retrospect it makes perfect sense).

Some other interesting maps that tie in basin and river specific info are accessed via main LMV Mapping page.  These show geological investigations and Alluvial Deposits throughout all of the basins.  Clicking on a basin will get you to specific 15 minute quadrangle maps, selectable within the study area.

The maps show distribution of alluvial deposits, which is less about channelization than the overall reach of the floodplain hydrology.  The difference between low-lying Baton Rouge, for instance with a wide flat deposits.

… contrasted with a more northern location, Caruthersville, Missouri which shows a long series of bends and oxbows left over time.

I also love the annotated sections showing strata via geological investigation, in this figure for Caruthersville highlighting predominate soil types.

SUMMARY

As mentioned, the idea of indeterminacy is writ large in the study of hidden hydrology as it connects historical ecology to the modern metropolis.  History is a series of touchstones over time, and the information we have is always incomplete, requiring us to interpret the data points we have and make inferences to that which exists in the gaps of knowledge.  If we are to use the historical maps and sources we must understand this process (and perils and pitfalls) and be respectful of what we know and that which we can never know. Indeterminacy, as with life, is the heart of these explorations.

The work of Fisk on these maps is also a great example of looking back in time at a dynamic system and unlocking the story in visual terms.  The visualization challenges can be addressed in a number of ways, and technologies of visualization exist today that our predecessors didn’t have, but also show that we don’t need to rely on too much technology to tell a vibrant story – a pen and paper, perhaps some color, as proven above, can tell many tales.

 

 

 

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As outlined in my previous post, the San Francisco Bay Area is loaded with many hidden hydrology focused activities and groups working throughout the region.  This follow-up post will address the amazing depth of resources available for historical maps and other resources for mapping and exploring lost rivers and buried creeks in the bay area.

The first place to look would be the amazing Guide to San Francisco Bay Area Creeks, which has an amazing array of creek maps covering the entire region, published by the Oakland Museum of California, many of which were also funded by the California State Water Resources Control Board and U.S. Army Corps of Engineers. You can select maps or use a sort of useful Graphic Creek and Watershed Finder to select areas via map.

The site itself isn’t just a portal to information, but includes a lot of maps, historical and contemporary as well as supporting info like Creek’Zine with stories of local history, or a glossary of creek and watershed terms.   Each map page offers links to the many creeks either through text or clickable smaller basin maps, like San Francisco.

This scaling linking allows for easy drilling down to subwatersheds, for instance to Islais Creek Watershed in San Francisco. you find more info and specific clickable elements,

Clicking on the map triangles yields more info – ostensibly what is found on the full printed map, but it’s nice to have really easy access to this online, in some depth.  An example is found in the link to Glen Canyon:

The key shows the depth of information available, including the basins, man-made and natural drainage infrastructure, waterbodies, fill and other structures.The sidebar has keyed Historical Features, circa 1850 including ‘Creeks, buried or drained’, ‘Ephemeral creeks’ and areas that were filled.

Each map page also links to a number of historic or descriptive maps that outline water systems, topography or juxtapose the new and the old.  For Islais Creek, above, a 1896 USGS Topographic map shows some source materials and evolution of the area prior to filling the historical features.

The main excerpt maps are zoomed in versions of the larger printed maps, which are pretty dramatic (in their digital form).  This one showing Oakland and Berkeley areas in the East Bay.   “The printed version of this map presents both the historical and modern hydroscapes of the western drainages of Northern Alameda County.”

I can stare at these for hours even though I don’t live there, that’s how fascinating they are.  Click on the map to download a PDF, (3.0 MB)

An excerpt shows the detail (in this case around Lake Merritt) which is pretty representative of the maps.

I’m still amazed at the coverage of these maps, and although some are getting old, the overlay info should still be pretty accurate even in the boom of development and redevelopment happening in the area.  There are maps for purchase and download, along with some GIS and KMZ files for further mapmaking opportunities.  As San Francisco proper is (mysteriously?) the only version of the PDF map not downloadable, I purchased a few of the printed maps so will see how they look when they arrive in early January.

As an added bonus, I really liked this animated map showing San Francisco in 1869 and 2007. (will launch in new tab for a bigger version).  This shows a simple evolution of the entire city, rotating through 150 years of change.  A dramatic difference, I’d say.

An additional find was the Guide to East Bay Creeks, a brief series of essays by Sarah Pollock, Shelby Hall & Christopher Richard.  Now only available online, which includes narratives for the specific hydrological and ecology – sort of a regionally specific creeks 101.  From the intro:

“Throughout the East Bay city dwellers are recognizing that even in urban areas we have wildlands valuable to humans and other animals. These people are learning ecological relationships through direct experience, and they are hoping that ultimately there may be an attitude shift, a cultural recognition that even city dwellers are an integral part of a living system.”

The previously mentioned San Francisco Estuary Institute, which was responsible for some of the maps available above at the Guide to San Francisco Bay Area Creeks, and is a wealth of information on their site, both in terms of research reports but also GIS information. In their Data Center, you can search for tools, services, visualizations and other resources applicable to resilience and historical ecology among other topics.  Their work extends throughout the region, but has many overlaps in the Bay Area, including the GIS data for the Alameda Creek Historical Ecology study mentioned in the previous post, and rich data sets such as The San Francisco Bay Shore Inventory: Mapping for Sea Level Rise dataset provides a comprehensive and consistent picture of today’s Bay shore (up to MHHW + 10ft) for all nine Bay Area counties.  These data are available in ESRI ArcGIS file geodatabase and Google Earth KMZ format.”

Building on the last study, the SFEI folks also had a link to an awesome Historical Ecology resource, the online viewer for U.S. Coast Survey Maps of SF Bay, which provides maps of shoreline “Under the direction of some of the leading American scientists of the 19th-century, the USCS created exceptionally accurate and detailed maps of the country’s coastline. In the San Francisco Bay Area, these surveys (commonly referred to as “T-sheets”) are the most important data sources for understanding the physical and ecological characteristics of the Bay’s shoreline prior to Euro-American modification.”

The interface could use an update, but with a bit of digging the T-Sheets are available for download and are rotated and georeferenced, and includes raster and vector files. The image above I rotated and cropped – and you see that, aside from utility, these are some of the most beautiful maps.  Another zoomed excerpt.

I’ve dug into the T-Sheets for the Seattle area, and they are some great maps with pretty extensive coverage.  A few links provide a good tutorial, including a T-Sheet Users Guide authored by Robin Grossinger,  From their summary: “This guide discusses the historical maps of San Francisco Bay produced by the United States Coast Survey (USCS) and their application to present-day environmental efforts in the region.”

There are also Seep City maps, the project mentioned in the previous post, including print maps, atlases, and a forthcoming book available for purchase from Joel Pomerantz.  Another regional resource worth checking out is the Watching Our Watersheds – interactive mapping from the Santa Clara Valley Water District, which provides a good example of online interactive water tools using Google Earth.  Check it out and download the data at the link.

I’d be remiss without touching on some of the cool historical map sources, including a few gleaned from the Guide to San Francisco Bay Area Creeks page, including this interactive map from the 1860s

San Francisco c. 1860 – click to open in new tab
Topographic map from the 1890s with original creeks in blue, marshes in green, and modern land fill in pink

More to come as I’ve barely scratched the surface on SF Bay area and have not fully looked at historical sources other than those mentioned elsewhere.  This may be due to the amount of info available rivals most cities.  Kudos to the people at working in this region for providing inspiration and great precedents for work to apply elsewhere.

And if you haven’t yet, read the first of this series – Lost Creeks of the Bay Area – Part I to learn about the groups working in hidden hydrology, art, and urban exploration.