The ability to reveal the hidden layers of hydrology can take many forms. Public art is a great mechanism for telling stories in ways that engage and reveal that which is often missing from our day to day experiences. These artworks also highlight key contributions of communities that are often marginalized in the official histories we are taught. Artists Shu-Ju Wang and Lynn Yarne developed a vibrant example of this at the new Lincoln High School in Portland with a large exterior mural called Restoration Roadmaps which locates the hidden hydrology story within the context of the urban high school. The summary of the project, from the artist’s website for Restoration Roadmaps provides some of processes and the outcomes:

“The process enabled us to come to a final design that is a combination of several forms of maps to describe the neighborhood–from historical to a hoped for future, from topographical to ecological, from google map to the old fashioned foldout map. Student and community responses are recorded as part of the topographical contours and inset panels.”

The images are rich with detail, focusing on the high school site and the contemporary grid, juxtaposed with the Tanner Creek historical route with other water bodies that have been erased. The creek gulches were the locations of highly productive garden areas farmed by Chinese immigrants and also provided historical areas of Native American occupation. The mural includes smaller square panels with community work done by other artists and students, and the perimeter of the mural provides detailed assemblages of 40 species of flora and fauna Indigenous to the area.

Mural Image (via Shu-Ju Wang)

It was fun to see the process evolve and the final product ‘in the wild’ below. Let me know if you’re local and have seen the mural, or if there are other murals in your community celebrating hidden hydrology. Would love to hear from you.

Final Mural (via Shu Ju Wang)

HISTORICAL BACKGROUND

The lead-up to the public process included some great information compiled by a series of experts on the history, ecology, and culture around the Tanner Creek area and the Chinatown farmers. These included lectures by Dr. Tracy Prince on Native American Traders and Chinese Vegetable Gardens in the Hollows of Old Portland, and Native Americans of Old Portland, and a co-presentation Notable Women of Portland, by Prince and her daughter Zadie Schaffer, who is also a Lincoln alum. Dr. Marie Rose Wong, author of Sweet Cakes, Long Journey: The Chinatowns of Portland Oregon gave a talk on Tanner Creek and Portland’s Chinatown. Eric Butler, a restoration expert, included information on the Ecological History of Tanner Creek.

Beyond helping with some mapping for the mural, my other contribution was this short video, Tanner Creek Hidden Hydrology, walking through the history of the area in the context of the historical water. I’ve included the video below:

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Note: This post was originally posted on Substack on 02/28/25 and added to the Hidden Hydrology website on 04/20/25.

There are a number of stories that occasionally receive comments and inquiries on posts from back in the day. This past few weeks, readers reached out related to the 2017 post “San Francisco’s Hidden Water Tanks” (Hidden Hydrology, 12.15.17), inquiring about a really cool hidden feature of the urban realm.

The post drew on a great article published at the time by CityLab/Bloomberg, “The Sublime Cisterns of San Francisco” (05.01.17), which explains the presence of brick circles located at numerous intersections around the downtown core of the city, such as the image below.

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Brick circles denote the location of old cisterns (via Bloomberg)

These reference the locations of underground cisterns, dating back to the 1850s, which were state-of-the-art in fire protection in the 19th and early 20th centuries. These cisterns were distributed around the downtown area and filled with water, which supplemented fire brigades and enabled them to pump water for fire-fighting prior to implementing pressurized water systems and fire hydrants. As noted in the Bloomberg article related to the need for new modern fire protection in cities:

“One of the ways officials responded to these blazes was to build cisterns. These subterranean vitrines were designed as a last-resort source of agua for firefighting. San Francisco’s 19th-century cistern system was reinforced with more, larger cisterns after the Earthquake of 1906, whose subsequent firestorm killed roughly 3,000 and left much of the city’s land looking like a blasted moon. To date there are 170 to 200 of the tanks stashed around town.”

Many of the remaining cisterns are intact below ground, revealing subterranean spaces unknown to those walking and driving above. Many are empty, but some are still used as emergency water sources today.

Interior of cistern (via Bloomberg)

John Oram, aka the prolific Bay Area blogger Burrito Justice, dug deep into the cisterns as far back as 2011. Around 2016, when the original Bloomberg article was published, he created an interactive map (unfortunately no longer available) of their subterranean locations. The map represented the intersections where the cisterns were located, scaled by the capacity of the cistern below.

Map of cisterns by John Oram (via Bloomberg)

Another resource for these cisterns, which Oram used in his mapping project, was a 2014 project by Scott Kildall. As part of an art project called “Water Works,” Kildall focused on “…a 3D data visualization and mapping of the water infrastructure of San Francisco.” He also created an interactive map (now also unavailable) of the cisterns, and the project generated some interesting maps and art around the locations of key infrastructure, including cisterns, as seen below.

San Francisco Cisterns by Scott Kildall (via Scott Kildall)

For those interested in a deeper dive from these past sources, I recommend “What’s Underneath Those Brick Circles?” (Burrito Justice, 03.08.13), and “Cistern Mapping Project Reportback.” (Scott Kildall, 01.07.16). Although a seemingly hot topic in the mid-2010s, I only found a few scant more recent references to these cisterns. A good one worth listening to is part of a self-guided tour of these cisterns as part of the Exploratorium installation Buried History – Water Underground along with a link to a downloadable, printable map here.

I would appreciate any input from anyone in the Bay Area with up-to-date information or ongoing projects related to the cisterns.

Note: This post was originally posted on Substack on 01/31/25 and added to the Hidden Hydrology website on 04/22/25.

My first Substack publication, The Climate Landscape, explored various themes related to our changing climate and landscape architecture to examine nature-based solutions to climate change impacts. I recently decided to shelve that particular project and focus exclusively on writing about hidden hydrology; however, a few of those early essays were worth retaining here as they showed good overlap and connections between the two topics.

There is a direct connection between our cities’ buried and lost rivers and climate change. I touched on climate here in a recent “Lost Rivers for Underground Energy” and have written about it often on my older Hidden Hydrology site. It took me some time to make a direct connection between my research on climate and lost waterways until more recently, and the revelation allowed me to weave together these two passions.

I’ve continued connecting the dots and trying to build a case for the importance of historical ecology and hidden hydrology in being the locus for solutions to contemporary issues, and not just focused on nostalgia. One aspect of this is looking first at causes and effects — looking back at the erasure of waterways from cities and demonstrating that the loss of ecological and hydrological systems exacerbates climate impacts such as urban heat, flooding, and sea level rise. I also looked forward to showing the patterns of historical hydrological systems that can act as frameworks for innovative climate solutions to provide adaptation and mitigation opportunities. The idea of “hydrological retro-futures” is the term I chose for this backward-forward process, which allows us to connect the historical ecology to the modern metropolis and tell these stories in an engaging, visual format.

One aspect of this project is visual. By using various graphical generative AI resources like DALL-E (see image below), I have been creating speculative images of hidden hydrology in the urban context, and exploring ways that revealing, restoring, and reconnecting with lost rivers can help us imagine the potential visual impacts that could be gained. I will share more in-depth on this project and some of the interesting graphics in a later post.

Hydrologic Retrofutures: Portland Series 1 (Generated in DALL-E via prompts Jason King)

The other aspect is research and case-study-based. Brainstorming a few key topics areas, I will continue to explore here, including:

  • MICROCLIMATE COOLINGThe daylighted streams will restore ecosystem services lost when buried, such as the presence of cooling surface water and vegetation that can aid in mitigating urban heat islands.
  • FLOOD STORAGE CAPACITYDaylighting streams and springs currently in pipes will increase the capacity of infrastructure systems and make them more effective for flood resilience.
  • SEA LEVEL RISEAreas of made-land in cities as a proxy for areas of flooding due to SLR and storm surge and ways to adapt these to absorb with more resilience
  • WATER HARVESTING TO SUPPORT URBAN BIODIVERSITYDiversion of water that would be piped into uses for support of landscape vegetation and urban greening
  • WATER USE FOR COOLING ENVIRONMENTSTapping into water from subsurface water pipes to help cool cities – use in pools, water features, misters, etc.
  • WATER FOR HEATING & COOLING BUILDINGSUsing water from buried sewer pipes for heating buildings
  • PALEO VALLEYSLooking at hidden ancient river valleys as sources for groundwater recharge and storage as new aquifers

By exploring these topics, I aim to gather feedback and generate a complete toolkit of solutions that can provide designers, planners, and policy-makers with options that work in multiple climates and scales and provide cascading benefits when implemented. I’d be interested to know of other topics and solution areas out there beyond this list, as well as any case studies, writings, or research on these topics.

Below are a handful of previous stories that cover some of these topics.


ANCIENT WATERWAYS FOR COOLING CITIES

A recent article in Fast Company outlines the idea of “How ancient waterways could be tapped to cool scorching cities”. The focus is on new scanning methods to reveal buried streams and ‘ancient waterways’ and how to see the hidden infrastructure and potentially repurpose the water for climate change adaptation strategies. The group leading this effort is Cool City, an offshoot of the Korean Pavilion as part of the 2021 Venice Biennale, with projects using mapping underway in both Naples and Seoul. The unique idea here is to use handheld 3D scanning technology to provide more detailed scans of systems and then to use the gathered data to inform decisions for climate.

3D scanning of “Casa dell’Acqua” Municipality of Volla (via Cool City)

I’ve covered this topic in some detail at Hidden Hydrology. There’s merit to this as a way of approaching climate change through the use of these buried systems, both as a resource for water for irrigation and a passive cooling system and as a way to increase pipe capacity by removing underground streams through daylighting which frees up vital volume for additional stormwater management.

Mapping these has been done for many years, either as a GIS exercise with overlays of historical maps on current conditions and subsequent field verification or looking at current sewer and water and combined systems. This provides a good working system network to understand this hidden potential but not forgotten water in the city. Still, Cool City is taking it to the next level, as mentioned in the article, quoting a project collaborator, Nick De Pace, a professor of architecture and landscape architecture at the Rhode Island School of Design:

“Buried streams and old waterways are not totally lost to time. Many cities have maps showing where a former creek has been shunted into an underground tunnel to make way for aboveground urban development, for example. But De Pace says many of these maps are imprecise, and the new digital scanning and mapping of the Cool City project can bring much more actionable detail to buried streams, aqueducts, and springs. By using this water to irrigate green roofs, parks, and other urban vegetation, cities can counterbalance their heat-trapping hardscapes.”

A low-resolution snapshot of the scan below shows how compelling this composite imagery may be, showing the spaces above and below. Does it aid in climate planning, maybe? They mention that it can be used for irrigation, for more green spaces to mitigate urban heat islands, and for having more water on the surface to reduce heat and provide more cooling. Additionally, the mix of green and blue infrastructure systems can tap into the buried water to help adapt to climate change impacts.

Composite scan of subsurface conditions (via Fast Company)

I wonder, however, how feasible it will be to scan much of the sub-surface infrastructure as proposed above by Cool City, as it’s a mixed bag of small and large pipes and some more expansive and cavernous sewers, depending on the location and the era in which they were implemented. It’s a question to me if it is helpful to have 3D versions of these systems, or is mapping or modeling adequate to see the potential system components and flows and determine how it can be ‘tapped’ to become a tool to fight climate change?

3D scanning is an excellent visualization tool, as it is often difficult to imagine what lies beneath, which is less compelling than a line on a map. As mentioned in the article, understanding the available water resources more clearly is half the battle. The next part is how to operationalize this water for climate strategies. I am interested in seeing more from Cool City, how the technology works, and what solutions come up for using hidden hydrology for climate solutions.


DETROIT: BURIED BUT NOT DEAD

Connecting the dots of Hidden Hydrology and Climate Change, a recent article makes the link between buried streams and wetlands and flood risk while investigating the inequitable distribution of risk by overlaying redlining map data. A recent article focused on Detroit dives into this connection. (“Buried but not dead: The impact of stream and wetland loss on flood risk in redlined neighborhoods” by Jacob Napieralski, Atreyi Guin, and Catherine Sulich; City and Environment Interactions, January 2024.)

While tying flooding to historically buried waterways isn’t novel, this is a unique idea, using mapping to overlay the Home Owners’ Loan Corporation (HOLC) maps showing redlining categories, which are well-documented spatial histories of racial and socioeconomic discrimination. The researchers used these factors (buried streams and redlining grade) as two of the criteria for flood risk along with proximity to coastal zones and intensity of vegetative cover.

Redlining Map of Detroit Metro Area (via Article)

The article is a deep dive, so I will skim on the surface with a bit on the methodology and findings, which are engaging and would be replicable anywhere using similar criteria. The mapping processes, including mapping and DEMs, were interesting. The inference of buried water bodies and flood risk has been borne out in recent events. The authors explain the connections between mapping and current flood risk:

“Although the actual stream channel or wetland surface were buried and built upon, high resolution elevation models (e.g., LiDAR) can be used to reveal the remnants of distinct depressions from these structures, such as meandering stream valleys, in heavily urbanized landscapes. The authors assume that, although no longer occupied by active streams or wetlands, residential homes built on buried stream valleys will experience an elevated probability of flood risk not included in floodplain maps, but also that the process of burial and removal were influenced by income and race embedded in some of the racist housing policies of the 1930s and 1940s.”

Figure from article: “An example of a river in Southwest Detroit identified by the first United States Geological Survey (USGS) topographic map from 1905 (top left), the existing buried stream valley, as evidence from LiDAR data from 2020 (elevation units in feet above sea level), that is capped with residential development (top right), and the intense First Street Foundation Flood Factor risk of parcels near the ghost river (bottom).”

The flood risk data came from First Street Foundation’s Flood Factor, which would be good to explore in more detail. As described, the flood risk of parcels is rated 1 to 10 based on the chance of flooding in a time interval. There were also additional criteria, as mentioned, with coastal proximity, using available data, and vegetation density using Normalized Difference Vegetation Index (NDVI) data to describe the level of vegetation—more on both of these in the article, along with all the analyses.

A figure from the article showing flood risks by type of area “associated with inland, coastal zone, ghost streams, and ghost wetlands within redlined neighborhoods.”

The results reinforce other narratives of disproportionate risk tied to redlining districts that had more marginalized populations. The level of parcels at risk in zones C and D from the HOLC maps, although the amount of burial varied with the presence of most buried streams in HOLC Grade A & B and more buried wetlands in HOLC Grades C & D. As the authors mention:

“Flood risk is disproportionately distributed, caused in part by outlawed, racist housing policies. Understanding where risk is highest can help identify optimum locations for adaptation measures to minimize flood damage in these neighborhoods.”

This does bring up why mapping these streams is important, and the connections to climate change, although not overt, are implied as changes in precipitation and storm intensity make flood risks more frequent and more damaging. As the authors conclude (with a nice reference to hidden hydrology (citation please), the “…role of redlining in present day flood risk applies to cities throughout the United States, as does the importance of mapping ghost streams and wetlands to inform residents of the role “hidden hydrology” may play in increasing flood risk.”

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SAVING SWAMPS TO SAVE OURSELVES

It was a treat to read one of my favorite authors, Annie Proulx (Swamps can protect against climate change if we only let them, New Yorker – 06.27.22), discussing wetlands and their potential for climate change protection. She includes tales of killer herons, stolen rafts, and evocative ideas on our complex relationship with swamps, noting that “Many modern Americans do not like swamps, herons or no herons, and experience discomfort, irritation, bewilderment, and frustration when coaxed or forced into one…”

Illustration by Carson Ellis (via New Yorker)

Swamps were not always reviled or out of favor, as Proulx recounts, in particular the views of Henry David Thoreau, on the subject:

“Thoreau has been called the patron saint of swamps, because in them he found the deepest kind of beauty and interest. He wrote of his fondness for swamps throughout his life, most feelingly in his essay “Walking”: “Yes, though you may think me perverse, if it were proposed to me to dwell in the neighborhood of the most beautiful garden that ever human art contrived, or else of a Dismal Swamp, I should certainly decide for the swamp.”

The connection to hidden hydrology lies in the massive loss of wetlands and the subsequent loss of function to reduce carbon and the numerous ecosystem services beyond that are provided by wetlands in filtering and mediating water in our landscapes. Development in the US meant filling wetlands for farmland, pasture, and eventually cities. The swamps often were a barrier to progress and Proulx notes:

“Across the country, the ongoing stories of vile adventures in the muck made it clear to military, government, and citizenry that something had to be done about the swamps so universally detested. Everywhere there were horrendous mixtures of fen, bog, swamp, river, pond, lake, and human frustration. This was a country of rich, absorbent wetlands that increasingly no one wanted.”

As this occurred, there were impacts, but climate change, and sea level rise in particular, exacerbates flooding, and filled-in wetlands at the margins are poor habitats for the buildings or fields we placed on them that are now in danger of being washed away with more intense storms. There were impacts to landscapes and plantings that reduced habitat. Beyond biodiversity loss, humans will feel the overall loss of resilience more acutely. Still, it is hard to save or restore these landscapes, as Proulx notes in her story of the Black Swamp.

“One authority on water, William Mitsch, has suggested that if ten per cent of the old Black Swamp soils were allowed to become wetlands again they would cleanse the runoff, yet Ohioans remain powerfully anti-wetland. Even private efforts to restore small wetland areas are met with neighbors’ complaints about noisy frogs and fears of flooding.”

Related are mangroves, which are also summarily destroyed, taking with them the ability to reduce storm surges and protect coastal areas in places like the Everglades. As described: “Mangrove swamps have been called the earth’s most important ecosystem, because they form a bristling wall that stabilizes the land’s edge and protects shorelines from hurricanes and erosion, and because they are breeding grounds and protective nurseries for thousands of species, including barracuda, tarpon, snook, crabs, shrimp, and shellfish. They take the full brunt of most storms and hurricanes, and generally survive—but not always.”

Larger, more intense hurricanes can damage mangrove areas with salt or sediment intrusion, reducing their ability to regenerate and removing their support for biodiversity. While natural disasters are a risk, development still threatens these areas despite mounting evidence of their benefits.

“Although climate researchers see mangrove swamps as crucially important frontline defenses against rising seawater and as superior absorbers of CO2—they are five times more efficient than tropical forests—they are in big trouble, and mangrove removal is a constant threat.”

The conclusion for Proulx is to re-establish our love of the swamp, and connect the existential threat of climate change to our ways of life to the natural systems we destroy in the process. Protecting what is there in terms of wetlands and mangroves left standing is the first goal, as well as restoring and expanding these valuable ecosystems, all of which are possible, even necessary as adaptation and mitigation strategies. Proulx ends with a call to action we can all heed:

“It is usual to think of the vast wetland losses as a tragedy, with hopeless conviction that the past cannot be retrieved. Tragic, indeed, and part of our climate-change anguish. But as we learn how valuable wetlands are in softening the shocks of the changing climate, and how eagerly the natural world responds to concerned care, perhaps we can shift the weight of wetland destruction from inevitable to “not on my watch.” Can we become Thoreauvian enough to see wetlands as desirable landscapes that protect the earth while refreshing our joy in existence? For conservationists the world over, finding this joy is central to having a life well lived.”

Note: This post was originally posted on Substack on 12/17/24 and added to the Hidden Hydrology website on 04/22/25.

The recent essay, “Daylighting a Brook in the Bronx” (Pioneer Works, 10.23.24), by Emily Raboteau, focuses on a high-profile stream daylighting project from a resident’s perspective. The project to daylight Tibbetts Brook has been ongoing for many years. For some quick background, Tibbetts Brook originates north of New York City in Yonkers, where it flows from Tibbetts Brook Park, heading south into the Bronx and reemerging above ground in Van Cortlandt Park. It then flows underground the remainder of the way south through the city, as demonstrated on the graphic below, showing the original course of the now-buried waterway and its eventual connection into the last leg of the Harlem River before draining into the Hudson.

Illustration of Tibbetts Brook’s original course in the Bronx – via Pioneer Works

Raboteau, a resident of the Bronx, outlines the project from a personal and experiential perspective, joining some of the local advocates from the Tibbetts Advisory Group and the Parks Department and others working on the daylighting project and highlighting some of the site-based artworks focused around the brook. The positives of the project are notable, as she mentions early on in the essay:

“Daylighting will abate combined sewage overflow, extend greenspace, absorb heat, and relieve chronic flooding in our area’s janky, archaic drainage system, in an act of climate mitigation and as a community effort to solve a mess caused by old crimes.”

I’m not planning on spending too much time recounting her specific words, which I strongly encourage you to take the time to read. I wanted to extract my reflections on a couple of critical themes she highlighted in her essay.

Perfection and Imperfection in Daylighting Projects

The challenges of these projects are myriad, and while striving for a solution that solves all the problems, trade-offs must often be made. She mentions a couple of issues, including the high cost, resistance from the MTA, and the need to underground the creek under rail lines in some industrialized portions. Additionally, gentrification could arise by ‘cleaning up’ marginal spaces during the daylighting project. On one hand, revitalization could improve the area and attract new residents and economic activity. Conversely, the improvements could incentivize new developments and rising costs, displacing long-time residents. Another issue she brings up is the potential lack of good access from some of the adjacent neighborhoods, creating questions of ultimately who will benefit and the overall environmental justice issues at heart in any project like this. As she notes:

“I had so many ethical questions without easy answers. It felt uncouth to ask them of a dream thirty years in the making…. Could it ever be pleasant here? Difficult to picture. Even with the brook resurrected, there would still be the sound of the road.

I wondered: how else might the park change the neighborhood? Will it invite gentrification? Will it grow too expensive to live here? Despite the ecological and economic benefits, will anyone suffer? Can daylighting outpace inundation, or will it be rendered moot by water tables that rise with the sea? If flooding catastrophes continue, what then? Would government funds be better spent moving the most disadvantaged among us out of the watershed to higher ground? Has anyone asked for the brook’s consent? Whose help is sanctioned when it comes to healing the land, and whose is rebuked?

The intersecting concerns and challenges are common in similar projects, no less complicated by threading daylighting through a dense urban center. Patience, openness, and creativity are vital, but the lack of these often results in projects never seeing the light of day. Compromises cannot come at the cost of marginalized communities. Yet, the short-sightedness of attempting to achieve “perfect” restoration in the form of all-or-nothing solutions is equally as damaging to attain nothing. The ability to see multiple solutions that can celebrate, reveal, and restore function requires looking beyond the ecological and including pointing a lens at the cultural context of these projects, balancing imperfection with appropriateness.

Cultural Restoration

The potential of restoration lies beyond the technical aspects and helps us fill the gaps left in implementing imperfect solutions. Raboteau mentions some of the work of artists around the brook, much of it done under the banner of the “Rescuing Tibbets Brook” project as part of the Mary Miss-led project, City as Living Laboratory. Works mentioned include Visions of Tibbetts BrookTibbetts Estuary Tapestry, and Estuary Tattoos, all focusing on artistic and community works around the creek restoration.

Other cultural works are mentioned in the essay. Dennis RedMoon Darkeem‘s upcoming work and the planned daylighting project use harvested mugwort, an invasive species growing near the creek in Van Cortlandt Park, and weaving it into large textiles to act as sound barriers along the course of the stream corridor. She goes into more detail about two other artists. Noel Hefele and his Daylighting Tibbetts en Plein Air paintings (see below), and The Buried Brook, an augmented reality installation by Kamala Sankaram that uses a phone app to trace “the sonic geography of the buried Tibbetts Brook.”

Van Cortlandt Park South Bridge (via Noel Hefele)

Numerous documents and reports on the proposed $133 million project to daylight the brook can be discovered online, touching on many technical challenges. The real story is about grounding the technical with the human dimensions while highlighting the more prominent themes of hidden hydrology. Overall, the result of these cultural explorations to complement the hydrological and ecological, to Raboteau, can be revelatory:

“I appreciate how initiatives like these offer an expansive response to catastrophe, a way to gather, and even a sense of hope. It’s not just the architecture of the daylighting project that interests me, the restitching at the scale of infrastructure, or the civic muscle behind the job, but the metaphysics of the exhumation. Daylighting feels like a cause for ceremony, a chance to pay respect to the body of the ghost river that flows unseen under our feet. Better yet, to imagine the perspective of the brook.”

Both ideas above are inherent in the conceptual potential of what can be accomplished when we think beyond just daylighting as a functional pursuit. First, we must move beyond unrealistic ideas of “perfect” and strive to achieve real projects that inevitably fall short of all that can be accomplished but succeed in not collapsing under the weight of being overly idealistic. Second, to achieve the first, we must continue to explore and expand our ways of engaging with lost rivers and buried creeks beyond. These include the incorporation of a continuum of solutions from the artistic to the ecological.

The recollection of the creek can be expressed metaphorically through art and soundscapes, which provide additional layers of meaning and context to the project’s more functional hydrological and ecological goals. This shows how daylighting projects, while aiming for restoration of function, are not really about attempts at pure ecological restoration but a mix of green infrastructure and ecological design aimed at multiple goals like access to nature for humans and other species, reconnecting communities, and achieving climate-positive design, among many other potentialities.

The potential of these solutions highlighted by Raboteau:

“Daylighting feels like a cause for ceremony, a chance to pay respect to the body of the ghost river that flows unseen under our feet.”


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CONTEXTUAL CODA

Tibbetts Brook has been a topic of interest in my thinking on Hidden Hydrology for some time. I first discussed the Brook in an article on Steve Duncan, a ‘drainer’ type of urban explorer focusing on underground and buried creeks and rivers. He has explored and photographed urban creeks around the globe, but focused on many New York City creeks, including Tibbetts Brook, as I wrote about in a post, “NYC: Watercourses to Undercity” (Hidden Hydrology, 12.28.17).

Tibbetts Brook, photo by Steve Duncan (via National Geographic)

Tibbetts Brook was the subject of the article “Why New York Is Unearthing a Brook It Buried a Century Ago” (NY Times, 12.6.21), which discusses the project goals and objectives in detail. “The city plans to unearth the brook — an engineering feat known as “daylighting” — at a cost of more than $130 million, because burying it in the sewer system has worsened the city’s flooding problems as a warming planet experiences more frequent and intense storms.”

The re-interest in the Tibbets project and connections to climate-related flooding came about as a reckoning of post-hurricane Ida solutions, which included more ‘spongy’ green infrastructure, hardening critical infrastructure, and methods to “unclog drains and widen pipes.” I’ve written about Eric Sanderson’s work of historical ecology and mapping hidden waterways in his Mannahatta and the broader Welikia Projects. He writes a powerful post-Ida opinion piece, “Let Water Go Where It Wants to Go” (NY Times, 9.28.21), where he connects the impacts of Hurricanes Sandy and Ida to areas where waterways were buried, shorelines filled, and wetlands paved over.

“Water demands a place to go. That means making room for streams and wetlands, beaches and salt marshes. It means solving human-caused problems with nature-based solutions. These include removing urban impediments to let streams flow once again, a process known as daylighting; restoring wetlands and planting trees. It also means using the collective power of our community — expressed through tax dollars — to help people move to safer places.”

Overlay of flooding locations (28th Street subway station) in New York City and the location of former wetlands (The National Archives via NY Times)

In my reflection on this article by Sanderson, these connections between hidden hydrology and climate are of keen interest, so this led me to investigate in more detail one of the significant benefits espoused by those advocating daylighting Tibbetts Brook — which was alluded to by Raboteau — the ability to make cities more resilient to climate change by removing base flow water from buried pipes, or captured streams, through daylighting, and freeing up that water to handle extreme rainfall events and reduce flooding. As noted in the NY Times article:

“Though out of sight, the brook pumps about 2.2 billion gallons of freshwater a year into the same underground pipes that carry household sewage and rainwater runoff to wastewater treatment plants. It takes up precious capacity in the outdated sewer system and contributes to combined sewer overflows that are discharged into nearby waterways.”

To learn more about this concept, I wrote on “Captured Streams” (Hidden Hydrology, 12.11.21), taking a deeper dive into the broader idea and its applications globally, drawing on a paper by Adam Broadhead and others, which makes the case that the encasement of freshwater streams in urban sewers is a widespread issue, significantly increases wastewater treatment costs by needlessly treating clean water and the various economic, social, and environmental benefits of diversion. The team included case studies from Zurich, highlighting efforts by the Swiss city to pioneer the idea of urban daylighting to remove base flow.

A diagram of the process, similar to the process envisioned at Tibbetts Brook, from the paper is below.

Diagram of buried stream separation from sewers in Zurich (via Broadhead et al.)

The Tibbetts Brook project aims to be a model case study in this form of separation. While the result will fulfill the goals to reduce flooding, create more resilience, and provide additional positive environmental benefits, the more significant questions Raboteau asks in her essay are vital to allow us to envision the bigger picture and redefine what counts as success: Who is included at the table in planning and design and how are those voices given appropriate weight? Who ultimately benefits? Who has access when the project is complete?

Give the essay a read, and let me know your comments.

Note: This post was originally posted on Substack on 11/30/24 and added to the Hidden Hydrology website on 04/22/25.

There is a rich literary history around hidden hydrology, which I was reminded of by the recent publication of the novel “There Are Rivers in the Sky” by Elif Shafak. The book has gained attention for its interwoven stories around water, and, notably, specific references to ‘lost rivers’.

The novel includes three storylines from different eras, with the characters of Arthur from 1840s London, Narin from 2014 in Turkey, and Zaleekah in 2018 in London, each occupying a specific water-based narrative. As summarized in the Penguin Random House blurb:

“… There Are Rivers in the Sky entwines these outsiders with a single drop of water, a drop which remanifests across the centuries. Both a source of life and harbinger of death, rivers—the Tigris and the Thames—transcend history, transcend fate: “Water remembers. It is humans who forget.”

I’ll try to avoid any spoilers, while I discuss how this relates to hidden hydrology. It’s an engaging tale, touching on the discovery of the Epic of Gilgamesh, a reference to A.H. Layard’s ‘Nineveh and Its Remains’, mudlarking and toshers, some cameos like John Snow and his ‘Ghost Map’ investigations of water-borne cholera near the Broad Street pump, some interesting ideas of water dowsing, and my new favorite cuneiform symbol for water.

Symbol for Water via Dr. Moudhy Al-Rashid

AQUATIC MEMORY

The wildest idea is ‘aquatic memory’, which provides some narrative drive, alluded to in the description above, that a single drop of water connects multiple people through time. The ideas in the book were formulated by Zaleekah’s fictional mentor, who was ultimately disgraced by his pursuit of what others considered unreliable pseudo-science, as noted (187):

“…under certain circumstances, water — the universal solvent — retained evidence, or ‘memory,’ of the solute particles that had dissolved in it, no matter how many times it was diluted or purified. Even if years passed, or centuries, and not a single original molecule remained, each droplet of water maintained a unique structure, distinguishable from the next, marked forever by what it once contained. Water, in other words, remembered.”

The idea seemingly makes for compelling storytelling, however, it seemed a bit underdeveloped in the novel itself in my opinion. It does provide a loose framework for the same water molecule’s memories (loosely based on the real-life ideas of Jacques Benveniste), but fails to explain what this idea means beyond the 3 main characters and their narratives. There’s a ‘summary’ table of the water path through the story at the end, but, to me, it didn’t really mean much and the result is a lot of missed potential.

LOST RIVERS

The lost river content was also somewhat underdeveloped, reading as minimal and tangential anecdotes that seem forced into the story versus being fundamental to any of the plotlines. Zaleekah, the character supposedly studying this phenomenon honestly didn’t do a lot, although she had the most potential to expand the ideas of how lost rivers connect with aquatic memory and even the larger storyline. Her role in the story becomes muddled with a failed marriage, and dysfunctional family dynamics that connect to the greater story in the end but don’t contribute much more.

She makes the bold claim early on, “I’m part of a project — we’re collaborating with scientists worldwide to help restore lost rivers.” (151) but never really discusses what they do in a meaningful way, or how it relates to the story. It leads to a forced conversation touching on the River Bièvre in Paris and giving a cursory ‘these are everywhere’ sort of list, and how we buried them.

She later discusses London’s lost rivers, which reads like a guidebook entry (or a marginally more interesting recounting of Barton’s Lost Rivers of London), rather than something enlivening the story. For instance, this passage (183-184):

“Then there is the River Effra in South London, concealed and culverted, nowadays a conduit for drainage and waste matter, silently coursing under not only houses and offices but also cemeteries, whence it sometimes unearths and carries off buried coffins. There is also the Tyburn, a source of delicious fresh salmon in the distant past, though barely remembered these days, as it flows unseen and unheard underneath celebrated urban landmarks. The Walbrook, once a sapphire-blue river running through the Roman fort of Londonium into the Thames, shimmering like the wing of a dragonfly, provided residents with clean water; now it only feeds into a malodorous sewer.”

Later on, she discovers a note on her desk in her office when searching for something, with the following jotted down: (186)

“HOW TO BURY A RIVER

  1. Build concrete troughs along both sides of the riverbed.
  2. Add a roof to the troughs.
  3. Encase the river completely on three sides, turning it into one long, winding coffin.
  4. Cover the roof with earth, making sure no trace is visible.
  5. Build your city over it.
  6. Forget that it was there.”

It’s all sort of random and snippets like this are a throw-away with little context and less relationship to the overall narrative. There’s nothing to follow up on why we should care and how lost rivers tie into the bigger story. I will admit that having a specific agenda about how lost rivers and hidden hydrology fit into fictional narrative structures is a little pedantic. So my defense is that, on the whole, I liked the story, while I was also disappointed in how these subjects of water and lost rivers were incorporated.

My disappointment comes from a desire to see more opportunities in embedding the ideas of lost rivers into creative writing, to inform and engage a larger audience about the concepts. I am always excited and a little worried when I hear about examples that promise such. Much of the writing around lost rivers only appeals to a very interested subset of people, so connecting these ideas to mainstream culture, popular media, and entertainment could help spread the word to folks who would not be interested otherwise.

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THE EXPANDED LITERARY FIELD

On that note, the first time I connected with the idea of hidden hydrology in literature was a few years back when I wrote an essay related to a novel by Ben Winters from 2016 “Underground Airlines.” The story features Pogue’s Run, a hidden urban stream in Indianapolis, which plays a vital role in the narrative of the novel. Since then, I’ve been collecting previous explorations of literature around hidden hydrology, where subsurface waterways play a significant role in the plot and action of the story.

From a purely hidden hydrology, there’s a short list of titles, some of which I’ve read and others I’ve found or have been clued into by research or other readers. This resulted in a short loose working bibliography.

  • There are Rivers in the Sky (Shafak), 2024
  • Rivers of London (Aaronovitch), 2016-2024
  • Underground Airlines (Winters), 2016
  • The City of Ember (DuPrau), 2013
  • Dodger (Pratchett), 2012
  • Montmorency (Updale), 2003
  • Neverwhere (Gaiman), 1996
  • The Doom of the Great City (Delisle Hay), 1880
  • Journey to the Center of the Earth (Verne), 1864
  • Les Miserables (Hugo), 1862

This investigation intersects with much broader and fascinating areas of inquiry like the Underworld, and a literary subgenre known as Subterranean Fiction. Beware of rabbit holes, as these yield wild threads like Hollow Earth theory (which makes for great fiction). Works span centuries and many genres like sci-fi and fantasy, delving into the literal underworld below the surface. However they do not always specifically touch on waterways, so not all are relevant.

HELP EXPAND THE LIST

The list above is modest, so I hope to expand this initial catalog and explore the full spectrum of possible literary hidden hydrology references. Let me know if you have other examples or favorites you’ve encountered where the concept and context of buried creeks, sewers, and lost rivers play a part in novels, stories, or other fictional works. I would love to expand my overall library of options, hear your thoughts, and explore more deeply.

Note: This post was originally posted on Substack on 10/15/24 and added to the Hidden Hydrology website on 04/22/25.

I spotted this great project this week on LinkedIn and thought it worth sharing. The transformation of urban highways to waterways is an interesting subset of hidden hydrology worth exploring, with some great global examples we will discuss more in the future. This project traces the history of the Catharijnesingel, a canal removed to create an urban highway in Utrecht in the Netherlands, and more recently transformed from hardscape back to its original form as a canal. This provides a great case study on the benefits of public spaces around water, and the ability to restore lost public and ecological benefits through the restoration of waterways.

An overview can be found on the European Prize for Urban Public Space competition site, (Public Space) which recognizes “…all kinds of works to create, recover and improve public spaces in European cities.” The Catharijnesingel project was the winner of the competition in 2022.

For some background, the original Catharijnesingel was a canal that flowed around the defensive walls of the historic city. A park was originally built in the canal zone in the 19th century but was drained and paved over in the late 1960s to 1970s to create space for a major arterial roadway.

Work on the Catharijnesingel before burial (Public Space)

The before picture shows the Catharijnebaan, the roadway built atop the original canal. In 2002, citizens began to discuss the removal of the roadway and restoration of the canal to its original form.

Photo of the Catharijnebaan, the urban highway removed for restoration of the original canal (Public Space)
Image showing the Catharijnesingel after restoration (© 2021 OKRA/Public Space)

The transformation shows the restoration of the canal and revegetation of the banks. The description provides the context of reconnecting with public spaces in urban environments, and the ability to create new, safe, places to access nature and socialize. As noted in the project assessment, on the Public Space website:

“The Catharijnesingel adapts to this new situation by providing pedestrian paths and boat routes and enough space for outdoor recreation. The emphasis on the different microbiotopes of the green areas also makes a positive educational contribution to outdoor activities, where the changing face of nature can be contemplated while walking (or sailing) on the Catharijnesingel.”

The transformation provides access to the waterway for boating, paddleboarding, shady spots, and water access points along the banks, providing much-needed recreation spaces. The project was built in two phases, over 2015 and 2020 with a total restoration area spanning 1.1 kilometers of length.

Photos showing areas of seating adjacent to the restored canal (© 2021 OKRA/Public Space)

There’s also a great video on the Public Space website with some additional historical background and imagery. The project designer, Utrecht-based OKRA Landschapsarchitecten refers to the higher goal of the project as a “…climate-adaptive backbone for the centre of Utrecht,“ and elaborates on the project goals and results:

“In the 20th century Catharijnesingel became Catharijnebaan: an unattractive urban highway dominated by asphalt and concrete. When offered the chance to revert that development, we took the opportunity to push the idea further to its full potential. As the water returned to the historic Canal area, it brought along a new natural park route right into one of the busiest areas in the Netherlands. The result was an urban landscape that was fully connected to the past, the present and the future.”

Aerial View of the restored canal (© 2022 Stijn_Poelstra/Public Space)

These transformations provide a great example of the power to right some of the previous wrongs in urban areas, creating adaptable, climate-friendly spaces. While the canal was never a natural waterway, the project shows that restoring artificial waterways can provide myriad benefits similar to creeks and urban rivers, providing important hydrologic, climate, and public space goals.

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Note: This post was originally posted on Substack on 05/29/24 and added to the Hidden Hydrology website on 04/23/25.

Throughout history, there are numerous theories about building the Great Pyramids of Giza along the Nile River in Egypt. One of the key questions has been the logistics of moving the massive stones, each weighing over two tons. 2.3 million of these blocks of limestone and granite were used to construct the structures, without the aid of modern machinery. Theories for how this was accomplished vary and include methods of transport over land via sleds and rollers, and construction on-site using ramps, and pulleys. Some even attribute these other-worldly feats more broadly to the work of aliens.

Water and the Nile have always been tied to these theories, with the idea that the blocks were floated on the river from distant quarries for use on-site for the Pyramid construction. The structures sit at a slightly higher elevation from the floodplain, some distance from the main channels of the Nile, thus there have been questions on how the stones were transported this last mile from the river to the site itself. The research questions used the tools of hidden hydrology to develop theories on lost channels instrumental to the construction. Two such theories are discussed below.

Khufu Branch

Research on a proposed lost side branch of the Nile being used for aiding in construction was discussed in 2022. I read about it in the article “A Long-Lost Branch of the Nile Helped in Building Egypt’s Pyramids.” (NY Times, 08.30.22), which discusses research results from the paper: “Nile waterscapes facilitated the construction of the Giza pyramids during the 3rd millennium BCE” (PNAS, 08.29.22). The article posits the use of a now-defunct Khufu branch of the Nile River that bent towards the assemblage in Giza to aid in transporting the giant slabs of stone to the building zone.

Conceptual diagram of Khufu Branch, with location of sediment cores (PNAS)

The researcher’s process involved looking at soil cores: “Seeking evidence of an ancient water route, the researchers drilled down into the desert near the Giza harbor site and along the Khufu Branch’s hypothesized route., where they collected five sediment cores.” Analysis of the samples included paleobotany to look at plant fragments and pollen, and matching these species with the presence or absence of water-adapted or dry plantings to determine if the areas were part of a historical water body. The results showed periods of inundation that matched the construction of the pyramids.

This wet period allowed standing water to persist, and the proximity of the Khufu branch provided the ability to extend the reach of the Nile, allowing the construction of smaller canals close to the area of the Giza plateau. The branch is theorized to have dried up around 600 B.C. and the channel moved further away from the site of the Great Pyramids.

Rendering of the Khufu Branch of the Nile (Alex Boersma/Proceedings of the National Academy of Sciences/NY Times)

Ahramat Branch

Several current articles (Cosmos, BBC) have reignited this dialog around these theories of the use of waterways for transporting building stones. They all refer to research from a May 2024 paper entitled, “The Egyptian pyramid chain was built along the now abandoned Ahramat Nile Branch.” (Nature Communications Earth & Environment, 05.16.24). The research team offers new theories about investigating the hidden hydrology to unlock these ancient mysteries. As noted in the article the team makes a similar assertion to the previous work on the Khufu Branch, however, they consider the hydrology differently as a parallel side channel they refer to as the Ahramat Branch. From their abstract:

“Many of the pyramids, dating to the Old and Middle Kingdoms, have causeways that lead to the branch and terminate with Valley Temples which may have acted as river harbors along it in the past. We suggest that The Ahramat Branch played a role in the monuments’ construction and that it was simultaneously active and used as a transportation waterway for workmen and building materials to the pyramids’ sites.”

The map below shows the route of the Ahrama Branch, which was situated on the western edge of the floodplain closer to the location of the Pyramids. In this case, the proximity extended the length of the Pyramid complex, including those to the south near Memphis. The study offers the opportunity for new information, protection of cultural sites, and outline areas to protect from urban development.

The ancient Ahramat Branch. (Eman Ghoneim et al./The Conversation)

The research team discusses the project directly in an article: “We mapped a lost branch of the Nile River – which may be the key to a longstanding mystery of the pyramids.” (The Conversation, 05.16.24). They discuss the methodology of using satellite images, digital elevation models, historical maps, and other sources to identify the traces of the waterway. As they note, there are ‘causeways’ that look to connect at the points of the major construction areas, which were used as “docks” for loading and unloading materials and for workers moving up and down the river.

The idea of understanding the historical hydrological elements of the river provides a unique approach, noted by the team:

“This research shows that a multidisciplinary approach to river science is needed to gain a better understanding of dynamic river landscapes. If we want to understand and protect the rivers we have today – and the environmentally and culturally significant sites to which they are inextricably tied – we need a greater appreciation of the interconnected factors that affect rivers and how they can be managed.”

3D view of the former Ahramat Branch in the Nile floodplain adjacent to the Great Pyramids of Giza. (Nature)

Similar to the Khufu branch, there are theories about what eventually happened to the Ahramat Branch. These include the gradual migration of the channel, tectonic shifts that changed the floodplain drainage, or accumulation of sand filling up the channel, concurrent with other desertification processes at work. The climatic shifts could also have led to more arid conditions and dissipation of the side channel due to lower flows.

Check out the articles and papers for much more detail. I appreciate these larger-scale investigations of hidden hydrology, especially when they intersect with the complexity of ancient constructions, providing hints of how water was instrumental in these monumental endeavors. It shifts the attention away from the typical urban focus of hidden hydrology, which concentrates on the burial and piping of streams in cities, positioning the investigations of hydrology through bigger contexts and longer timescales. And, it’s a pretty cool way to solve a mystery.

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Note: This post was originally posted on Substack on 05/21/24 and added to the Hidden Hydrology website on 04/23/25.

Stories of loss around hidden hydrology are not confined to the environmental impacts and the erasure of natural waterways. They can also include the loss of community and larger societal impacts resulting from impacts like flooding that can result from building communities that are out of balance with the larger hydrological systems they inhabit. This month is an appropriate time to remember Vanport, the community built along the Columbia River in North Portland in the early 1940s by Henry J. Keiser to house World War II shipbuilding workers, and the devastating flood on Memorial Day in May 1948 which destroyed the town.

Aerial View of Vanport, looking (OHS Research Libary, Oregon Encylopedia)

The Oregon Experience documentary from 2016, “Vanport” is available to watch online for free and gives an in-depth history of the evolution of the community and its tragic demise. I wrote about the documentary back in 2019 in my post “Vanport, A Story of Loss” if you want a summary of the evolution and fate of the community.

The rapid development of the community quickly made Vanport the largest wartime housing development, with over 40,000 residents, making it also the second largest city in Oregon at the time in the early 1940s. The community was built around water, nestled near the confluence of the Columbia and Willamette, with channels of the Columbia slough and smaller lakes providing amenities for residents.

Map of Vanport (Maben Manly/Oregon Encyclopedia)

I love the two images from the documentary showing the engagement with water, including an informal beach area adjacent to either Force Lake or Bayou Lake, and a group of kids near one of the sloughs.

Beach Day (Oregon Experience)
Kids on the Bayou (Oregon Experience)

There is some debate about whether the rail embankment to the west between Smith Lake and the Vanport community was meant to be a dike or protection from flooding or merely the berm for the railroad lines. For Vanport the question was irrelevant, as the waters rose quickly and breached the raised earthwork, which allowed the floodwaters to quickly inundate the entire town with a “wall of water”.

The devastation was compounded by the location within the historical Columbia River floodplain and the ephemeral nature of the construction which was rapid and not meant to be long-lived. Other breaches occurred and the entire area inland became a lake. The images, such as below, of houses floating amid the floodwaters, hint at the lack of solid foundations.

Houses floating after the flood (Oregon Encyclopedia)

The devastation was immense and swift, leaving behind the wreckage of the community. Over time the debris was cleared and new uses emerged to erase the remnants of the Vanport community, as it is now part of the Portland Expo Center, Heron Lakes Golf Club, Portland International Raceway, and adjacent industrial development.

Post-flood destruction of Vanport (Portland City Archives, Portland State University)

Vanport was never meant as a permanent community, and the occupation of the site continued well after shipbuilding activities had wound down following the war, providing a refuge for residents who found barriers to housing elsewhere. The suddenness of the destructive forces, the lack of warning and accountability to residents about the dangers of the flooding, and the displacement of numerous residents who became refugees overnight due to the disaster. These compounding forces give this site and its history special meaning for Portanders and the need to discuss, remember, and confront our histories, with lessons to be shared with other communities. The fact that the Vanport has been physically erased from the map also led to its erasure from our memory. It is the same as the burial and erasure of streams, and wetlands, and deserves the same attention to the ecological, hydrological, and cultural forces at work.

The legacy continued with displacement, as a product of racial housing discrimination led to difficulty for groups to find other housing. As mentioned by Abbott in the Oregon Encyclopedia entry:

“Refugees crowded into Portland, a city still recovering from the war. Part of the problem was race, for more than a thousand of the flooded families were African Americans who could find housing only in the growing ghetto in North Portland. The flood also sparked unfounded but persistent rumors in the African American community that the Housing Authority had deliberately withheld warnings about the flood and the city had concealed a much higher death toll.”

It also is important to consider the vulnerability that still exists today. While the installation of Columbia River dams provides some moderation of flood levels that didn’t exist in the 1940s, and the bolstering of true levees and dikes meant to protect from future floods, risks persist along the water’s edge. This protection is aided today through efforts such as Levee Ready Columbia, working to protect from flood risk in the context of development and climate change in the slough.

Vanport Mosaic

As a reminder of our history and place, additional resources provide the background of life at Vanport and the people who called it home for a brief time. This video “Vanport: Legacy of a Forgotten City”, below, is worth checking out for more context about the community and the work being done to keep the memory alive. The video is part of a great resource, Vanport Mosiac, which calls itself “…a memory-activism platform. We amplify, honor, and preserve the silenced histories that surround us in order to understand our present, and create a future where we all belong.”

Their annual Vanport Mosaic Festival is upcoming this year from May 18 to June 1, 2024, which features speakers, tours, and events on-site and at nearby community venues (program here). I’d recommend taking the bus tour (if they still offer it) to see parts of the site not accessible outside of festival hours around the original Vanport community. I wrote an extensive post about the festival and tour in June 2019 “Vanport Mosaic” and they were kind enough to provide a link to it on their site for others to access.

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Note: This post was originally posted on Substack on 05/15/24 and added to the Hidden Hydrology website on 04/23/25.

Milan once boasted a robust system of canals, similar to the well-known waterscapes of Venice. Lacking a large river in the urban area, the canals in Milan were developed in the 12th to the 17th centuries to provide water access and connections that were not part of the original city. The area in the southwest quarter of the city is known as the Navigli district, and today “…remains one of the last true connections the Milanese have with water. The Grand Canal (Naviglio Grande) itself dates back to 1177, making it one of the oldest navigable canals in Europe. Today, it’s packed with bars, cafes, restaurants, art galleries and boutiques; in non-lockdown times, it’s a lively meeting spot or a place for a gentle passeggiata stroll by the water.”

Much of the canal system was buried as part of the modernization of the city, but the system still exists, a few areas see daylight, but most are now underground in pipes. A recent paper by Carlien Donkor, Agenee Bavuso Marone, and Allegra Aprea, “Unveiling Milan’s Navigli and Underground Water Heritage through Integrated Urban (Water) Design.” (Blue Papers, 2024, Vol. 3, No. 1) discusses the Navigli through the lenses of climate adaptation, and water resource management, with a goal to “reclaim Milan’s identity as a “city of water” through a deliberate design methodology informed by the city’s history.”

“Snowfall in the Navigli, Milan” January 1852 (Image source: Angelo Inganni / Blue Papers)

The authors provide additional context for the historical canal and lock system, urban water power dynamics, and how these features had served functional purposes in the original historic city, like draining the marshy landscape mitigating flooding. They also discuss how these can restore the ‘water heritage’, and ways these systems can aid in addressing the contemporary urban issues facing Milan. The system map of Milan provides a hint at some of the main components. Some background, from the authors:

“The Navigli were dug as early as 1179 for defensive purposes, as private irrigation channels, and later as lines of trade and business, and became a part of everyday Milanese life (Aprea et al. 2018). In the past, these artificial rivers were the only source of running water for domestic use; for instance there were many old washing houses along the Navigli like the one in Vicolo dei Lavandai (Ministry of Tourism n.d.). They were even used to transport materials to the Duomo (Milan’s main cathedral) during construction (Tyson 2021; Global Site Plans n.d.). The Navigli system reached its peak during the Renaissance, when Leonardo da Vinci worked on the improvement and expansion of the canals (Tramonti 2014).”

The water system of Milan (Stanqiweb/Blue Papers)
Historical image of canals in Milan (Civico Archivio Fotografico/BBC)

The canals were filled early in the 20th century, many turned into roadways as cars and trains replaced boats for transportation. Like many other cities, the authors note: “…the canals were perceived as sources of disease and odor, and as health and hygiene needs of the growing city became alarming the initiative to conceal them were desirable.”

Incoronata Lock is a remnant of the canal system still visible (Joey Tyson/BBC)

The current system that is the result of this transformation has disconnected residents from the water, changing the nature of the city and diminishing the historical role the Navigli. There have been proposals for reopening the canals and daylighting some of the buried waterways, which are ongoing, however, the authors expand the notion to include a broader spectrum of opportunities to tap the historical legacy of the “city of water” as part of a modern water system. As noted: “By looking into the past and present water infrastructure, surface and underground, technological solutions for collecting, absorbing, filtering and purifying rainwater, formed part of this landscape project.”

This system diagram in the article takes some unpacking, but shows a master plan diagram “showing the hydraulic continuity of the project to the Fossa Interna as well as the three Navigli.” This included incorporating green infrastructure solutions (or in the parlance of some European areas “sustainable drainage systems” or SUDS), which have multiple benefits like restoration of biodiversity, reduced urban temperatures, and amenities.

Waterland master plan (Carlien Donkor, Agnese Bavuso Marone and Allegra Aprea, 2018/Blue Papers).

The ability to use “historical analysis” as a way to create frameworks for modern water systems is highly aligned with the goals of this hidden hydrology project and the authors expand the notion beyond the technical to include the importance of culture in the water solutions.

“For older Milanese, water in Milan evokes a deep nostalgia for the disappeared aquatic city symbolized by the countless depictions in art of the Navigli. The Navigli brought water to the people and people to the water. In the same way, Waterland would do the same. While the call to reopen the canals is good, it should be noted that their water management function is for a different scale of city; this should be translated in a contemporary intervention.”

There is more in the article and references, so would appreciate hearing other’s reactions to the paper’s findings, and perhaps if applicable to other regions. Also mentioned earlier, some of the work is underway to daylight canals in Milan. Notably, a project called Riaprire I Navigli (Reopen the Canals) has a wealth of information on specific worth being done. It is worth a follow-up post for more info (and a good chance to work on my Italian), so stay tuned.

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Note: This post was originally posted on Substack on 05/13/24 and added to the Hidden Hydrology website on 04/23/25.

The article “A cartography of loss in the Borderlands.” (High Country News, 02.21.24) outlines the work of artists Jessica Sevilla, Rosela del Bosque, and Mayté Miranda includes documenting the “Archivo Familiar del Rio Colorado.” This “Colorado River Family Album”, in their words “…brings together contemporary art, environmental education and historical research to document bodies of water that are disappearing or are already gone.”

Archival map overlay – Colorado River Delta (Archivo Familiar del Rio Colorado/HCN)

The work focuses on the area around Mexicali, tracing the memories of rivers and waterways that have been erased via burial or polluted by contamination. The town included diverse Mexican and Chinese workers, who helped develop the Imperial Valley in California’s irrigation canals and working farm fields. This has evolved into a border town with maquiladoras, which has led to an industrial urban pattern. For the artists, the connection to this place is important. “They named the project the Family Album to signal its focus on personal connections to the landscape… to show that our relationship with the Colorado River and the landscape of Mexicali is that of a relative.”

The work incorporates historical source data and art in creative ways to discover the lost elements of the Colorado River area. A video on their You Tube page visually explores the ideas the project is tackling, with English and Spanish subtitles.

The project’s website also outlines many specific projects, installations, and workshops created by the collective and through their curated works. This was a call for entries along with Planta Libre, as noted in the ‘Announcement.”

“We began by launching a call in collaboration with Planta Libre and through a resource provided by FONCA for the reactivation of scenic spaces, seeking to receive memories and memories about landscapes and bodies of water that no longer exist, as well as speculations about alternate futures, pasts or presents. for the rivers, lagoons, canals, lakes that used to run through the city of Mexicali. The categories of the call were photos, anecdotes and fictions about the bodies of water of the Colorado River. We receive fictitious maps, newspaper images, family archives accompanied by anecdotes, among other materials. The call remains open and the search for family archives and oral histories continues.”

Work of artist Fernando Mendez Corona – Scarcity and abundance (Archivo Familiar Del Rio Colorado)

Sevilla’s website includes more information on the project and some graphics. She also includes a summary statement:

“Located between geopolitical, epistemological and disciplinary borders, we investigate our relationships with water and territory; launching the Colorado River Family Archive as a technology to generate situated knowledge, collectively confabulating about the interwoven temporalities of our relationships with the more-than-human in the Colorado River Delta.”

Conceptual Diagram (Jessica Sevilla)

The cross-border dynamic is an interesting element of the work, mediating the governmental and political boundaries imposed on the natural systems, and highlighting the power dynamics of water in the US and Mexico. These liminal spaces provide interesting opportunities for exploration, and in the context of the contested borderlands, inevitably weave politics with water and the ecosystems, communities, and people who occupy these spaces.

Map of Colorado Delta and Imperial Valley showing Laguna Salada (Archivo Familiar Rio Colorado Instagram)

Additional information and updates on the project are available via their Instagram and Facebook.

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Note: This post was originally posted on Substack on 05/10/24 and added to the Hidden Hydrology website on 04/23/25.