Author: Jason King

Reclaiming Waters in Utrecht

Jason Kingcanals, case study, city, cultural, design, history, infrastructure, places, utrechtLeave a Comment on Reclaiming Waters in Utrecht

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.

Lost Channels of the Nile

Jason Kingarchaeology, canals, cultural, explorations, history, infrastructure, maps, places, riversLeave a Comment on Lost Channels of the Nile

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.

Remembering Vanport

Jason Kingarchaeology, city, cultural, equity, history, lakes, landscape, maps, oregon, portland, redlining, riversLeave a Comment on Remembering Vanport

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’s “City of Water”

Jason Kingarchaeology, canals, case study, city, cultural, history, infrastructure, maps, milan, placesLeave a Comment on Milan’s “City of Water”

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.

Thanks for reading Hidden Hydrology! Subscribe for free to receive new posts and support my work.

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

Colorado River Family Album

Jason Kingart, case study, cultural, design, history, landscape, maps, mexicali, places, research, riversLeave a Comment on Colorado River Family Album

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.

Ghost Streams and Redlining

Jason Kingcase study, city, cultural, detroit, equity, history, infrastructure, lidar, maps, redlining, research, wetlandsLeave a Comment on Ghost Streams and Redlining

The idea of Detroit’s Ghost streams work bridges my two interests by connecting the dots of Hidden Hydrology and Climate Change, a topic that I will revisit often. The post discusses research in Detroit, Michigan, that connects buried streams and flood risks, using historical ecological information overlaid with redlining map data to show the potential negative impacts on historically marginalized communities.

A recent podcast “What We Can Learn from Ghost Streams.” (Next City, 05.01.24) talked about Bruce Willen’s work on Baltimore’s Ghost Streams, as well as the work in Detroit, featuring the research of Jacob Napieralski, a professor of Geology at the University of Michigan-Dearborn. Give the podcast a listen, and as a good companion, he also goes into more depth about this work in Detroit in this article “How ghost streams and redlining’s legacy lead to unfairness in flood risk, in Detroit and elsewhere.” (The Conversation, 03.19.24)

The basis of the research is what are known as ‘redlining’ maps. For a little background, the Home Owners’ Loan Corporation (HOLC) was a government agency created to assess financial risk for mortgage lending for real estate. The tool was used to systematically institutionalize racist policies in cities around the United States by assessing areas inhabited by people of color, poor, and immigrants as much higher risk than those where rich, white residents lived. The process led to disproportionate investment in low-risk neighborhoods and marginalization in those deemed ‘hazardous’ or ‘high-risk’ zones, which ultimately created concentrated areas of poverty through a lack of economic opportunities. The redlining has become a shorthand for the inequity of communities, and mapping allows for looking at how these historical impacts persist in cities today.

Detroit Redlining Map (The Conversation)

The research overlays these maps with other data to extract how the legacy of racist home lending in the past has created more risk of impacts like flooding today. The goal of the study was “… to determine whether a history of waterway burial and/or redlining influenced the overall flood risk of communities today.” The data revealed that the burial of streams and wetlands did impact current risks in the historically marginalized communities. As Napieralski mentions in the podcast:

“Flood risk is very intricately linked to history, and by ignoring history we may be missing some clues that help us move forward.”

Rather than dwell on the negative, the authors mention the positive side of the analysis, noting that most communities have this data and that it can be useful in focusing on where best to employ solutions like green infrastructure or nature-based design solutions, saying: “If communities want to protect residents from flooding, it’s crucial for them to map and understand their “hidden hydrology.”

Buried But Not Dead

More in-depth exploration of the research is found in the journal article “Buried but not dead: The impact of stream and wetland loss on flood risk in redlined neighborhoods.” (City and Environment Interactions, January 2024). The study was authored by Napieralski along with Atreyi Guin, and Catherine Sulich, and their research outlines the mapping to overlay the Home Owners’ Loan Corporation (HOLC) maps showing redlining categories, using buried streams and redlining grades to estimate flood risk. The mapping processes were interesting, including the use of historical documents and Digital Elevation Models (DEMs) to infer buried water bodies and 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.”

Mapping Analyses of Buried Streams and Filled Wetlands and Flood Risk (City and Environment Interactions)

Using data from First Street Foundation’s Flood Factor, 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 that were integrated into risks associated with different types of impact, sorted by HOLC grade. 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.”

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

This does bring up why mapping these streams and wetlands is important. They provide a basis for analysis by using other data as cross-sectional overlays, unlocking connections between impacts that may, on the surface, be unseen. The connections of this work to climate change, of which flooding is a key impact, are clear, as changes in precipitation and storm intensity make flood risks more frequent and more damaging. The authors conclude the

“[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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Note: This post was originally posted on Substack on 05/08/24 and added to the Hidden Hydrology website on 04/23/25.

Vancouver Rainways

Jason Kingart, city, climate, creeks, cultural, daylighting, design, ecology, habitat, history, infrastructure, landscape, maps, parks, places, precipitation, streams, vancouver, watersheds1 Comment on Vancouver Rainways

The Pacific Northwest has long been one of the innovation hubs for green infrastructure solutions. Portland, Seattle, and Vancouver have been leaders for over two decades in developing innovative options to manage stormwater in urban environments, creating decentralized solutions such as green streets, rain gardens, green roofs, and permeable pavings that have now become standard solutions and spread widely to regions.

In places with high rainfall, the initial drivers for these solutions were managing stormwater and reducing combined sewer overflows (CSOs) where rain and sewage mix in pipes, which, in extreme events, overflows into waterways creating pollution issues. The importance of green infrastructure has grown to include multifaceted outcomes, helping mitigate climate impacts by reducing flooding and providing shade to reduce urban heat, and providing ‘green’ solutions over ‘grey’, increasing habitat and helping minimize biodiversity loss.

Thinking strategically about where these solutions are built is key to success. Looking beyond site-specific and one-off strategies, the goal is to provide larger overarching frameworks for how these strategies are planned to work together to achieve holistic results, and ways to plan for these interventions. “How Rainways Could Restore ‘Raincouver’” (The Tyee, August 24, 2023) highlights some of the recent work in Vancouver. What they refer to as ‘Rainways’ are the green infrastructure interventions that have been proposed by City and community groups going back to 2012 built around water in the city and ways to discover and celebrate it.

St. George Rainway illustration (City of Vancouver, The Tyee)

The St. George Rainway is another precursor to some of the work. It was studied and determined that true creek daylighting would be a challenge, due to infrastructure and costs, however, there were other ways to functionally and metaphorically restore the essence of buried creeks through green infrastructure and art. Neighbors have implemented several interventions, including street murals that follow the meandering route of the old creek.

St George Rainway Street Mural (St George Rainway Project)

To further visualize the potential benefits, the team here are some good before and after visuals on the site, transforming asphalt into rain gardens with pathways and plantings.

Visualization of Rainway along 12th Avenue to Broadway (St. George Rainway)

Rain City Strategy

For a deep dive, the Rain City Strategy is a comprehensive document published in 2019 to celebrate water and address environmental and social challenges. The basis is green infrastructure in the city, using streets and public spaces, buildings and sites, and parks and beaches. The overall goals are water quality, resilience, and livability. This includes the management of stormwater to protect and increase water quality, facilitate infiltration, and become more adaptable to climate impacts by mitigating flooding. Beyond function, creating spaces that provide equitable access to nature and benefits to the community are inherent in solutions, assuring they aren’t just solving one problem but many.

Rain City Vancouver (City of Vancouver)

The report includes references to the original buried and disappeared streams that existed before urbanization. These maps build on the work going back almost 50 years to research done by Sharon Proctor in her book ‘Vancouver’s Old Streams’, published in 1978 with a sweet hand-drawn version of the map below (read more about this in my 2016 post “Vancouver’s Secret Waterways”).

The execution of more formal St George Rainway design concepts is available from 2022, showing how the concepts are applied to the segments of St. George Street, with plans and sketches illuminating the proposed condition.

Concept Design – St. George Rainway (City of Vancouver)

The holistic proposal of looking at the macro-level buried rivers as the genesis for these community interventions. The benefits of the designs are manifold, as noted in the project summary:

  • Reduce street flooding
  • Treat rainwater pollutants from roadways
  • Reduce combined sewer overflows into local waterways
  • Enhance climate resiliency
  • Increase biodiversity
  • Cool the neighbourhood during summer heat

CODA

It’s great to see this connection between hidden hydrology and innovative stormwater solutions take shape in such an intentional way. In the past, cities have looked at these buried stream routes in locating facilities and creating smaller sub-watersheds. For some background, in a presentation back in 2006 at the National ASLA conference, I did a presentation entitled “Neighborsheds for Green Infrastructure”, where I made a case for using the routing of buried streams as a framework to implement green infrastructure solutions in Portland, Oregon. I’ll dig up some of these ideas and repost them, as they may be worth revisiting, in the meantime, I mention it in part of my introductory “Ecological Inspirations” post at HH (see image below). Stay tuned for more on this.

Neighborshed Diagram from 2006 in Portland (Jason King)

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Note: This post was originally posted on Substack on 05/03/24 and added to the Hidden Hydrology website on 04/23/25.

The Lost Suburbs of Los Angeles

Jason Kingarchaeology, case study, city, creeks, cultural, ecology, habitat, history, infrastructure, landscape, los angeles, maps, research, streams, watershedsLeave a Comment on The Lost Suburbs of Los Angeles

Strong connections exist between hidden hydrology and the larger work of historical ecology, in terms of methodology and the work to piece together complete stories from fragments of disparate sources. Often the traces of historical waterways inform the larger ecological patterns of places to establish baseline conditions, and historic vegetation patterns, and begin to establish markers to document change. The overlay of indigenous occupation is an additional element, however, it is often hard to reconstruct due to a lack of physical documentation. Examples of projects successfully implementing this type of work are valuable case studies.

A recent article, “Tribal leaders and researchers have mapped the ancient ‘lost suburbs’ of Los Angeles” (Los Angeles Times, October 9, 2023) explores a successful process, highlighting work by groups using these techniques to study six village sites in the greater Los Angeles region. These “lost suburbs”, in this case, are the original settlements and villages within the LA Basin, where, as noted in the article, “…culture thrived here for thousands of years amid a landscape of oak and walnut woodlands riven with waterways teeming with steelhead trout and prowled by wolves and grizzly bears.”

Ancient routes and key village locations (LA Times)

Three tribes, the Chumash, Tataviam, and Kizh-Gabrieleño collaborated with diverse interdisciplinary academic researchers to piece together a tapestry of inhabitation, as noted in the LA Times article by one of the project leads, UCLA’s Travis Longcore: “We had to dig deep for evidence of the great society buried under our modern empire of terraced and graded slopes, rivers sheathed in concrete, industrial development, freeways and sprawl.” 

These provide a trail of evidence to follow for appropriate ecological restoration and responses to climate change. Hidden hydrology is one essential key to the understanding of these ancient places. From the LA Times: “One map reveals the locations of streams, wetlands, vernal pools, and tidal flats that were buried or drastically altered to accommodate urban development.”

Comparison of development impacts on waterways (LA Times)

This is a part of the full historical ecology of the region discussed in the following section. Understanding the pre-colonization waterways allows for restoring places informed by an authentic indigenous history. As noted by Matt Vestuto, one of the collaborators from the Barbareno/Ventureno Band of Mission Indians:

“…the mapping project offers hope for a long overdue reappraisal of Native American history… Almost overnight, we were disenfranchised from the landscape — but our people are still here… now, the challenge is to restore the environment, and rebuild our nations.”

The project is part of a larger Los Angeles Landscape History project, with a report published in 2023 outlining the details of this analysis of the Indigenous Landscape of the city. A key component of the analysis is mentioned in the Executive Summary:

“Descriptions of the historical landscape patterns and function have led to a conclusion that this landscape and region cannot be understood without listening to the stories of Indigenous people who managed this land and thrived for thousands of years before the arrival of European settlers.”

A key part of the work is cartographic regressions, which include reconstruction of the topographic history and hydrological patterns using old maps, aerial photography, and other archival sources, like texts, drawings, place names, historical accounts, and archaeological work. The analyses look closely at trade networks, historical flora and fauna distributions, and their impact on habitat, and provide the blueprint for future restoration. As noted in the Executive Summary:

“This project is unique because a commonly shared, detailed map of the historical ecology—the flora, fauna, hydrology, and landforms, that evolved within Southern California’s Mediterranean climate over millennia and supported human populations for 9,000 years, has never been developed.  Individually and cumulatively, the results of this research are vital resources to all regional and local planning efforts involving sustainability, habitat restoration, and preparing for climate change.”

Story Maps

An interactive Story Map is also worth checking out, providing a visual executive summary of the report. Focusing on the section related to Historical Water Features, the team traces stream routes in intervals, including 1896-1903 and 1924-1941, with the ability to compare, via slider, the two time periods as shown below, and highlights the radical change of regional hydrological patterns as the city developed.

Historical Water Features 1896-1903 (LALAH Story Map)
Historical Water Features 1924-1941 (LALAH Story Map)

The citywide mapping of vegetation types is directly related to these original historical waterways, and an interactive map, based on the Military Grid Reference System (MGRS), using a 1km grid, to provide map data in cells of potential natural vegetation (PNV). This is described in the Story Map as the “…vegetation that would develop in a particular ecological zone or environment, assuming the conditions of flora and fauna to be natural, if the action of man on the vegetation mantle stopped and in the absence of substantial alteration in present climatic conditions.”

Map of Hypothesized Potential Natural Vegetation of the Los Angeles Region (LALAH Story Map)

The connections between hidden hydrology, historical ecology, and indigenous occupation are more than just understanding the past. As the researchers point out, the ability to employ this data for solutions to loss of biodiversity, climate change impacts, and other challenges, while celebrating the cultural legacy of place, is key. There’s a wealth of information worth studying this model in more depth, to better understand the Los Angeles Basin ecology and hydrology and to refine and adapt this approach to other regions, specifically centering Indigenous stories as a key component in historical ecology work.

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Note: This post was originally posted on Substack on 05/01/24 and added to the Hidden Hydrology website on 04/23/25.

Ghost Rivers of Baltimore

Jason Kingart, baltimore, case study, city, creeks, cultural, design, explorations, maps, places, streamsLeave a Comment on Ghost Rivers of Baltimore

One of the cooler examples of hidden hydrology art in the past year is “Ghost Rivers”, the brainchild of designer and artist Bruce Willen of studio Public Mechanics.

Ghost Rivers (Ghost Rivers)

Envisioned as a “…public art project & walking tour, rediscovering hidden streams and histories that run beneath our feet.” Willen uses traffic striping and signage to highlight multiple sites around the city, particularly Sumwalt Run, a buried creek that “now flows entirely through underground culverts beneath the Remington and Charles Village neighborhoods.”

The site includes some great background, including the history of the streams and their burial, along with some great illustrations of the path as it winds through

Stream burial (Baltimore DPW Archives, Ronald Parks – Ghost Rivers)
Sumwalt Run pipe (Ghost Rivers)

The installation itself is simple, using durable thermoplastic traffic striping in a wavy pattern that allows the line to engage with people in multiple ways and follow curbs and walks – so it is interrupting the linear flow patterns of walkers, cyclists, and driver throughout the city. This allows the eye and the curiosity to wander along these paths and connect the dots.

Images of the meandering blue path in the public realm (Ghost Rivers)

Self-guided walking tours are available and will expand as more sites are included, along with a Google map to track the route and key points. The signs are also simple, but bright and noticeable for those passersby, allowing for a bit of interactivity as they line up with the views of the meanders, and provide some background information and QR codes to scan for more engagement.

Ghost Rivers Sign (Colossal)

The summary statement explains the idea of connecting us with these hidden creeks.

“Below the streets of Baltimore flow dozens of lost streams. These ghost rivers still cascade from their sources, the many natural springs around the city. As the street grid sprawled outward from the harbor, these verdant waterways were buried in concrete tunnels. They now run deep beneath our rowhomes, channeled into the city’s storm sewers, hidden and mostly forgotten. You can sometimes hear their rushing waters echoing up from storm drains.”

The site also includes awesome resources for more information, history, daylighting resources, and other artistic interventions worthy of a follow-up, including a few I’ve posted about in the past and a few new ones. This is a model that is highly replicable in almost any city, using materials that are simple and evocative in unique ways to highlight those subterranean stories and make us reconsider our relationships with the hidden hydrology.

Closeup of Sumwalt Run marker (Ghost Rivers)

The idea is one of the most cohesive and elegant takes on the idea of revealing creeks using blue lines tracking the historical routing of the waterways. It draws upon precedents, mentioned by applying traffic coating, markers, or paint to mark the route of creeks, most similarly artist Sean Derry’s work in Indianapolis ‘Charting Pogue’s Run” and Henk Hostra’s “The Blue Road” in Drachten, The Netherlands, the proposed “Ghost Arroyos” in San Francisco. Another art-based example from Baltimore is the “Green Alley” street painting, and more loose, ephemeral versions in the St. George Rainway in Vancouver, B.C., in São Paulo, Brazil as part of the Rios a Ruas project, Stacy Levy’s Stream Sketches in New York City.

There are lots of examples of this type of project, and it is interesting to see the different ways a simple blue line can be used to engage in revealing historical layers. So let me know if you have other favorites you’ve seen.

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

Exploring Canada’s Buried Rivers

Jason Kingcreeks, daylighting, history, maps, montreal, places, streams, toronto, vancouverLeave a Comment on Exploring Canada’s Buried Rivers

A recent CBC News interactive “Buried rivers flow under Canadian cities, hidden in a labyrinth of tunnels and sewer pipes. Will we revive them or let the waterways fade from memory?” (April 3, 2024) provides a deep dive and great graphics and maps for hidden hydrology in three cities, Toronto, Montreal, and Vancouver. Jaela Benstien and Emily Chung do a great job of highlighting both the timeline of urban stream disappearance and some of the ways the streams are coming back to life.

The narrative of disappearance mirrors many other cities, including pollution and diseases like cholera and typhoid turning waterways from amenities to dangers. Encasement in pipes became a way to remove the sources from contact and also opened up future land for development.

Images of sewer construction in Montreal’s Saint-Pierre River in the 1930s (Archives de la Ville de Montréal – via CBC)

The article explores particular creeks in Toronto including Mud Creek, where Helen Mills, founder of Lost Rivers, gives a tour of the remnants and traces of the urban waterway. It also discusses Taddle Creek which provides one of those dramatic before-and-after visuals we all dream of when envisioning the hidden hydrology in the modern context.

Taddle Creek near Toronto University, in 1861 (uc.utoronto.ca/public domain/CBC)
The same view in 2023 (Emily Chung/CBC)

The methods we used to show lost rivers are worth more exploration here, and the news interactive does a great job of using a scrolling format and some oblique aerial maps of the three cities, such as Toronto below.

Image of Toronto’s Lost Rivers (CBC)

The interactive aspect allows for more context for places, such as the route of Mud Creek through the Evergreen Brick Works, using a revealing overlay w/ aerial imagery with powerful effect.

Overlay of Mud Creek in the Evergreen Brick Works in Toronto (CBC)

The story similarly looks at both Montreal and Vancouver in-depth, so check out the full exploration. For some added context, I previously covered some of the Canadian cities in some depth with Vancouver’s Secret Waterways (November 2016) and Toronto’s Lost Rivers (July 2017), and also a more in-depth discussion of the great documentary Lost Rivers (November 2016).

There’s a focus on daylighting, and they include Luna Khirfan, a professor of planning at the University of Waterloo who has done extensive research on stream daylighting projects around the globe. She mentions other cities around the world that are doing work on daylighting and restoration of urban creeks, such as Zurich, Switzerland, Seoul, South Korea, Berkeley, California, and Yonkers, New York, which we will cover in more depth in the future posts.

The imagery emphasizes the constrained conditions of some of the waterways that were not buried and still exist in daylight, but have been channelized at the margins of. This image of Still Creek in Vancouver highlights the conditions of many creeks.

Still Creek in Vancouver, BC (Ben Nelms/CBC)

Even in a constrained condition, there are benefits to the visible creeks, in terms of cooling, habitat, and biophilic connections to water and nature. The story also makes the key connection between these lost rivers and contemporary climate change issues like flooding and urban heat islands. As noted:

“Climate change and urbanization are heating and flooding our cities. Restoring buried waterways — and their riverbanks — could be one answer to many problems: cooling heat islands, absorbing carbon dioxide, cleaning the air, reducing flooding and providing a habitat for wildlife and native plants.”

The story is engaging and informative, and more cities deserve that deep dive into the history and potential for exploration of hidden hydrology and potential daylighting and restoration. I also do appreciate the link to my Hidden Hydrology site for more info!

As a companion piece to the news interactive, the CBC podcast What on Earth with Laura Lynch from April 14, 2024 “Buried under cities, rivers are a climate wonder in waiting” a 30-minute exploration by Jaela Bernstien (who co-authored the previous story), and Lynch of some of these same topics in audio format, in Montreal’s Saint-Pierre, Toronto’s Mud Creek and Vancouver’s Still Creek. Through discussions with Kregg Hetherington, Amir Taleghani, and Helen Mills, it captures the beauty of hidden hydrology exploration and discovery and highlights the goals of ecosystem restoration and climate change solutions embedded in restoring lost rivers. Luna Khirfan is also part of the dialogue, discussing her work at the University of Waterloo around stream daylighting, the challenges of daylighting, and other world global cities like Zurich that have championed the idea.

Give both the article a read and the podcast a listen and let me know what you think.

Note: This post was originally posted on Substack on 04/20/24 and added to the Hidden Hydrology website on 04/20/25.