rivers – Hidden Hydrology

11 December 2024 22 April 2025

Frog Taxis & Wildlife Ways

Jason Kingcase study, ecology, habitat, lakes, landscape, oregon, places, portland, rivers, watersheds, wetlandsLeave a Comment

In Northwest Portland, Oregon, red-legged frogs living in Forest Park face a dangerous commute in the fall and winter, traversing from their upland homes down to the spawning grounds adjacent to the Willamette River. The species typically is found in conifer hardwood forests that have an aquatic-terrestrial connection to ponds and wetlands as part of their life cycles.

The degree of landscape changes inherent over time is seen in a series of maps spanning the previous century and a half of urbanization, centered near present-day Harborton, the location of a critical habitat connection for the frogs. From the original surveys in the 1850s, the area was lightly developed, and the areas noted as “Timber, Fir, Cedar, Maple, Hemlock, Yew, etc.” showing the zones that would become modern Forest Park and the uninterrupted upland to lowland connections along the Willamette River.

1855 General Land Office Survey Map (via BLM)

By the 1900s and the mapping from the USGS Topographic Survey, some development was happening along the water in the early town of Linnton, and the rail lines were built that started to sever these historical ecological connections.

1897 USGS Topographic Survey (via TopoView)

The current aerial image shows the clear line marking upland to lowland as separated by roadways and more impervious industrial development located along the Willamette River, reducing the amount of shoreline habitat.

The historical upland to lowland conditions has been radically disturbed along the entire margin of Forest Park. We could infer from the series of maps that historically, the frogs had significantly more habitat options along a much larger zone (and even more if you look at maps south of here showing additional lakes and wetlands), and that over time, a series of human-made linear barriers (railroad, roads) and urbanization cut off connections while reducing overall shoreline habitat. This ultimately resulted in a severe decline in several species populations, including the red-legged frogs.

As you see from a zoomed-in area, the major impediment for the frogs is a gauntlet, including a four-lane Highway 30, another smaller side road, and railroad tracks that prevent frogs from safely accessing the breeding area around the Willamette. Described by many as a real-life game of Frogger, the result is documented mass killings of frogs that attempt migration to these zones in rainy seasons.

As a response to the negative impacts of the species, an intrepid group of volunteers has implemented what they call the Frog Taxi. Starting in 2013, as documented on the site Linnton Frogs, the group has mobilized annually to collect frogs from Forest Park, transporting them across Highway 30 and other roads and railroad tracks to get to the breeding around along the Willamette, and then relocating them back across the roadway to the upland. You can see some stats of the group’s work from 2013-2021. The work has continued, and Oregon Field Guide recently did a story on this year’s Frog Taxi, which provides a great overview of the process the volunteers undertake to save this remnant population of red-legged frogs.

Taxi to Where?

Making it across the barrier alone or via taxi only solves one part of the equation. To fully connect the life cycle, viable habitat conditions need to be provided for suitable breeding conditions on the waterside. The landscape of the entire edge of the area used to include the multiple connected ecosystems lakes along a long riverfront edge, including Guild’s, Kitteridge’s, and Doane’s, which is notable as their surrounding wetland margins have been impacted.

Once the frogs can reach the site, the original habitat must be restored to provide suitable conditions. Currently owned by PGE, the taxi “drop-off’“ site is the locus of additional restoration efforts, as noted from the PGE site related to the Harborton Habitat Project:

“The site is one of the largest known breeding grounds for northern red-legged frogs, an amphibian species classified as “sensitive” by the state of Oregon and a “species of concern” under Federal listing status. Additionally, the property is situated where the Willamette River meets Multnomah Channel – a perfect spot for juvenile salmon to rest and find food on their way to the Pacific Ocean.”

The overall goal is to move from taxi service to more uninterrupted connections from the upland forest to the pools to eliminate the game of Frogger, as well as eliminate the need for volunteers to fill the role of taxi drivers. The next iteration involves increasing overall habitat mobility through an amphibian tunnel that will funnel the frogs along the edges and allow them to move under the roadways and rail lines, connecting Forest Park directly to Harborton. As noted, the Harborton Frog Crossing Project proposed this new connection:

“In an effort to save the dwindling frog population, local wildlife officials and the Oregon Wildlife Foundation have proposed to build a highway underpass to grant the amphibians safe passage. The project calls for a concrete culvert beneath Northwest St. Helens Road and Marina Way to help the frogs reach their preferred breeding grounds.”

Other studies are helping pinpoint more specifics related to the locations and magnitude of the problem. There is funding to assess the mortality of the frog populations is underway by Northwest Ecological Research Institute (NERI), and funded by the Oregon Conservation & Recreation Fund Projects and the Oregon Zoo. The specific goals hope to inform the amphibian tunnel, as they state:

“A wildlife undercrossing and/or creating improved wetland spaces that do not require road crossings are the primary proposed solutions. These are expensive, infrastructure-based solutions, and more data is required to find the most appropriate path forward. Specifically, increased data on the rate and location of frogs being killed at road crossings will inform timing and movement patterns to find the best solution.”

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Wildlife Ways

The Oregon Wildlife Corridor Action Plan (ODFW, January 2024) notes that there are naturally occurring barriers to wildlife movement, but the most critical are human-caused barriers that block movement. Within the context, they also discuss how barriers are relative to species, as quoted:

“The most readily apparent human-caused barriers to animal movement are the physical structures that impede or outright prevent connectivity, such as buildings, fences, roadways, solar developments, and dams. The response of wildlife to structures varies by structure type and by species. For example, a fox may be able to make its way around a large industrial complex, whereas for a frog the complex might represent an impassable barrier. While not all physical structures will completely block animal movement, these features are often associated with increased risk of mortality for wildlife due to collisions, entanglement, entrapment, and persecution. Two of the most prevalent physical impediments to wildlife connectivity are roadways and fencing.”

Wildlife crossings, in general, are gaining momentum with various overpass and underpass options that direct and funnel species from habitat areas and provide safe passage through dangerous areas. The focus is often on larger species, specifically deer and elk, here in Oregon, moving between fragmented parcels of land. There is also the potential to reduce vehicle-wildlife collisions, with specific action plans to provide more solutions. These are dynamic opportunities to connect large habitat patches but come at a steep price.

The types of crossings also need to be adapted to the species’ needs. My favorite is the Crab Bridge on Christmas Island in Australia, which provides an almost vertical climb and spans over a roadway to facilitate the migration of red crabs.

Crab Bridge (via Christmas Island National Park)

Another analog is the work being done for fish passage, including strategies for repairing culverts to provide better access for fish, installing tidal gates to better allow movement up and downstream in fluctuating water cycles and implementing fish screens to limit access to certain waterways while providing access to certain areas necessary for the species to thrive. These are less visible than the larger wildlife connections; however, they also come at a significantly smaller cost and can be localized to specific species migration corridors.

The amphibian connections are a microcosm of these types of projects. More modest in scale, but growing in popularity, there are numerous examples around the globe of different types of passages that work for different amphibian species. The hope is that these will continue to do some of the necessary repair work for the severed connections between critical hydrological habitats, hopefully helping the Harborton Red-Legged Frog populations survive and thrive and give the taxi drivers a break.

Amphibian Crossing example from Doñana National Park, Spain (via Research Gate)

If you are aware of other examples of strategies being used to allow amphibians or other species to facilitate movement in fragmented landscapes, particularly those that are disconnected from historical waterways via development, I would love to hear about them.

BONUS: HIDDEN HYDROLOGY READINGS

“The hidden rivers fueling urban floods” (Great Lakes Now, 12.03.24)
“London Reimagined As Tolkien’s Middle Earth In This Beautiful New Map” (The Londonist, 11.29.24)
“Amid big-box stores and industrial zones, salmon are returning to Metro Vancouver streams” (CBC, 11.23.24)
“River revival: Milwaukie’s long-neglected Kinnickinnic River is on the verge of a revival” (Milwaukie Journal Sentinel, 12.04.24)
“Salmon still swim here” (Sonoma Index-Tribune, 11.27.24)

Note: This post was originally posted on Substack on 12/11/24 and added to the Hidden Hydrology website on 04/22/25.

16 November 2024 22 April 2025

Lost Rivers for Underground Energy

Jason Kingaquifers, case study, city, climate, energy, infrastructure, london, maps, research, rivers, streams1 Comment

I was combing through the writings on my original Hidden Hydrology blog, with the idea of bringing in some of the ‘best of’ content still relevant today. This 2018 post, “Underground Energy For London” was worth reconsidering, focusing on a report that identified a significant potential latent in hidden hydrological systems, to provide heat and cut carbon emissions through tapping into underground lost rivers. The specifics came from a group called 10:10 Climate Action, who focused on using London’s now-buried rivers as a source of power, asking the question:

“But what if we could use them to power our city once again? Through the magic of heat pumps, London’s lost rivers could provide low cost, low carbon heating and cooling to the buildings above. They could help us solve the big challenge of decarbonising heat. There’s huge potential for London’s lost rivers to provide clean, efficient and reliable heating for the city – tackling climate change and air pollution. And of course the same technology can be used in other underground waterways like sewers in towns and cities across the country.”.

Unfortunately, the report, nor the group 10:10 Climate Action as far as I can tell, is no longer available online from the original source. I tracked down an online version, so you can download a copy here.

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The use of heat pumps is fairly common practice. Extracting heat from these now piped subterranean waterways, and using this heat for buildings and other uses is more novel, offering an potential alternative power option for London and other cities.

The idea was well-covered at the time: “Lost rivers could heat London to cut capital’s emissions” (The Guardian, 07.08.18) “ noted the potential for underground heat to “cut capital’s emissions”, and the articles “Underground river could heat Buckingham Palace” (The Times, 07.16.18) and “Could Buckingham Palace Be Heated By A Lost River?” (The Londonist, 07.11.18) echoed this, focusing on Buckingham Palace as a visible example of the potential for heating buildings. “London’s lost rivers could heat the city, reduce emissions.” (Earth.com, 07.10.18) took a slightly different slant, focusing on helping curb carbon emissions, similar to the article “A new way to tackle climate change? Heat from underground rivers in London could help cut the capital’s emissions, claim campaigners.” (Daily Mail, 07.09.18).

The concept had also already been implemented in some areas, including Borders College in Scotland, tapping into local wastewater, and the State Ministry Building in Stuttgart, Germany, which tapped into flow from the Nesenbach, a buried river adjacent to the site. A map extracted from the report (image below) shows a number of the potential sites in London, including The Effra, Stamford Brook, The Tyburn, and the Fleet, all of which have potential sites for the use of these technologies. Specific places include Buckingham Palace (mentioned in a few of the articles above), which would tap the Tyburn, Hammersmith Town Hall which flows above Stamford Brook, and other buildings like schools and site elements like heated swimming pools, which is currently being done in Paris.

The following video explains the idea in a specific location, showing an example of a London pub that sits atop an ancient subterranean water source, using this heat pump technology for its heating and cooling for beer and wine.

There are questions on the cost-benefit, and each of these systems would require some infrastructure to be viable, however, it’s pretty exciting to consider the potential of these systems to contribute to energy savings and reduction of carbon emissions. The potential for savings of energy is significant. The Times article noted: “A report from the Greater London Authority concluded that water-source heat pumps could meet 4.8 per cent of London’s heat demand, with sewer heat offering another 6.7 per cent.”

The idea of giving back some of their benefits to the city, even while still being buried underground, is also worth exploration. While the original report is over six years old, I think the idea is still one that seems worthy of revisiting around the globe, identifying projects that could utilize similar techniques, as we search for expanded tools to battle climate change and rising energy costs. I’d be interested to know if any readers know of other cities today using this for district or building scale systems, or projects that have explored this idea of tapping buried rivers in water and sewers for heating and cooling. Let me know if you have any that come to mind.

Note: This post was originally posted on Substack on 11/16/24 and added to the Hidden Hydrology website on 04/22/25.

11 November 2024 08 June 2025

Mitigating Atmospheric Rivers

Jason Kingclimate, oregon, riversLeave a Comment

Anyone who has lived in the Pacific Northwest for some time is acutely aware that the intensity of rainfall events has dramatically shifted due to climate change. When I moved to Portland in the 1990s, the default was a constant, misty drizzle, which has now been replaced at regular intervals with a winter full of torrential downpours amongst a slew of other climatic shifts like hotter summers and significantly colder and snowier winters.

An occasional ‘Pineapple Express’ or ‘Chinook Winds’ were outliers, with occasional wet periods caused by shifts bringing warm air and moisture from the Tropics to northern latitudes. These, we know now, are a form of an atmospheric river, a term from the 1990s that has re-emerged as a new addition to our new climate-change-focused lexicon. Atmospheric rivers are water vapor channels in the atmosphere, which can be up to 300 miles wide and over 1000 miles long, typically occurring in the mid-latitudes.

Atmospheric River animation – via NOAA Earth System Research Laboratory

These storms are part of the water cycle, providing a range of positive benefits and negative impacts. Positively, they can help reduce drought and increase snowpack which can help reduce wildfire risk. The negatives result in too much water, too quickly, causing flooding, mudslides, and other damaging impacts. Researchers have been developing methods to predict atmospheric rivers to prevent some of these negative consequences. They have developed a scale ranking the intensity and danger from AR1, noting a weak system that is “primarily beneficial” up to AR5, which is noted as “primarily hazardous.”

The scale of intensity of atmospheric rivers is a product of the quantity of water vapor by the duration of the event – via USDA Climate Hubs – Atmospheric Rivers

The cycle and intensity of atmospheric rivers will continue to change along with our changing climate, and the water vapor stored in these systems will increase with the continual rising temperatures of the global air and ocean systems. This will mean longer seasons of rainfall, more intense storms, and the need to reconsider our approaches to stormwater management that worked a decade ago but may be falling short.

Connections to Hidden Hydrology

A recent op-ed piece “Comment: Atmospheric rivers require new approach to water management.” (Victoria Times Colonist, 09.31.24) by Alan Shapiro, an environmental consultant, and Tim Morris, director of B.C. Water Legacy, outlines how hidden hydrology can be instrumental in providing resilient green infrastructure for these atmospheric rivers, specifically by reversing the root causes of the problem and reducing resilience: originally removing steams from the urban landscape, paving surfaces, and draining wetlands. They note several ideas like “sponge parks” and well-tested green infrastructure solutions including “Green roofs, permeable pavement, and rain gardens mimic natural water processes by absorbing and filtering rainwater like a sponge before returning it to waterways.”

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The on-the-ground application of this idea can be found in Vancouver, British Columbia. This is highlighted in the article “B.C. atmospheric river a successful first test of community-led rain management project.” (CBC, 09.26.24) which describes the St. George Rainway and the performance of this green infrastructure system during recent extreme rainfall events. I wrote about this project earlier this year, “Vancouver Rainways”, (05.03.24) where I described the goals of the project and the context of hidden hydrology in Vancouver. The recent article highlights the hidden hydrological connection, showing how the rainway follows the route of “an ancient, buried creek” that is a tributary of False Creek:

“The road and homes along St. George Street are constructed above a creek that historically emptied into False Creek. The creek still runs underground, through a series of pipes and culverts — where it hasn’t offered the community adequate drainage for at least a decade, often leading to street flooding and damage to the roadway.”

Daylighting the creek was not feasible due to the impacts on the neighborhood homes and infrastructure. However, the metaphorical river solution of rain gardens utilizes biomimicry principles to provide a linear landscape that provides many of the same benefits of the original creek corridor. The recent atmospheric rivers presented an opportunity to see the project in action where it accommodated large amounts of runoff from adjacent streets.

The ability to trace routes of buried streams provides us with a watershed-based framework to implement green infrastructure solutions that mimic the original hydrology. As you see from the map of Vancouver, B.C. we could start with numerous corridors, using linear green infrastructure solutions like St. George Rainway as a model following closely the street networks. These could be supplemented by larger solutions on public and private property to recreate the functions of wetlands, ponds or other water bodies lost to development over the years. Finally, green roofs and rainwater capture from adjacent buildings and permeable pavements could reduce runoff — finalizing the holistic, integrated strategy.

Map of Lost Waterways in Vancouver – via The Tyee

Hidden hydrology provides these strategies with a watershed-specific framework for green infrastructure that can provide community-wide resilience to extreme weather like Atmospheric Rivers. This is not meant to be full restoration and daylighting, often challenged by site constraints that make it overly expensive or impactful. Linear green infrastructure is a tool in the toolbox, mimicking the function of urban creeks and streams, providing the same benefits, including absorption of runoff, provision of habitat, urban cooling, and visual access to nature, all following the routes of our lost waterways.

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

06 November 2024 22 April 2025

Water Kinship

Jason Kingart, creeks, cultural, ecology, explorations, habitat, landscape, language, literature, oregon, places, rivers, sensesLeave a Comment

The article “Reaching the Light of Day” (Orion, May 23, 2024) is compelling if you’re interested in hidden hydrology. Author Corinne Segal recounts some of the larger themes and projects around “ghost streams,” including work in New York, Baltimore, Auckland, Istanbul, and a handful of other locations. Beyond some of the projects they note, the article poses a larger question regarding our ancient ‘kinship’ with water. This struck me as essential to the conversations around hidden hydrology, so took this as an opportunity to explore further. Various nuances and definitions of kinship span from biological to sociological. For a reference point, I grabbed this quick definition:

kin·ship /ˈkinˌSHip/, noun. blood relationship; a sharing of characteristics or origins.

One could make a case for both parts of this definition. While we’re not technically related, there is a physical biochemical connection between our bodies and water, as our lives ultimately depend on water for our existence. Thus ‘blood relationship’ takes a literal dimension: healthful when we talk of life-sustaining properties; harmful when we talk about, for instance, toxicity due to water pollution. The negatives are often of our own doing, caused by abuse or neglect of our ‘kin’ impacting our bodies in negative ways with disease. It is a kinship of reciprocity, reflecting a link between our treatment of our ‘kin’ and how it is tied physically to our survival.

The second definition here is most compelling, diving into our deeper emotional relationship with water. The ‘sharing of characteristics or origins’ resonates powerfully with our relationship with water. This summer I read the 2023 posthumously published dialogue with Barry Lopez and writer Julia Martin titled Syntax of the River: The Pattern Which Connects. Much of the discussion focused on how Lopez engaged that kinship early in life through language, as a way to know, only later in life, expanding the relationship through a deeper dive into “syntax” to develop understanding and attain wisdom.

An excerpt from his elaborates on this idea:

“I think when you’re young you want to learn the names of everything. This is a beaver, this is spring Chinook, this is a rainbow trout, this is osprey, elk over there. But it’s the syntax that you really are after. Anybody can develop the vocabulary. It’s the relationships that are important. And it’s the discerning of this three-dimensional set of relationships that awakens you to how complex this is at any one moment.”

The only way to develop these three-dimensional relationships is through consistent contact, which requires occupation of and awareness of place. As he visits and revisits his local McKenzie River, he partakes in constant unfolding. He notes some of these observations: “The water has a slightly different color during the four seasons, depending on how much snow and glacial melt is in it. And the parts of the river that are not visible in the summer are visible in the winter, because of the loss of leaves of deciduous trees.”

This connection with water, as Lopez describes it, requires spending time physically interacting with these environments, and conducting actual visits with our ‘kin’ to deepen ties. The wrinkle here is how we adapt this approach for the ‘lost’ or ‘forgotten’, those hidden streams and buried waterways that no longer have a discernable physical presence. The relationship is no longer about observation in the present but about memory. This perhaps is similar to thinking about our lost kin, to think of lost streams in terms of death. In this way. This could be a way to reframe the relationship as grief and loss, allowing us to draw from the deep well of resources to rethink how we remember and celebrate those lost relationships.

Holy Spring in Istanbul – via Orion Magazine

I’m reminded of one of the origin stories of Hidden Hydrology, with author David James Duncan recounting a tale in his fabulous book “My Story As Told By Water”, of the death of one of his favorite fishing spots in his stomping grounds east of Portland:

“At six-thirty or so on a rainy April morning, I crept up to a favorite hole, threaded a worm on a hook, prepared to cast – then noticed something impossible: there was no water in the creek. …I began hiking, stunned, downstream. The aquatic insects were gone, barbershop crawdads gone, catfish, carp, perch, crappie, bass, countless sacrificial cutthroats, not just dying, but completely vanished. Feeling sick, I headed the opposite way, hiked the emptied creekbed all the way to the source, and there found the eminently rational cause of the countless killings. Development needs roads and drainfields. Roads and drainfields need gravel. Up in the gravel pits at the Glisan Street headwaters, the creek’s entire flow had been diverted for months in order to fill two gigantic new settling ponds. My favorite teacher was dead.”

It is sometimes challenging to think of hidden hydrology through the lens of grief, but you can feel Duncan’s pain at the loss of this urban creek. It’s one cut in the death of a thousand cuts that makes up the global tragedy — the devastation wrought throughout the world on waterbodies in the name of progress. However, the impact is muted for several reasons. First, we, unlike Duncan, are often not around when most of these creeks and streams existed in the first place, so we don’t comprehend what we lost. Second, there are remnants and surviving resources that we can still connect within our cities, so the erasure is not complete enough to equal extinction. Finally, these places fade from memory, and, out of sight, out of mind, we forget as we trod over their buried pipes and filled depression blissfully unaware.

When we lack a strong presence of these historical remnants, we tend to feel greater disconnection, the subtle traces not sufficient for us to feel a connection. This drives our need to reveal and reconnect using a variety of methods: artistic, metaphorical, and ecological. This is hidden hydrology as a practice: the reason for us to study old maps, trace the lines of old creeks, and attempt to restore kinship.

Baltimore Ghost Rivers – via Orion Magazine

Hidden hydrological features, unlike humans, can physically be restored and brought back to life in a sense. Beyond just memory, we have the potential for rebirth, through our creative endeavors: historical ecology mapping, painting the routes of streams on roadways, ecological restoration, and daylighting. “Back from the dead” seems a morbid way to think of the processes of restoration, but it gives us the ability to reconnect and restore.

Several other themes can intersect and expand this idea. I recently re-read a portion of Braiding Sweetgrass, where Robin Wall Kimmerer talks of the Grammar of Animacy. I am struck by the similar themes of kinship, as she discusses how we relate to and reference these ecological systems. An excerpt from an Orion article from 2017, “Robin Wall Kimmerer on the Language of Animacy” hints at this idea:

If it’s just stuff, we can treat it any way that that we want. But if it’s family, if it’s beings, if they’re other persons we have ecological compassion for them… Speaking with the grammar of animacy brings us all into this circle of moral consideration. Whereas when we say “it,” we set those beings, those “things,” as they say, outside of our circle of moral responsibility.”

We connect our morality to things we understand. Another theme that this also evokes is the writings of Robert Macfarlane, particularly when he speaks of language and how words connect us to the natural world, another form of ‘kinship’. I wrote eons ago about this lost language of nature, including Macfarlane and Anne Whiston Spirn, both of who also have written about lost rivers. Along with Lopez and Kimmerer, these authors prod us to rethink our ability to connect with our kin, hidden or visible, degraded or pristine.

I’m curious to hear your thoughts on how we can develop and expand these relationships, our ‘kinship’, specifically with places no longer visible and viable. Are there good examples you know of where lost relationships have been reestablished? Do you feel a kinship or even see this as a goal, with other species or with the wider landscape?

Note: This post was originally posted on Substack on 11/06/24 and added to the Hidden Hydrology website on 04/22/25.

15 October 2024 22 April 2025

Literary Hidden Hydrology

Jason Kingcultural, general, history, landscape, language, literature, london, places, riversLeave a Comment

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

Build concrete troughs along both sides of the riverbed.

Add a roof to the troughs.

Encase the river completely on three sides, turning it into one long, winding coffin.

Cover the roof with earth, making sure no trace is visible.

Build your city over it.

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.

11 June 2024 22 April 2025

Urban Surfing

Jason Kingcase study, design, general, places, projects, riversLeave a Comment

There are multiple ways of activating urban waterways, including those focusing on ecological, economic, and social aspects. Urban surfing is a unique way to use waterways in the city for recreation and people-watching, expanding on the use of swimming and boating by modifying the flows of existing rivers or creating artificial waves in waterways. Recently, a few examples of these projects came across my screens, and I was blown away.

Eisbachwelle | Munich, Germany

The most well-known of these urban surf spots is the Eisbachwelle, a standing wave created in the Eisbach River in Munich. According to the article “Eisbach: the mother of all river waves.” (Surfer Today), the site has been surfed since the 1970s, and over time the flow has been modified using planks and ropes to make the swell more consistent. The site hosts surfing competitions and as seen below, all season surfing in the urban core.

A video with more information about the Eisbach is featured in the Vans ‘Weird Waves” series.

Rif010 Urban Surf | Rotterdam, Netherlands

A more recent example that is opening soon, featured in the article “How Rotterdam built a wave pool for surfing inside a centuries-old canal.” (Fast Company, 06.04.24) outlines the plans for the Rif010, billed on the site as the “…world firsts surf pool in the middle of a city.”

Render of Rif010 urban surf spot (Rotterdam Style)

The article delves more into the process of how the park was developed, and what was done to integrate the recirculating system into an existing canal. The project aims to be a destination, with different experiences for beginners to learn, versus areas for seasoned surfers. The club also includes a restaurant and bar, rentals, and several other amenities beyond the surf.

The proposed system, set to open soon after a 12-year process to get it built, produces waves every seven seconds through a complicated mechanical system of pumps, designed by consultants at SurfLoch. According to the article, Rif010:

“…uses pneumatic technology to mirror the way waves form in the ocean. At RIF010, this technology is powered by eight engines that are powered by wind energy sourced from the North Sea. The engines do what the wind does in real life, namely “push and pull” the water to create a succession of waves known as a swell.”

In the United States, a little bit of searching on on the topic yields the story of Big Surf in the 1960s. As noted in the article, “Big Surf: the story of America’s first modern wave pool.” (Surfer Today) discusses the design and development of Big Surf, a totally artificial wave park in Tempe Arizona, simulating real wave action miles from the ocean.

Our focus here is less on the water park model and more on activating urban rivers and waterways. The article “River Surfing: The 7 Best Destinations in the USA.” (American Surf Magazine, 04.03.24) showcases several other examples worth a look, a few of which are more urban and river-based versions.

River Run Park | Sheridan, Colorado

Located near Denver, along the South Platte River, River Run Park was constructed with three surfing waves, called Chichlets (seen below), Benihanas, and Nikki Sixx, each providing more difficulty.

A plan shows the constriction of the river which were originally drop structures in a channelized stream. As noted in the ASLA Colorado award submittal from DHM Design: “The project reconstructed two large, existing drop structures and replaced them with six lower drop structures that include recreational features from wave shapers for surfing and kayaks to water shoots for kids play.”

Bend Whitewater Park | Bend, Oregon

Closer to (my) home, the Bend Whitewater Park provides multiple experiences through modification of the hydrology of the Deschutes River. There are 3 distinct channels, one focused on habitat, another for slow floating, and a third, a whitewater channel with multiple waves for surfing, kayaking, and paddleboarding.

The three channels of the Bend Whitewater Park (Jeffrey Conklin/Bend Magazine)

This video from The Register-Guard shows the part in action.

The list above is not exhaustive (please send me others you know about), but gives a snapshot of some European and US places that provide unique opportunities to carve some waves without a trip to the beach. While not focused on the ecological benefits these provide special locations for use of urban waterways for surfers and spectators.

For some bonus reading, the article “A brief history of artificial wave pools.” (Surfer Today) outlines the historical evolution of introducing waves into water bodies through artificial means, dating back to the mid-19th century! It’s probably worth a follow-up on this interesting tangent to the potential of waterway transformation.

Note: This post was originally posted on Substack on 06/11/24 and added to the Hidden Hydrology website on 04/23/25.

21 May 2024 22 April 2025

Lost Channels of the Nile

Jason Kingarchaeology, canals, cultural, explorations, history, infrastructure, maps, places, riversLeave a Comment

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.

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.

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 05/21/24 and added to the Hidden Hydrology website on 04/23/25.

15 May 2024 23 April 2025

Remembering Vanport

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

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.

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.

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 05/15/24 and added to the Hidden Hydrology website on 04/23/25.

10 May 2024 22 April 2025

Colorado River Family Album

Jason Kingart, case study, cultural, design, history, landscape, maps, mexicali, places, research, riversLeave a Comment

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.”

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.

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 05/10/24 and added to the Hidden Hydrology website on 04/23/25.

11 December 2021 11 December 2021

Captured Streams

Jason Kingcity, daylighting, history, infrastructure, literature, london, portland, research, rivers, zurichLeave a Comment

In response to the NY Times article related to the Tibbetts Brook daylighting to boost capacity for sewers and some discussion on Twitter, Adam Broadhead (@losturbanrivers) sent a great 2013 journal article in Water Research, “Captured streams and springs in combined sewers: A review of the evidence, consequences and opportunities” by Broadhead, Horn, Lerner, which addresses the issue with some research. The article is paywalled, but let me know if you’d like a copy and I can email it to you.

It’s more of a deep dive into some of the research, but the general thrust is that water intrusion in systems has reduced capacity, and that the intentional encasement of streams and springs in pipes reduces the capacity of infrastructure which has a significant economic, environmental and social implications for the infrastructure, as it reduced the baseflow reduces the overall effectiveness of gray infrastructure.

The typical mechanism for intrusion into pipes is related to cracks, which is assumed to be residual groundwater entering pipes in ‘dry weather’ times, where there should be no flow into the system. Groundwater intrusion should not be discounted, but there are other sources of intrusion that are typically not considered, specifically “capture of streams and springs” that impact combined systems capacity.

The figure below shows the change in baseflow and runoff response due to the intrusion of the additional water from streams and springs.

The paper continues to identify the issue, also highlighting the lack of research on this topic, and answers some fundamental questions about how this capture occurs, how to identify it, what is the magnitude and impacts, and ways to manage it. Always interested in language, one item of interest explores key terminology – culverting, extraneous water, groundwater infiltration, sewer inflows and the key element, stream and spring capture. The wordplay is compelling, with some uniquely evocative terms emerging such as parasite flow, misconnected surface waters, sewer leakage and illicit connections all telling a story of water that is in a sense, ‘out of place’.

The how and why is interesting. The most basic version is to take a free flowing stream and incorporate it into a pipe (Type A in graphic above). “Urban streams were frequently culverted and buried, especially during the period of rapid urban expansion in the 19th century.” It’s not a stretch to show that the literature confirms that “old sewers were frequently the covered channels of brooks”, as early development merely hid the streams, but didn’t generate as much additonal flow to overwhelm the piped streams. This happened with additional development and expansion of cities and impervious zones. Often the buried streams become the names for the sewers themselves, such as those specifically mentioned in the article like Garrison Creek Sewer in Toronto and Minetta Brook Sewer in New York.

The baseflow in the streams, unlike sewage, is clean, so the incorporation into pipes and transportation to wastewater treatment plants means additional strain on purification infrastructure with water that doesn’t need treatment. This relates to the original conceptual idea of the Tibbetts Brook example today, with a clear path to remove ‘clean’ water that is reducing combined capacity and overall resilience to deal with larger storms.

Additional capture happens by interception (Type B in graphic above). The most visible example is the massive interceptor sewers in London developed by Bazalgette in response to the ‘Big Stink’ in the the 1850s, acting as a divertor to sewage entering the Thames. This model was copied around the globe, with numerous examples of streams disconnected from their outfalls and no longer making it to their original destinations in the name of water quality. Portland has a large, expensive example of this called the Big Pipe. Many other cities have similar interceptor systems.

Another mode of is by directly capturing and draining spring and seeps in combined sewers, in this case through leaky pipes with cracks and joint openings. Beyond being shoddy construction, this was intentional, designed as deliberately leaky to provide drainage in areas of perched or high groundwater. The 3 types are summarized graphically above, showing variations of combined sewers and stream capture typologies.

The connection here to lost rivers is outlined in the article: “Not all streams and springs are fully captured by these modes of entry. London’s lost rivers diverted into the High, Mid and Low Level Interceptors to the WwTW, (wastewater treatment works) such as the Walbrook, Fleet, Tyburn and Westbourne, do still discharge to the River Thames during heavy storm events, where the original courses of the rivers serve as CSOs.” This is also a pattern in the United States (New York) and Asia (Tokyo) where many of the piped streams never make it to their original drainage water bodies.

The 19th Century was a historic time for burial of waterways, as the rate of urbanization outpaced the ability of natural streams to remove wastes. Thus: “Urban streams that had become open sewers were frequently culverted and buried to provide more sanitary conditions, and this concept is a popular narrative predominantly explaining the conversion of many smaller watercourses to combined sewers (type A).” Beyond the main drivers of pollution reduction and removal of the streams to create land for development, the introduction of seeps and springs provided some necessary baseflow to ‘flush’ sewers as a method of ‘self-cleansing’, and thus was in common practice in sewer design.

It is obviously difficult to identify these captured streams, as they exist under the surface and the original hydrology has been erased. This is where hidden hydrology methodology, using mapping and other primary sources to show where routes of surface flows used to run. Often these were parts of combined sewers, but in some cases the streams were just dumped into pipes. While still important, it is less impactful to combined systems and wastewater treatment facilities as they are often just draining into the same waterbodies that the original creek flowed in to.

Urban exploration is another method of finding routes of streams mentioned (which I’ve covered in depth here in many cities). Mapping of sewers and streams supplement this work, with many cities having robust sets of maps dating centuries in the past to fill in gaps of knowledge of what was there and what was replaced. More sophistical modeling can be helpful, but simple cues like place and street names and other subtle clues can also be extra data to be used to pinpoint old routes of waterways. As mentioned:

“Relevant information on lost urban watercourses helps to establish the pre-development hydrology, but the usefulness of historic maps depends strongly on spatial and temporal coverage, with many older towns and cities having altered the hydrological landscape before the first available maps. The smallest streams and springs may also not be marked on maps at certain scales, particularly intermittent and ephemeral channels.”

The ability to quantify these captured streams is equally challenging – there is adequate knowledge of the phenomenon but lacking in specific data on volumes, routes and baseflow contributions to the systems. While even knowing the levels would be helpful, measuring current flows will yield radically different results today versus pre-development conditions. When quantities can be estimated, the economic benefits can be modeled to see impacts, but this is not common. How the water is distributed is also variable and depends on unique qualities of each stream.

The major consequences are two-fold. First, the introduction of clean stream water increases the amount of water handled by treatment plants, which has larger infrastructure costs in terms of facility construction and operations. Second, loss of surface streams has impacts to habitat, less ecological connectivity, and overall less ecosystem services, including amenity value. It can even have secondary impacts on urban heat by reduction of linear corridors of riparian vegetation. While the anecdotal benefits of ‘flushing’ using the streams was developed early-on, it’s not understood if there’s actual value of these approaches.

A summary of the impacts on the industry are included:

More land and costs needed for wastewater treatment infrastructure
Additional operational costs and use of chemicals
External impacts, such as public health impacts of CSOs, impacts due to loss of ecosystem services due to diversion of local streams, and economic losses.

There’s a more detailed cast study from Zurich, Switzerland that’s worth exploring more. In summary, the authors mention the city as a pioneer through “innovative management of capture streams and springs in combined sewers,” typically through separation using daylighting. This was driven by understanding the “lost social ad environmental values of watercourses that had become culverted and had historically been used as wastewater sewers.”

The benefits to the public include amenity spaces, and also more efficient infrastructure through additional capacity. This dual benefit is key to the Stream Concept, and became codified into planning policy and laws. The dramatic reducing in streams due to urbanization is similar to other cities, with development displacing larger areas of open space and burial of streams, many of which were converted into combined sewers between 1850 and 1980 as seen in the figure below.

The transformation of streams from this point in 1980 shows the changes in approach used by Zurich in the Stream Concept. This is outline in the existing condition (1) which includes stream capture in a traditional combined sewer system, a severing of the hydrological system and piping; the first transformation (2) consisting of separation of the combined systems to removed capture streams, and eventually the final phase of the Stream Concept (3) “separating captured streams and springs into daylighted urban watercourses.”

An important aspect which reflects my approach allows for hybrids of ‘daylighting’ without and zero-sum outcome of daylight or nothing, but allow for a continuum of potential options – as I’ve discussed, between art and science (abstraction vs. pure restoration) or more specifically, interventions that can be located in a triad of artistic, design, or engineering. The street streams, per the articles:

“Naturalistic stream channels and riparian corridors are used where possible, but where space is limited, engineered “street streams” are installed. The latter may have a lower ecological potential, but nevertheless offer architectural value in urban areas.”

The two different typologies seen above show a ‘naturalistic’ approach in a more suburban location (Albrisrieder Dorfbach), versus the more urban ‘street stream’ in Zurich (Nebelbach). The street streams may mimic green infrastructure solutions like green streets as linear corridors, with the conceptual difference of being able to be hydrologically connected from source to outfall to re-connect the old stream corridor, versus merely being site specific insertions.

The article concludes that there is value in disconnecting streams and springs from combined systems (or if we could spin time back, not connecting them in the first place), with economic, environmental and social benefits. The diversion of clean, constantly flowing water out of combined systems provides capacity, and by daylighting (vs. piping) these streams, we have the additional ecosystem benefits. The need for more research is mentioned: “By using daylighted urban streams to convey the clean water baseflow, highly promising social and environmental benefits
have been suggested; an independent peer-reviewed appraisal of this approach would be strongly recommended.” Since this is a 2013 article, I’m curious what additional scholarship has emerged in the last decade.

I also am intrigued by two of the US examples identified in the article were in Portland and Seattle, both of which mention combined sewers with springs running in them. Worthy of more exploration, but both of these do related to a location where a stream was buried and integrated into the pipe infrastructure of the city, which was common in many streams in both cities (for instance Ravenna Creek in Seattle, or Tanner Creek in Portland). Perhaps with the continual increasing impacts of climate change on these systems would drive another look at some daylighting to increase the resilience of the pipes to handle more capacity, while also providing habitat, amenity, recreation, and a range of other essential urban ecosystem services?

Full Citation: A.T. Broadhead, R. Horn, D.N. Lerner, Captured streams and springs in combined sewers: A review of the evidence, consequences and opportunities, Water Research, Volume 47, Issue 13, 2013, Pages 4752-4766, ISSN 0043-1354, https://doi.org/10.1016/j.watres.2013.05.020

Header Image: Figure from the article: Historic loss of Zurich’s streams (water in blue) with increasing urbanisation (grey).