An interesting case study in hidden hydrology from a region I’ve yet to discuss, Greece. Via the Telegraph, an article “Athens hatches ambitious plan to uncover fabled river, once the haunt of Socrates, and turn it into a park.” The river in question is the Ilissos, which, due to lack of maintenance on the subsurface tunnel in which the river flows has led to structural issues that has caused issues with the tram line running on the surface, and opened up opportunities for restoration of this ancient waterway. As mentioned:

“An 1821 water colour of the Ilissos River and the Temple of Olympian Zeus” – via Telegraph (image credit Alamy)

“Urban planners have suggested that rather than spending millions of euros on reinforcing the tunnel and repairing the track, the tram line should be diverted along a different route and the river opened up. They are proposing the creation of a park along a one mile stretch of the formerly forgotten river.”

Some context on the significance of this river, via the HYDRIA Project, “Ilissos river was considered in antiquity as the second main river of Athens, forming an horizontal landmark in its southern and eastern sides. Ancient writers mention various activities by its banks, varying from civic processes, cults -including a sanctuary dedicated to the river himself, by Ardittos hill- or social walks and philosophical endeavours in idyllic landscapes, as for Socrates and his disciples (Plato, Phaedrus 229-230, link). “

View of Athens from the River Ilissos – painting by Johann Michael Wittmer – via Greek City Times

Due to the dry climate, the Ilissos and the other river in Athens, the Kifissos, are often dry, as mentioned in the article. “Given Greece’s dry, hot climate, neither is huge – they are nothing like the Thames in London or the Tiber in Rome.” They do, however, act as places for floodwaters to run after winter rains, and the depths can reach up to six feet.

Map of Ancient Athens (Ilissos River highlighted by author) – via Ancient History Encyclopedia

From the BBC “Athens to open up ancient river“, the plan by Nikos Belavilas from the Urban Environment Lab shows the route of the proposed daylighting, restoring it after it was paved over in post-WWII development. You can see the location of the current configuration in the context of the historical routing above, including the Stadium and the Temple of Olympian Zeus, built by Hadrian.

Map of the Ilisos – via BBC (image via Urban Environment Lab)

Beyond daylighting, the restoration also has bigger implications, as a strategy to avoid future issues. As mentioned in the BBC article:

“But it is not just a simple matter of reclaiming the city’s past, but also of saving its present.”If the Ilisos tunnel collapses, it will block the natural course of the river, and could flood the entire city centre,” Mr Belavilas warns – “That doesn’t bear thinking about.”

Currently, only a small section is now visible on its path from the mountains, as mentioned in the Telegraph: “It originates in the mountains on the edge of the city and eventually flows into the Saronic Gulf, after passing almost unseen beneath the streets of the capital. It does emerge briefly, in reed beds behind the Temple of Olympian Zeus, which was built over several centuries starting in the second century BC. “

The only uncanalised part of the bed of Ilissos river that once ran outside the old city of Athens. – via Wikipedia

HEADER: River Ilisos and Stadion Bridge, ca. 1900 – via Wikipedia

GREEN LAKE

  Green Lake
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Leaflet, \r\n© OpenStreetMap contributors

I’ve been wanting to write about Seattle’s Green Lake, which is an addition to round out the post these small Seattle lake stories, and supplement the coverage of the larger lakes Union and Washington.  Green Lake has a special place for me, having lived close to it our entire time in Seattle, it’s been a place for fun, recreation, and even protest.  This really cool cross-time image from Then & Again shows the juxtaposition of the current with the old, and Green Lake spanning this , here with “…the majestic USS Macon gliding above Seattle’s Green Lake on August 22, 1934. The airship was traveling to its new station near San Francisco but took a leisurely route with time for a number of photo ops along the way.”

The history of the lake goes back to similar era to the smaller Bitter and Haller Lakes and the larger Lake Union and Washington, as mentioned on the Seattle Parks website: “Geologists say the Vashon Glacial Ice Sheet, which also formed Puget Sound and other area lakes, formed Green Lake 50,000 years ago. Dredgings of Green Lake have produced volcanic ash from an eruption of Glacier Peak that occurred about 6,700 years ago.”  The original lake was lowered 7-8 feet as park of early 20th Century Park improvements, and this 2014 article from Seattle Greenlaker  ‘Olmsted and the Origin of Green Lake Park‘ offers a good introduction to the modern incarnation of the park and this process. In that post, it links to this great map from 1907 from the National Association of Olmsted Parks, which shows the development of Green Lake Boulevard and the areas near the lake as part of this process, and the first evolution of Green Lake as part of the overall Park System.

Via Seattle Greenlaker – Caption: Courtesy Frederick Law Olmsted National Historic Site, National Park Service, 02714-21. Used with permission.

If you were, like me, temporarily disoriented for a bit, it helps to rotate this drawing so north is up, and the more familiar shapes and lobes of the lake become clearer. I’ve also highlighted the old shoreline (dashed line) and the new shoreline (solid line w/ blue fill), so it’s clearer where the drawdown left space for the trails and more usable open spaces, with amenities like Boat Houses and beaches.  The map also has information on the inlets and outlets, which I’ve highlighted below in a bit more detail for reference.

If you remember back a bit to my post of the exploration of Licton Springs, the sketch above is instructive, as this inlet #1 shows an inlet with a specific reference: the “Brook inlet box culvert 2’x6′ from Licton Min. Sprg.”, showing the subsurface connection to the spring that had been filled in previously but was still flowing from the north.  A Bathhouse is shown, which does not currently exist, but there is a swimming beach access which is still in place today, along with the splash play and some open spaces.

There is another pair of inlets #2 a bit further west, near Corliss Avenue, with a label “Inlet box 1 1/2′ x 2′” and near there is one with a note “Old Inlet 18″x18” wood box” which has a note “very little flow now – some sewerage seems to enter it now.”

The final inlet #3, is to the west, showing a connection to an “Inlet-brook, 6′ wide, 3″ deep” that comes from the northwest, running under the streetcar track in a culvert before coming into the lake.

On the opposite side of the Lake, heading southeast, there is the Outlet, which is marked #4, near 4th Avenue (a few blocks from the proposed boulevard which would become current day Ravenna Boulevard), which was the natural drainage of Green Lake into Ravenna Creek.  The reconfiguration of this zone and the shift of the shoreline created a larger area that now has sports fields, as well as a boat house and what is a popular beach access spot today.  This is also adjacent to the larger commercial zone which is the hub of activity adjacent to the lake.

 

These flows in and out correlates somewhat with the 1850s maps, but does closely align with the the USGS Topo Map from 1894 (see below) of Green Lake that identify three inlets from the north and the Ravenna outlet heading southeast – which does line up with the hydrology shown on these 1907 drawings.

Historical Topographic Map Collection

The formal plan as presented to the Seattle Parks Commission in 1910 mirrors much of the modern day condition, with the lowered water levels providing for perimeter trails, new plantings, a new island, some amenities such as beaches and boathouses, and the boulevard that rings the park (the western half of which was transformed with the routing of Aurora Boulevard (Highway 99).

 

And another version, this one from 1925 showing a more colorful version of this, “Proposed Plan for the Development of Green Lake” via the Seattle Municipal Archives Digital Collections.  This map dashes in the existing and proposed shorelines

I posted previously about the fun bathymetry maps, which included Green Lake. Another map I like is this one ‘Showing Depth Contours of Green Lake’ via the Seattle Municipal Archives Flickr page, which was done in 1938 as part of the Sanitary Survey by the WPA and featured in the “Report on Green Lake Algae Control”, which highlights perennial water quality issue . It reinforced that the lake is relatively shallow, with maximum depths no greater than 25′ feet on the western edge.  It also identifies some of the hydrology, including overflows, intake from the City resevoir, and to the west, a “permanent inlet from deep springs” which is a fascinating addition both due to it’s mystery and also it’s location, which is not shown on later maps but does appear in the 1950s map.

The history of the lake beyond that Olmsted plan has many facets and this Chronology is helpful to see the evolution.  There many tales (and History Link is a great resource here) that connect with Seattle history, such as in 1869, when David Denny “…kills what is likely the last elk in Seattle, near Green Lake. The elk weighs 630 pounds.”, or 1893 when a cold spell froze the lake completely over. including  of Hydroplane boat races in the 1930s, as well as a cleanup and redesign in 1936.  Lots of history and evolution I won’t get into here, as it’d take days, but my favorite lost part of the Green Lake history, which I only discovered by accident after visiting the park many times, is the Aqua Theater, built in 1950 on the south edge of the lake as a 5,500 seat performance venue, built in a little more than two months coinciding with the first of what is now an annual Sea Fair.

The venue hosted a range of events included the annual Aqua Follies, which included ” Water ballets, diving exhibitions and clown acts took place in the pool and on the stage behind. Many of the Aqua Follies mermaids were recruited in Minneapolis before June 1, and began practicing before Seattle area college students finished their school term.”  There were some notable music shows including 1969, which featured Led Zepplin and The Grateful Dead, which was one of the final shows at the venue before it was shut down.

The lake as a locus for recreation has stayed consistent over the years, with lots of walkers and joggers circling the 3 mile loop, along with water access via boat rentals, rowing, and use of adjacent open spaces sports fields, and even a Par 3 golf course.  Water quality issues are a perpeutual issue, but it doesn’t stop it from being the busiest park in the state of Washington, with over a million visitors a year.

Postcard circa 1950s – via Seattle Greenlaker – https://www.seattlegreenlaker.com/2017/06/green-lake-seattle/


HEADER: 1987 Aerial view of Green Lake – via Seattle Public Archives

A recent article in the Denver Post “Denver accelerates “daylighting” of lost waterways, “undoing history” with decades-long re-engineering effort” discusses some exciting new work on restoring hidden hydrology and “Re-opening of buried waterways” in the area to manage stormwater runoff and create habitat.  The context:

“Old Denver pulsed with H2O, water that snaked through the creeks and irrigation canals crisscrossing Colorado’s high prairie before 150 years of urban development buried most of them or forced them into pipes.”

A similar story to many cities across the globe, “…developers focused on filling in creeks to make way for the construction of railroads, streets, smelters and housing — all laid out across a grid imposed on the natural landscape.”  This can be remedied today “…by reconstructing the urban landscape where possible, they’ll slow down water, filter it through vegetation to remove contaminants, control storm runoff and nourish greenery to help residents endure the climate shift toward droughts and rising temperatures.”

DENVER, CO – AUGUST 27: Newly planted grasses grow along Montclair Creek on August 27, 2018 in Denver, Colorado. The City of Denver is working on restoring the creek to help with future flooding. (Photo by RJ Sangosti/The Denver Post)

It’s heartening to see this large of a paradigm shift, and engineers, such as Bruce Uhernik, whom quoted saying:

“We’re just trying to take back that space and make waterways more natural and more beautiful. Why would people not want something to be more natural? This is being responsible — not just to what the city and people need, but to the environment’s needs. Birds. Fish. Trees that should be growing along these corridors. All these work in unison. If you break the chain, things fall off course.”

I appreciate some of the language, but the term “undoing history” is a bit strange to me as I always think of projects like this, in any form, as redoing history.  I guess it’s your take on what is history: the original pre-development condition that needs to be restored, or the interventions and filling as the history that needs undoing.  As mentioned, there’s plenty of history as “Historic Denver maps from the late 1800s show multiple irrigation canals and curving dotted lines denoting unnamed waterways, including a creek that flows through the Montclair Basin from Fairmount Cemetery toward north Denver industrial areas where smelting and rendering plants were located along the South Platte.”  

Either way, it’s a cool project, and has some unique components and context, much of which can be found in the Denver Public Works ‘Green Infrastructure Implementation Strategy‘, a document broad interventions for stormwater and habitat.  The prevalence of creeks is seen in the map of Recieving Waters (page 7) shows that while there are a number of urban creeks, they are impacted by residential, commercial, and industrial development throughout the region,

 

A series of maps in the report outlines pollutants of concern like Fecal bacteria and E.coli, Total Suspended Solids (TSS), Nitrogen, Phosphorous.  This map (page 21) shows subbasin level designations of Nitrogen, which is elevated by human activity, and can lead to algae blooms, and issues with aquatic species.

A focus on the urban core includes the Platte to Park Hill (Part of area 20 above (City Park/Park Hill), which integrates a number of systems.  As mentioned in the report:  “Stormwater Systems is taking a
comprehensive green infrastructure approach to better protecting people and property against fooding while improving water quality and enhancing public spaces.  Four projects are part of the Platte to Park Hill… Collectively, the  four coordinated projects will increase neighborhood connectively, add new park and recreation spaces, provide critical food protection, and improve water quality.” (page 54)  The Globeville Landing Outfall project is one of these segments, as part of the strategy, using open channel design, which “…will help clean storm water naturally when possible and will move the water to its ultimate destination, the South Platte River.”  A rendering of the plan:

The 39th Avenue Greenway (also seen in the header) also includes open channels for flood control and storm events.  The opportunity to layer community function with these facilities is key, as they are “…designed using a community-focused approach to provide the following benefits in addition to flood protection… “ which includes new open space, bike/walking trails, and more.  A rendering shows this integration.

An additional article from the Denver Channel provides a bit more perspective in video form on the Montclair Creek Project, including the “gray to green” approach “correcting past mistakes” focusing on the daylighted river weaving through a golf course and some more urban parts of the City, along with a greenway as mentioned above prior to outlet into the South Platte River.  The funds for the project, which were not insubtantial at $300 million, were voter-approved, with “daylighting of old waterways that were forced into pipes and buried during the industrial revolution in favor or streets, railroads and homes.”  


HEADER: Image of the 39th Avenue Greenway and Open Channel  – via the ‘Green Infrastructure Implementation Strategy‘ (page 55)

The Atlas for the End of the World is a great model for a compendium of research and mapping on a focused topic, which has relevance to my endeavor here at Hidden Hydrology.  While the content, scale and goals are different, the structure of information in the format of the ‘atlas’ and the combination of mapping, data, and critical inquiry through essay all resonate as a great precedent.

The project was conceived by Richard Weller from The University of Pennsylvania (UPenn), with collaborators Claire Hoch and Chieh Huang.  A summary of the project, launching in 2017, comes from the site:

“Coming almost 450 years after the world’s first Atlas, this Atlas for the End of the World audits the status of land use and urbanization in the most critically endangered bioregions on Earth. It does so, firstly, by measuring the quantity of protected area across the world’s 36 biodiversity hotspots in comparison to United Nation’s 2020 targets; and secondly, by identifying where future urban growth in these territories is on a collision course with endangered species.  By bringing urbanization and conservation together in the same study, the essays, maps, data, and artwork in this Atlas lay essential groundwork for the future planning and design of hotspot cities and regions as interdependent ecological and economic systems.”

Some background on the project is found in both Précis which provides a roadmap to the site, as well as an essay “Atlas for the End?” which alludes to the first modern atlas of Ortelius, the Theatrum Orbis Terrarum (Epitome of the Theater of the World) and the dawn of a new, albeit already populated, world, ready for exploration and exploitation.  As mentioned: “In 1570, when Ortelius published his atlas, the European imagination could literally run wild with whatever might be ‘out there’. Now, a mere 450 years later, that vast, mysterious world of diverse peoples and species is completely colonized and irreversibly altered by the material and conceptual forces of modernity. Whereas Ortelius marked out modernity’s territorial beginnings, this atlas—by focusing on the remaining habitat in the world’s 36 biodiversity hotspots —rakes over its remains.”

The extensive essay lays a formidable foundation for the research, touching on the impacts of the past 450 years and the loss of biodiversity through urbanization, and the identification of hotspots, as well as how cities play a huge role.  As quoted:

“Although it is not yet well monitored, it is increasingly appreciated that the metabolism of the contemporary city, no matter how divorced it might feel, is interconnected with the sources and sinks of the broader landscape. It follows then that environmental stewardship is as much a matter of urban design as it is landscape ecology. As Herbert Giradet insists, it is in cities “that human destiny will be played out and where the future of the biosphere will be determined. There will be no sustainable world without sustainable cities”.7

The themes touch on the foundations of the shift towards the Anthropocene, and our changing ideas about nature, stewardship, and it’s relationship to the profession of landscape architecture, touching on McHarg’s environmental ethics of the 1960s and also discussing the work of biologist Daniel Janzen and work on restoration of biodiversity using a metaphor of the garden.  “Janzen’s ‘garden’ is not an idyllic scene constructed for contemplation, nor does it trade in images of pristine wilderness. Wildland “gardenification” as he refers to it, is just damn hard work. As Janzen explains, it involves “fencing, planting, fertilizing, tilling and weeding … bioremediation, reforestation, afforestation, fire control, proscribed burning, crowd control, biological control, reintroduction, mitigation and much more.”36 Janzen’s garden is a continual work in progress.”

The ideas continue in discussions on the role of protected and connected ecosystems, and metrics, in this case, using the Convention on Biological Diversity (CBD).  From the text: “The overarching framework for the project of protecting and reconstructing a biodiverse global landscape is provided by the United Nations Strategic Plan for Biodiversity 2011-2020. The key mechanisms of this plan are brokered and administered through the Convention on Biological Diversity (CBD), one of the three ‘Rio Conventions’ emerging from the UN Conference on Environment and Development (the ‘Earth Summit’) held in Rio de Janeiro in 1992. The primary objective of the CBD is that “[by] 2050, biodiversity is valued, conserved, restored and wisely used, maintaining ecosystem services, sustaining a healthy planet and delivering benefits essential for all people”.   To this end, the focus on hotspots provides a locus for where these values intersect globally, as represented with ideas of protection (and lack there of) and the ability to access massive quantities of data collected through remote sensing and being able to map it using available technologies (while cautioning against the objectivity of mapping as a practice).

A concluding essay “Atlas for the Beginning” talks about the shift to our new reality of the Anthropocene.  A globe view shows “What’s left: the world’s protected areas as of 2015” which illustrates a bleak view of the fragility of the worlds ecosystems.  The takeaway is a research agenda that includes more data and analysis, as well as developing methods of action, including a  “…longer term research agenda is to establish a knowledge sharing network of demonstration design projects across the hotspots which bring landscape architects, environmental planners, conservationists, economists and local communities together to focus on areas of conflict between biodiversity and development. These SEED (systemic, ecological and economic design) projects will show how landscape connectivity can be achieved and how urban growth can be directed in ways that support all forms of life.”

The use of data visualizations, or datascapes, allows for unique comprehensibility of issues, as seen above. “The datascapes show that if the global population were to live (in material terms) as contemporary Americans do, there would be a major discrepancy between levels of consumption and what the earth, according to today’s technologies, can reasonably provide.” One such visual on Carbon Forest (below) shows the theoretical sequestration potential and equivalent size of forest to accommodate current populations, or, in actual numbers, “The 216 billion metric tons of CO2 emitted by a hypothetical global population of 10 billion such Americans would require 9.9 trillion trees to sequester its emissions. 2

The series of world maps are both beautiful and informative, spanning a range of topics both physical and social… a wide array of topics.

Each comes with a short blurb and reference.  The map on Ecoregions is described as: “The World Wildlife Federation defines an ecoregion as “relatively large units of land or water containing a distinct assemblage of natural communities sharing a large majority of species, dynamics, and environmental conditions” 1. An ecoregion is a biome broken down even further. There are 867 ecoregions comprising the world’s terrestrial and marine ecology. Nearly half of the world’s terrestrial ecoregions (391) are within the hotspots.”

 

Another interesting subsection is a feature Flora & Fauna, with “the photography of Singaporean artist Zhao Renhui, Director of the Institute for Critical Zoologists, from his 2013 artwork Guide to the Flora and Fauna of the World 1. The guide presents a catalogue of curious creatures and life-forms that have evolved in often unexpected ways to cope with the stresses and pressures of a changed world.”  The species are both amazing and somewhat disturbing, such as the bionic AquaAdvantage salmon (below), “…a genetically modified salmon that can grow to its adult size in 16 to 18 months instead of three years. The AquaAdvantage salmon has been modified by an addition of a growth hormone regulating gene from a Pacific Chinook salmon and a promoter gene from an ocean pout.”

Read more on the project via this post on the ASLA Blog, as well as a relevant article by Weller from the innaugural issue of LA+ Journal, entitled ‘World Park

All images and text: © 2017 Richard J. Weller, Claire Hoch, and Chieh Huang, Atlas for the End of the World, http://atlas-for-the-end-of-the-world.com 


HEADER:   Hotspot Cities: cities of 300,000 or more people projected to sprawl into remnant habitat in the world’s biological hotspots

An email from a reader of the site posed a few interesting questions about the two small lakes in the northern sections of Seattle, specifically discussing the current and historical outflows of these lakes.  I’ve discussed the small lakes in brief here, related maps of their bathymetry and tangentially in the context of Licton Springs. However, this was a good instigation to to focus on some more specifics of these urban water bodies.  I will refrain from my tendency to write another way-too-long post (of which this will inevitably turn into) and parcel this out in a few shorter ones, the first focusing on drainage questions (of which these are all connected) and then individual posts on Haller Lake, Bitter Lake, and Green Lake, as they are important parts of the hydrological history of Seattle.

To understand the overall configuration of water in Seattle, I did find this document by Seattle Public Utilities (SPU) titled ‘City of Seattle State of the Waters 2007‘. The first volume covers Seattle Watercourses, (which we will probably return to in the future), and in particular for our purposes here we look to Volume II: Seattle Small Lakes’  (both links above go to the PDFs – as I couldn’t find a page with a direct link) and it sounds like a great resource in need of an update.

For some general contents, a bit on lakes in general and their outfalls, from Vol. II, p.3:  “Lakes receive inflow from their surrounding watersheds through rivers, watercourses, overland and subsurface flow, and — in developed areas — from drainage pipes. Water typically exists a lake through a watercourse or river, although the outflows of most lakes in Seattle have been channeled into constructed drainage systems.”

HISTORIC DRAINAGE

In general, all three lakes are formed from Vashon glaciation, and as I mentioned previously, per geologist Stan Chernicoff, both Bitter and Haller lakes would be considered true kettle lakes, and Green Lake a hybrid, although still formed by glaciation.  The 1850s map locates the three Lakes, all of which are in the north portion of Seattle, but doesn’t offer too much in terms of drainage direction, aside from implying proximity between Thornton Creek drainage for Haller Lake, and Bitter Lake likely draining west due to proximity, neither show a visible outfall creek.

Green Lake it’s more obvious, with multiple inflows, including Licton Springs Creek, and the very distinct outflow that drains through Ravenna Creek southeast into Union Bay.

The 1894 USGS map offers us the aid of topography, along with a bit more more comprehensive creek coverage. Bitter Lake hints at the possibility of outfalls either direction, heading to the northwest down to ravines that skirt The Highlands and the Seattle Golf Club and outlet near Spring Beach, and also draining southeast towards a seasonal drainage. Haller Lake (titled Welsh Lake on the map) also has no visible outfall as well, but adjacent creeks that are part of Thornton Creek drainage nearby, and a wetland area to the south make me infer that these  would be like to be the natural drainage course of the lake.

Green Lake’s hydrology is a lot simpler to discern, with the similar inputs and outputs via the Ravenna outlet to the wetland zones near University Village and outlets into Union Bay.

TWO ALTERNATIVE THEORIES ON HISTORICAL DRAINAGE

One part I’ve always been a bit skeptical about in the USGS map is the location and extent of the drainage from Thornton Creek that looks to curve way west and intercept any south flow from the Bitter and Haller Lakes and direct it to the east to the larger Thornton Creek Basin.  Licton Springs Creek also flows south, and is in reality much further north than shown on maps, and the interface between the two basins if filled with springs and wetlands, so it’s likely there could have been some disconnect between what was there flowing south, and what was mapped flowing east.  However,  Alternative 1 uses the basis of the map as the correct flowline, so shows both Bitter Lake and Haller Lake draining towards a seasonal creek and wetland that exists in the South Branch of Thornton Creek, and a smaller drainage picking up Licton Springs Creek draining into Green Lake.  This mapped, overlaid on the 1894 map, shows an option for the lakes draining east, into Lake Washington. Dashed lines, for reference, are really basic watershed delineations, and the arrows show flow from lakes.

My gut is that both lakes flowed into Green Lake, via Licton Springs Creek, and then continued out to Ravenna.  Alternative 2 looks at a version of this where there is more of a distinct ridgeline separation between the Thornton Creek Basin and the drainage that flows north south, and that the survey misinterpreted the flowline that heads towards the east due to the aforementioned springs and wetlands.  The fact that the Licton Springs Creek is much further north than mapped, makes me posit that the upper lakes drained to this transfer point, and that instead of falling east, the flows kept going south into Green Lake, via the Licton Springs. Overlaid on the modern topography gives a bit of context to this configuration.

Both of these options are plausible, and the current outflows of the lakes (seen below) support this, with Bitter Lake draining to the Southeast and Haller Lake draining West.  This at least gives us the indication that these both flowed to the low north/south valley (where current Highway 99/Aurora Avenue runs), however, where they go after is still a bit of a mystery. My follow-up plan is to look at some Lidar or a DEM to provide a much clearer picture of the flowlines and ridgelines, which we can assume, much like the current topo, is mostly similar to its predevelopment configurations (i.e. places in Seattle where we didn’t move hills).  This will go beyond this back of the napkin approach above and see if that higher degree of detail unlocks any new info.

CURRENT DRAINAGE
While it’s hard to determine the exact nature of pre-development drainage on these lakes, we can infer much from these historic documents and topography.  The current system is more clear, although not visibly inherent due to the modernization and piping of drainage through large intercepter sewers – in this case the Densmore Avenue Drainage System, which runs north/south around the low flowline at Aurora Avenue (Highway 99).

The first hint of the split of drainage is in the State of the Waters, where both Bitter Lake and Haller Lake fall outside of their adjacent drainages going west to Piper’s Creek and east to Thornton Creek.  Figure 1 from the report shows a narrow band that is bisected by this linear north south zone, with both creeks located inside the boundary.

A search for the nature of this basin configuration is somewhat frustrating, mostly as it seems to be specifically not related to a creek so isn’t referenced as a watershed in the same way.  The SPU site on Urban Watersheds breaks down the city into four distinct areas of drainage, including the Puget Sound, Lake Washington, and the Duwamish River, as well as this uniquely land-locked zone we’re focused on, known as the Ship Canal/Lake Union basin

This is subdivided into some smaller sub-basins,including the Ship Canal Basin, the South Lake Union, and our zone, the North Lake Union Basin, which stretches up to the northern lakes, in that same narrow band, encompassing their drainages, then around Green Lake, and south to the interface with Lake Union.

The specific acrobatics that the Densmore Basin does to get down to Lake Union is hinted at but there’s not a lot of great maps, in particular the last section which .  This excerpt from the Seattle Comprehensive Plan Update Draft EIS from May 4, 2015 shows the ‘capacity constrained’ condition. but does highlight the basin and it’s

I dug a bit more and found another mystifyingly badly interfaced GIS portal, this time Drainage Basins layer from City of Seattle, embedded below.  Again, need to download the data and have a bit more freedom to sort it out in order to display it in a better way, but you get the idea from this map (especially if you zoom in on the areas below Green Lake, and can see the basin outline snaking in a thin, gerrymandered strip beside I-5.

 

The lakes themselves fit within the infrastructure systems, as seen below.  The City of Seattle Water and Sewer Map , which I thought would be helpful but really isn’t because you have to zoom way in to show pipes and so lose context, so it  doesn’t clearly articulate the drainage system elements enough to isolate (i included a few screenshots), so probably need to get some GIS files to draw these and separate mains, branches, etc. to isolate systems, but the narratives are pretty clear in explaining the outfall scenarios.

Haller Lake, which is around 15 acres of drainage, and has a maximum depth of 36 feet, get’s inputs from adjacent residential drainage areas (280 acre drainage), now drains via the Densmore system, as mentioned in State of the Waters, Vol II, the lake “…discharges through an outlet control structure on the western side of the lake, eventually draining to Lake Union via the Densmore storm drain system.”

Bitter Lake, measures 18.4 acres with a max depth of 31 feet, draining a smaller area (159 acre drainage). This lake is also being drained into the Densmore system, from the State of the Waters, Vol II, page 25: “At its southeastern end, Bitter Lake drains through a piped outlet that runs through a series of small ditches and culverts before entering the Densmore storm drain system on Aurora Avenue North.  The Densmore system is equipped with a low-flow bypass, which conveys runoff directly to Lake Union. Under high-flow conditions, runoff passes through Green Lake before discharging to Lake Union.”

Green Lake, has a surface area of 259 acres, and a shallow depth, maxing out at around 30 feet, drains a basin of 1875 acres of surrounding area, as well as getting inputs from the Densmore system, as mentioned above.  Alas, it now no longer drains into Ravenna Creek, but is diverted, per the State of the Waters, Vol II, and“now discharges to Lake Union through a single outlet located near Meridian Avenue North.  In the past, Green Lake also discharged to the combined sewer system via a number of outlets around the lake. However, these outlets were recently blocked and now are used by Seattle Parks and Recreation only during rainstorms of long duration when the Meridian Avenue North outlet is not adequate to maintain water levels in Green lake.”

 


HEADER: Haller Lake from above – via Windemere

 

 

I tweeted a bit back that I’m reading the book Rivers Lost, Rivers Regained: Rethinking City-River Relations, and so far it hasn’t disappointed.  More info for sure on some of the great content on cities and rivers forthcoming. However, an intriguing  concept mentioned in the intro was the Japanese concept of shin-sui, which the authors loosely define as “playing with water”.  They mention these in an overall trend of cities refocusing on their urban rivers, and specifically of ways to encourage people reconnecting with these urban waterways. The authors bring up urban waterfront parks, and mention these “shin-sui” parks as a way of connecting with natural processes:

” “Although these projects were conducted for recreational rather than ecological purposes, they helped to turn people’s eyes back to nature.”  (18)

Translation being a tricky thing, there’s multiple meanings that emerge when one starts digging into the concept of shinsui (and someone with a grasp of Japanese beyond my total lack thereof please correct me).  Online definitions, include water references, summarily – flood, fuel & water, inundation, as well as having meanings for adoration, cooking, salary.

Another reference in a book that popped up in a Google search, Japan for Kids, has a great way of describing the parks a friendship: “A new concept in neighborhood playground is a ‘shinsui park.’  Shinsui means literally ‘to be friendly with water.’ A shinsui park is one with plenty of water attractions that provide children with a chance to get use to water by playing in it.” (127)

The designs for these transcend the mere “splash play” or water park, but do share some of the same elements of interactivity and immersion.  Owing to the diversity of density of Japanese cities, they are often narrow, but it does show the potential for even abstracted water courses to co-exist with urbanization.

Otonashi Shinshi Park is one of these very urban examples, located in the northern area of Tokyo and literally wedged in a channel between development.  You get a feel for the scale and elements, in this case a high-walled channel that opens up to some more interactive and tactile elements.

A little more lush version from photographer Andy Serrano is found at Oyokogawa Shinsui Park, which he describes: “The park runs alongside the Oyoko-gawa River in the Sumida Ward of Tokyo, and is a popular place for local residents who play, walk, fish, and even swim there. With the Tokyo Sky Tree looming nearby, cherry blossom season gives visitors a taste of Japan’s dual natures: historic traditions side-by-side with ultra-modernity, natural beauty next to futuristic technology and architecture.”

The Tanada Shinsui Park on the Houzuyamma River in the village of Toho in Fuuses some vernacular elements to create a “River pool…for the infant and elementary school children [and the] …”Koinobori pool” river pool is a pool that uses the difference in height of the rice terraces.”

Another urban example is sculptural pools of the Arima River Shinsui Park near Kobe, Japan, which is located near Arima Onsen, one of the oldest hot springs locations in the country.

As mentioned, these few examples I’ve show are not about restoration, and vary from just parks by the river to ones with active recreation elements focused on water.  While natural edges occur, many are somewhat channellized, highly designed and very abstracted river environments — akin the art-side of the conceptual continuum of restoration.  The goal here is more recreational, but, as the editors of Rivers Lost mention, they may provide a powerful precedent for engaging people of all ages with their natural waterways, and informing urban residents on the natural processes

 


HEADER: Otonashi Shinsui Park – Tokyo, via Japan by Web