Daylighting Rivers

    by Sally Cole

    Daylighting:  A Global Trend Transforming Cities in the 21st Century

    Waterways were once the lungs and arteries of urbanization.  Yet, most of the world’s cities have buried their founding streams under concrete or incorporated them into sewer networks under roads and expressways and housing and industrial developments.  Burying rivers has degraded habitats and increased pollution and the costs of water treatment and waste management.  It has also increased flooding and damages due to flooding that are increasing with climate warming.

    What is Daylighting?

    Daylighting is the process of removing concrete and culverts that are covering and obstructing original rivers, creeks and drainage paths and of revitalizing original wetlands and drainage flow.  Daylighting is part of a larger flood management and water treatment strategy and an attempt to redress the thoughtless neglect of cities that continue to pollute their rivers.

    Why Daylight?

    Bringing back lost urban rivers by removing culverts and integrating flowing rivers into cities again –daylighting – is part of a global movement to rediscover urban rivers in cities worldwide.  In the 21st century, forward-thinking cities and citizens – in London, New York, Seoul, Zurich, Berkeley – are daylighting their historic rivers in a bid to halt pollution end environmental degradation, and increase the liveability and future viability of their cities.

    These cities report that their daylighting projects have:

    – reduced water treatment costs

    – aided flood management

    – increased property values

    – revitalized natural habitats with the return of indigenous plants, trees, fish, birds    and other wildlife

    – added greenbelts, bike routes and walking paths that have produced connectivity within and between neighbourhoods

    – increased social health and volunteer citizen engagement;

    – created tourism and related business opportunities.

    Montreal has an opportunity to join this progressive urban trend and invest in the future of our city by daylighting our historic St. Pierre River, the river on which our city was founded.

    The Lachine Canal bike path crosses where the bed of the St. Pierre used to be.

    Models of Successful Daylighting in Cities Around the World

    Since 2009, London has opened up more than 17kms of waterways.  Throughout the U.K. – where daylighting is known as deculverting — municipal governments have incorporated deculverting into legislation on water and flood management.

    Zurich, which has undertaken more daylighting than any other city in the world, has tracked, documented and analyzed the combined social, environmental and economic benefits.  The city has found the economic rewards of daylighting in reduced wastewater treatment costs.  Channeling clean water out of sewers and back into original rivers and streams reduces the volume of water that flows to sewage waste management facilities for treatment.  Zurich also reports an increase in public desire and civic engagement to recapture lost spaces and to improve the quality of life in the city.

    The daylighted Cheonggyecheon Stream in Seoul, South Korea, transformed a polluted, urban, crime-ridden wasteland into a major flood relief channel and a 10.9km public downtown recreation space that has revived the city centre and attracts more than 60,000 visitors each day.  Restoration of two historic bridges over the restored river, along with managed changes in the downtown traffic system, has reduced by 2.3% the volume of cars entering downtown Seoul each day and increased bus and subway use.  Along with reducing air pollution, daylighting the Cheonggyecheon has created an environment with clean water and natural habitats that also helps to cool temperatures in the downtown area to 3.6 C lower than other parts of Seoul.

    Daylighting the Sawmill River in Yonkers, New York, has created a vibrant green corridor in the city and revitalized the downtown.

    In an effort to reduce future flood risk, after hundreds of basements flooded in a 1999 storm, the city of Dubuque, Iowa invested in an engineering study.  The key recommendation of the study was to restore, through daylighting, a one-mile section of the buried Bee Creek that flows under the city centre.

    To manage frequent flooding in the downtown area of Kalamazoo, Michigan, city engineers found that it was cheaper to daylight the buried Arcadia Creek than to rebuild and expand the century-old culvert system.

    Friends of Meadowbrook Are Daylighting the St Pierre River!

    The first step in daylighting is to map the route and extent of a buried river under the city.  The route of the St Pierre River is well known — from its source on Mont Royal through its various tributaries and down to its original outlet into the St. Lawrence River at Pointe-à-Callière.

    The St. Pierre River in 1834. source: carte de l’ile de Montreal, 1834, by A. Jobin, BAnQ

    The next step in daylighting is called cultural restoration of the river.  Cultural restoration celebrates a buried river through markers, public art and activities to inform the public of its historic path and ecological role, and to raise awareness of the environmental issues and economic costs that have been created over time.

    In the case of Montreal, the city has buried the St Pierre River and channelled it into its sewage system until only 200 metres of the original river remain above ground today – in the Meadowbrook golf course.  And those 200 metres are severely polluted through the continued crossing of sewage and floodwater pipes.  Members of Friends of Meadowbrook have begun the work of cultural restoration of the St Pierre River by organizing an annual bike ride along the river’s route from Meadowbrook to Pointe-à-Callière.

    The ultimate goal of daylighting is natural restoration: to revitalize some or all of a river to recreate its original ecology and habitats and its rightful place as the centrepiece – the lungs and heart — of a community.

    The St Pierre River

    by Sally Cole

    Montreal owes its location to the St Pierre River.  The history of the city and the river are deeply intertwined.

    When Samuel de Champlain arrived in 1611, the river teemed with fish.  Game birds nested along its shores.  Strawberries, fruit trees and nuts thrived.  The rich river habitat had, for millennia, offered indigenous peoples a healthy diet and food security as they hunted, fished, gardened and traveled along the river.

    The river provided access to, and shelter from, the mighty St Lawrence and Ottawa Rivers.  The original inhabitants had cleared more than 60 acres of land by the St Pierre River where they were growing corn, beans and squash when Champlain chose these cleared meadows, now the site of Place Royale.

    The meadows proved fertile for European farmers and settlement grew. The site was to prosper as a hub in the North American fur trade and as a port for lumber export to Europe.

    In the 19th century, the St Pierre River offered waterpower for mills and tanneries, propelling Montreal’s industrial development and the city’s emergence as a major commercial and finance centre. Serving as the city’s first sewers, the river also gave itself to assist in managing public health and sanitation as population density and industry increased.


    The St Pierre River is one of more than 30 rivers and streams that once traversed the Island of Montreal. It traveled from its source on Mount Royal via several tributaries to Cote St Luc, Ville St Pierre, St Henri and Verdun to Pointe à Callière in Old Montreal and Angrignon Park in Lasalle.

    It flowed over the Notre Dame de Grace (now St. Jacques) Escarpment, draining the higher ground and widening into a lake below that was once called Lac St Pierre, and later called Otter Lake, now the site of the Turcot highway expansion project.

    Early Changes to the River’s pathways

    As settlement grew north and west along the river’s banks, the waters of Otter Lake were gradually drained and diverted to supply mills downstream and to build canals to bypass the Lachine rapids.

    The first brick sewer, the William Collector, was built at the mouth of the river in 1832-38.  An engineering feat in its day, it can be visited today at the Pointe-à-Callière Museum located on the site. Throughout the 19th century, the industrializing city straightened, dredged and diverted the St Pierre River as it built the city waterworks, supplied steam engines to drive industry, and integrated the river into an urban sewer system. By the mid 19th century, when the first railway yards were built, Otter Lake was a marsh (that later swallowed two locomotives).

    By the early 20th century, more than one third of the river had disappeared into sewers.  In the 1930s the city built two giant concrete conduits in the St Pierre River to collect Westmount waste and carry it away through Cote St Luc and Verdun for eventual treatment in the east end.

    In the 1950s, sewer construction for new housing in the suburb of Cote St Luc covered open sections of the Little St Pierre tributary and the Cote St Luc plaza was built on a wetland of the original St Pierre river drainage. In fact, Andrew Emond, a Canadian photographer, has explored and documented the evolution of the underground system of the river in a fascinating series of photos, maps and commentary. (See )

    That even 200 metres of the Little St Pierre River survive today is only because this tributary of the St Pierre River was a key feature of the 57-hectare recreational park Canadian Pacific Railway created for its workers in 1917 which became the Meadowbrook golf course in 1949.

    Fast track to the 21st century

    In 2010, real estate developer Groupe Pacific (GP) submitted a proposal to the city of Montreal for “The Petite Rivière Project.”

    Action #1 was to:  “Bring the distressed Petite Rivière stream back to life as a healthy, restored river.”  In its original proposal, the developer stated that GP itself would purify the river through a system of reed beds and shallow ponds (like Central Park the GP proposal boasts!) to manage rainwater and snowmelt and to bring back the biodiversity of the river’s habitat for amphibians, birds and small mammals.  The regenerated river and wetlands would become the centrepiece of a new park — “The Petite Rivière Park” –for the new residential community.

    But today GP refers to the Little St Pierre River as a “smelly ditch” and has sued the City of Montreal, demanding that the “open sewer” be buried.  We are now a long way away from Groupe Pacific’s proposal to make the Little St Pierre River the centerpiece of its real estate development!

    Importance of the River Today

    Although only 200 metres of this historic river system survive, the St Pierre River continues to play a defining role in public debate about the future of Montreal and the kind of city we want to live in. Beyond its historic and cultural importance, the river is a site of past and potential biodiversity, a preserve of century-old trees and a sanctuary for migrating birds.

    The St Pierre River drainage also has an important role to play in future rainfall, ice melt and flood control.  Climate change is increasing the number of extreme weather events like storms and floods. Wetlands and riverbanks are an economical, clean and natural means to help manage rainfall and flooding

    Many of the world’s great cities including Seoul, Paris, New York, London and Toronto are working to bring back — they are “daylighting” — their original rivers, streams and wetlands. These cities recognize that it is crucial to use their underground rivers and wetlands to manage increasing drainage problems in the face of the rising frequency and scale of flood events.

    They also know that clean streams, rivers and wetlands within their cities add measurable value to real estate and immeasurable aesthetic pleasure, educational opportunities and health and well-being to residents.


    Pollution: Causes & Solution

    The pollution today in the St Pierre River is a relic of Montreal sewage practices in the last century. The river is polluted because Cote St Luc and Montreal West have allowed crossed sewage and drainage pipes to mix household waste and storm water. 

    The solution in 2018 is to correct the problem: to separate this sewage and storm drainage system in order to CLEAN the St Pierre River — NOT to bury the river and pave over it as a 19th century city would have done.

    Let’s Clean and “Daylight” the St. Pierre River

    Let’s Keep the Brook in MeadowBROOK!


    The film Lost Rivers by Montreal director Caroline Bacle explores the phenomenon of daylighting:

    Gazette journalist Marion Scott also covered the River extensively in 2009

    See also “At the mouth of Riviere St. Pierre during the early stages of Montreal in1700” and “Approximate path of river, circa 1800” in

    photos by Nigel Dove






    Will Meadowbrook lose its brook?

    Montreal, June 29, 2018–Following a decision by Judge Chantal Corriveau of the Quebec Superior Court (file 500-17-079150-135) of June 7, the court “ORDERED the City of Montreal to obtain from the ministère du Développement durable, de l’Environnement, et de la Lutte contre les changements climatiques a certificate of authorization to undergo work to put a stop to the pollution of the Meadowbrook stream in a maximum of four months from the present decision. The City is to have completed said work in a maximum of 18 months and further proceed to decontaminate the banks of the said stream in a maximum of 24 months from this decision”. (Our translation)

    The rehabilitation of a stream sounds like good news. The stream in question is in fact one of the few sections of the historic St. Pierre River still visible in Montreal.

    The St. Pierre River likely took its source on the western slope of Mount Royal. It then flowed into St. Pierre Lake (dried up with the creation of the Lachine Canal) to finally reach the St. Laurence River in Verdun. It was diverted to the Little St. Pierre River (on which the French colonists settled at Pointe à Callières) in the 18th century to power some watermills. It was finally buried in the Montreal sewer system in the 19th century, being far too polluted.

    Two centuries later, history repeats itself. While many cities around the world are daylighting lost rivers, Montreal might well be forced to cover what is left of the St. Pierre River because it is too polluted and time is of the essence to remedy the situation.

    Just where does that pollution come from? Likely from a Montreal storm sewer that is being contaminated from cross-connections in some 200 buildings located for the most part in Montreal-West and Cote St. Luc according to the City of Montreal.

    The case has been before the courts since 2013 when the owner of Meadowbrook, Meadowbrook Groupe Pacific, filed an injunction to “force Montreal to stop the contamination by capping the stream or by any other mean that would have a comparable result”. Montreal has tried to join Montreal-West and Cote St Luc to the suit but this was refused by the court. This last decision practically spells the demise of the river.

    Groupe Pacific bought the 57 hectares of Meadowbrook in 2006 for $3 million, a sum reflecting the thwarted efforts of the preceding owners, Canadian Pacific Railway and its subsidiaries, to develop the land. With this latest decision, Groupe Pacific will have its land decontaminated at the expense of the taxpayers, which will increase its value and increase the area, the developer having gotten rid of the river that runs through it.

    The MDDELCC should not allow the City of Montreal to bury the river. The whole land plays a pivotal role in absorbing spring runoff and rainfall and provides a welcome respite to migrating birds. With the reduction of the wetlands in the Technnoparc in St. Laurent and work on the Turcot exchange near the St. Jacques escarpment, here is another area on the migratory bird flight plan to be destroyed.

    For more information:

    Louise Legault, director, Les Amis du Parc Meadowbrook