Category: Water and Environment

The relationship between water and biodiversity is not a one-way street.  The Global Biodiversity Outlook found that “biodiversity is directly implicated in maintaining most ecosystem functions that deliver [water-related] services, but it is also a co-beneficiary of improved ecosystem conditions”¹.  Biodiverse ecosystems tend to manage water well because of their biodiversity, while simultaneously, landscapes with consistent and available water tend to support a higher degree of biodiversity.   

One of the most apparent markers of rich biodiversity in a landscape is the presence of water.  While in some cases the presence of water is obvious and significant, such as rivers, oceans, lakes, and streams, even large plant leaves collecting a few droplets of dew or a small depression filling with water after a rain can have a significant impact on the presence of wildlife nearby.   

The quality of available water in a landscape is directly tied to biodiversity.  As mentioned above, biodiverse ecosystems tend to manage water well, and in this case, biodiversity can create the conditions necessary to maintain water quality.  In this way, biodiversity performs an ecosystem service that is self-regulating, and can benefit humans as well.  Reduction of biodiversity can have a negative effect on water quality, which in turn drives further loss of biodiversity.  For more information on water quality, please visit the Water Quality blog page. 

The different states and conditions of water also impact biodiversity.  For further information, please visit any of the following ecosystem-specific blog pages: Wetlands, Intertidal Zone, Lotic Ecosystems, Lentic Ecosystems, and Riparian Zones. 

[1] Secretariat of the Convention on Biological Diversity, “Water and Biodiversity.”

As environmental designers reimagine land use in the decades to come, we have a significant responsibility not just to reduce harm, but also to revitalize landscapes for biodiversity, both through large scale planning and conservation measures, as well as through smaller interventions and networks.  Since we know that biodiversity and water are intricately co-dependent, improvements to water quality and systems must occur as an integral part of all efforts to increase or safeguard biodiversity.  Understanding how to maximize biodiversity within the scale and constraints of a project through water is a helpful starting point.  Here is a selection of considerations: 

Research, and work with experts on local plants, animals, and ecology to develop water-based plans that respond to site-specific ecological needs.  

Understand what is beyond the site.  Both water and life are almost never confined to a project site, so understanding water regimes (see the Watersheds blog page) as well as large-scale ecosystems that surround a site is a critical part of integrating into a network of biodiversity, especially with limited-impact small-scale projects. 

Add and improve sources or collection points for water in designed landscapes, one of the most impactful moves to increase or maintain local biodiversity.  This can occur across scales, from adding plants that collect dew droplets for insects in an urban front yard, to daylighting streams or planning city-wide networks of rain gardens (see the Rainwater Management blog page).   

Improve water quality.  Often, biodiversity loss in aquatic or near-aquatic ecosystems is related to degradation of water quality.  Starting with water quality ensures that biodiversity increases can be sustained by that which it relies on, while finishing with ecology ensures that the new level of water quality can be maintained.  

Provide regulated access to watery ecosystems.  While the presence of humans may not seem like a key factor in increasing biodiversity, providing safely considered access to biodiverse ecosystems, along with educational programs, can help people experience firsthand the importance of a landscape and of biodiversity, prompting future generations to care better for the land around them. 

Secretariat of the Convention on Biological Diversity, “Water and Biodiversity: Summary of the Findings of the Fourth Edition of the Global Biodiversity Outlook as They Relate to Water,” 2015, https://www.cbd.int/gbo/gbo4/gbo4-water-en.pdf

“What Is the Human Impact on Biodiversity? | Royal Society.” https://royalsociety.org/topics-policy/projects/biodiversity/human-impact-on-biodiversity/.

Images

Figure 1: Jones, Adam. “Disruption to Tiny Life Can Lead to Big Changes in Warmer Climate.” University of Alabama News (blog), October 12, 2020. https://news.ua.edu/2020/10/disruption-to-tiny-life-can-lead-to-big-changes-in-warmer-climate/.

Burke Mountain Naturalists. “Field Trip to Reifel Bird Sanctuary May 2017,” May 31, 2023. https://www.burkemountainnaturalists.ca/photos/field-trip-to-reifel-bird-sanctuary-may-2017/.

Landezine. “Dr. Stephan Brenneisen: Living Roofs – Biodiversity and Water Retention by Design Measures.” https://landezine.com/dr-stephan-brenneisen-living-roofs-biodiversity-and-water-retention-by-design-measures/.

A video lecture that focusses on methods for creating biodiverse green-roofs.

Brezar, Zas. “The Cute, the Bad and the Ugly – On Urban Biodiversity and Ecological Aesthetics.” Landezine. https://landezine.com/the-cute-the-bad-and-the-ugly-on-urban-biodiversity-and-ecological-aesthetics/.

An opinion piece that outlines the relationships between biodiversity and the aesthetics of designed spaces in urban centers.

xʷəyeyət / Iona Island is an extensive re-imagination of Vancouver’s waste water treatment facility and the surrounding landscape that aims to remediate ecological, geological, and cultural harm done by previous alteration to the landscape.

Project can be viewed here.

Pollinator Passages: ByBi, multiple community participants
Oslo, Norway

A community-led initiative, pollinator passages aims enlists “urban dwellers, professionals, neighborhoods, municipal agencies, organizations and businesses to help create good habitats and thriving routes for pollinators across the entire city” of Oslo. Variably scaled interventions and helpful resources make this initiative easy for many to participate in, helping to restore this critical aspect of biodiversity in a growing urban center.

This project can be viewed here and here.

Wetlands are areas in which the land is submerged in water, whether it be seasonally or permanently, and are differentiated by their hydric soils and hydrophytic vegetation. The plants within wetlands have special adaptations that allow them to flourish in the saturated environment, including floating leaves, waterlogged stems, and oxygen transport systems¹. Due to frequent soil saturation, wetland plants have roots that are located in the upper zone, or within 30cm of the soil surface, a response to anaerobic conditions created by waterlogging². The hydric soils are critical in managing the water balance within wetlands as they retain water and release it over time³.

There are various hydrological descriptors for wetlands, as they can be categorized by their flood duration, their flow of water, and by their salinity, influenced by groundwater flows. The flow of the water can be broken down into inflow (in which water comes in and does not leave), outflow (water flowing out), throughflow (water flowing in and out), and bidirectional flow (flux in water levels due to tides or levels of a nearby waterbody)⁴.

[1] Eyvaz and Albahnasawi, Wetlands – New Perspectives.

[2] Tiner, “Wetland Hydrology.”

[3] Eyvaz and Albahnasawi, Wetlands – New Perspectives.

[4] Tiner, “Wetland Hydrology.”

While wetlands have different classification systems, one classification system breaks them down into three general categories: inland wetlands, coastal/marine wetlands, and human-made wetlands¹.

Inland wetlands: rivers/streams, lakes, peatlands, marshes/swamps, forested wetlands, groundwater-dependent wetlands, vernal pools

Coastal/marine wetlands: estuaries, mangroves, seagrass beds, coral reefs, shellfish reefs, coastal lagoons, kelp forests, etc.

Human-made wetlands: reservoirs, agricultural wetlands (rice paddy, palm oil plantations, wet grasslands), wastewater treatment and constructed wetlands, saltpans, aquaculture ponds, etc.²

An overview of the various wetlands within Canada as well as a description of the key categories (bog, fen, swamp. marsh) can be found here.

[1] Gardner and Finlayson, “Global Wetland Outlook.”

[2] Gardner and Finlayson.

Wetlands provide great value to society in through a range of crucial functions, including the following:

Flood control and erosion. This is provided by their ability to retain and release water, which is especially important during times of increased precipitation, where their sponge-like nature allows them to hold water and release it during times of low precipitation.  

Maintenance of water quality. Wetlands purify water, working as a filter to remove sediments, excess nutrients, and contaminants.

Provision of wildlife habitat. Wetlands provide habitat for many animals, especially many species of birds, including shorebirds and migrating birds who stop to rest and feed there.

Sequestration of carbon. Wetlands act as a carbon sink, storing a large amount of carbon in their soils and vegetation¹.

Role in biogeochemical cycles. Beyond their role in carbon cycles, wetlands also store nitrogen, phosphorus, and metals, which are retained through the wetland’s sedimentation processes. These chemicals may also be transferred to surrounding ecosystems through their hydrologic pathways².

[1] Gardner and Finlayson.

[2] Faulkner, “Urbanization Impacts on the Structure and Function of Forested Wetlands.”

Historical rates of wetland loss were much higher than current rates as they were often drained and used for other purposes, without a full realization or consideration of the range of ecosystem services they provided. Today, wetland loss is especially prevalent in developing countries as population growth and increased agricultural production. While there is a greater understanding today of the value of wetlands, many anthropogenic factors still impact them, including^1,2:

Sea level rise. A rise in sea levels will cause an increase in salinity due to saltwater intrusion in coastal wetlands, which will impact the vegetation that is able to grow and thrive there.

Urban development. An increase in impermeable surfaces and storm drainage, among many other changes including the quantity and quality of water that flows in and out of wetlands, as runoff carries pollutants into surrounding water bodies.

Deforestation. As deforestation increases erosion, there is an increase in the transfer of sediments to wetlands, ultimately damaging the ecosystems³.  

Agricultural land use. Runoff from urban or agricultural areas brings with it pollutants or nutrients which then flow into adjacent areas. The excess of nutrients leads to eutrophication, potentially altering the plant community composition and/or producing algal blooms that degrade water quality and further affect plant and animal species that rely on the wetland habitat⁴.

Invasive species. They have the potential to outcompete native plant species, affect nutrient cycling, and alter the ecosystem and soil regime⁵.

[1] Keddy, “Causal Factors for Wetland Management and Restoration.”

[2] Gardner and Finlayson, “Global Wetland Outlook.”

[3] Gardner and Finlayson.

[4] Ward, “Wetlands Under Global Change.”

[5] Ward.

Given the many benefits provided by wetlands, it is important to take efforts towards wetland conservation. With climate change and its resulting impacts, a critical measure that can be taken to protect cities from sea level rise, flooding, and droughts is to integrate wetlands into the environment as a means of water storage and purification. The IPPC report for policymakers reiterates this stating that “ecosystem-based adaptation approaches such as urban greening, restoration of wetlands and upstream forest ecosystems have been effective in reducing flood risks and urban heat”¹. While the knowledge of the importance of wetlands is becoming widespread, it is critical that cities and regions start and/or continue to include wetland preservation within their management plans.

[1] IPCC, “Climate Change 2023 Synthesis Report.”

Eyvaz, Murat, and Ahmed Albahnasawi, eds. Wetlands – New Perspectives. Vol. 7. Environmental Sciences. IntechOpen, 2023. https://doi.org/10.5772/intechopen.104315.

Faulkner, Stephen. “Urbanization Impacts on the Structure and Function of Forested Wetlands.” Urban Ecosystems 7, no. 2 (June 1, 2004): 89–106. https://doi.org/10.1023/B:UECO.0000036269.56249.66.

Gardner, Royal C., and C. Finlayson. “Global Wetland Outlook: State of the World’s Wetlands and Their Services to People,” October 5, 2018. https://papers.ssrn.com/abstract=3261606.

IPCC. “Climate Change 2023 Synthesis Report,” 2023. https://www.ipcc.ch/report/ar6/syr/. https://doi: 10.59327/IPCC/AR6-9789291691647.001

Keddy, Paul A. “Causal Factors for Wetland Management and Restoration: A Concise Guide.” Springer 8 (2023). https://doi.org/10.1007/978-3-031-21788-3.

Tiner, R.W. “Wetland Hydrology.” In Encyclopedia of Inland Waters, 778–89. Elsevier, 2009. https://doi.org/10.1016/B978-012370626-3.00018-1.

Ward, Eric J. “Wetlands Under Global Change.” In Encyclopedia of Inland Waters, 295–302. Elsevier, 2022. https://doi.org/10.1016/B978-0-12-819166-8.00142-0.

Urban Design Wetland Guide – The aim of this guide is to provide comprehensive and practical advice on the design and maintenance of constructed wetlands for the purpose of mitigating urban diffuse pollution. It is based on the London Borough of Enfield’s track record of delivering urban wetlands in a variety of settings.

Riparian zones foster high biodiversity of plants which in turn provide a myriad of contributing habitat functions such as pollen, shelter, and resting sites for migratory species, among many other functions. They also retain and filter nutrients from upland areas, serve as areas of organic matter recycling and carbon sequestration, provide sediment detention, thermal regulation, and bank stabilization.¹ They also transfer plant litter to streams and rivers, which ultimately gets decomposed and subsequently used in the aquatic food web.²

There are multiple hydrological factors influencing the riparian zone: river flow, groundwater upwelling, rainfall, and surface runoff. The riparian vegetation is largely dependent on the availability of water, and therefore changes in the hydrology, especially of river flow, will directly impact the vegetation.³

[1] Merritt, “Riparian Zones.”

[2] “Riparian Landscapes – ScienceDirect.”

[3] “Riparian Landscapes – ScienceDirect.”

Flow regulations, the introduction of pollutants, change in climate, and altering land use are the primary anthropogenic influences impacting riparian zones. Flow regulation includes the construction of dams, the channelization or dredging of the water body which lowers the water table and thus alters the composition of species, and levees which separate rivers from floodplains.¹

[1] Décamps, Naiman, and McClain, “Riparian Zones.”

It is important that the connection between the riparian zone and in-stream habitat is maintained, and that this relationship be viewed at the watershed scale, as opposed to local scales. This approach allows for interactions along different habitat zones, along the continuum of rivers, and between atmospheric water and ground and surface water. As noted by Tomer, various water quality concerns within a watershed may be solved by appropriate riparian zone management as they are adjacent to waterbodies and greatly affect the sediments, pathogens, temperature, and algae present within these waterbodies¹. Management of riparian zones includes maintaining vegetation over the soil, protecting the diversity of plants, removing invasive species, among other practices that can be found here².  

[1] Tomer, “Watershed Management.”

[2] Ministry of Agriculture and Food, “Management of Riparian Areas – Province of British Columbia.”

396–403. Elsevier, 2009. https://doi.org/10.1016/B978-012370626-3.00053-3.

Food, Ministry of Agriculture and. “Management of Riparian Areas – Province of British Columbia.” Province of British Columbia. https://www2.gov.bc.ca/gov/content/industry/agriculture-seafood/agricultural-land-and-environment/water/riparian-areas/management.

Merritt, David M. “Riparian Zones.” In Encyclopedia of Inland Waters, 276–89. Elsevier, 2022. https://doi.org/10.1016/B978-0-12-819166-8.00177-8.

“Riparian Landscapes – ScienceDirect.” https://www.sciencedirect.com/science/article/abs/pii/B9780128225622000578.

Tomer, M.D. “Watershed Management.” In Reference Module in Earth Systems and Environmental Sciences, B978012409548909117X. Elsevier, 2014. https://doi.org/10.1016/B978-0-12-409548-9.09117-X.

Along with changes in the presence and absence of water, the intertidal zone is characterized by shifts in salinity, temperature, and movement.  

Salinity: Evaporation of water at the upper intertidal zone increasing the salinity, while precipitation inversely decreases it¹.  

Temperature: The regulating effect of water on temperature influences the habitability of the intertidal zone.  While low intertidal zone organisms benefit from more consistent inundation and tend to be more sensitive to temperature change (eg, coral reefs) organisms in the high intertidal zone must be especially resilient to temperature swings.  in coastal British Columbia in 2021, very low tides and a record breaking heat wave coincided, causing mass die-offs of intertidal species due to temperature and increased rates of evaporation². 

Movement:  the mechanics of water in currents and wave action influence the habitability of in intertidal area.  While some organisms such as eel grass and sand dollars grow best in sheltered locations, other organisms such as Chiton and Green anemones thrive where wave action is the strongest³.  Water movement in the form of tidal fluctuation dramatically influences biodiversity. On some rocky coastlines, stratified layers of biological communities at different tidal levels can be easily visible, while in mudflats and tidal marshes, these layers may occur below the sand and out of site⁴.  Currents and wave action are also the primary source of life in the intertidal zone, refreshing the water with food, regulating temperature, and clearing away harmful contaminants.  

Figure 1: Example of a Temperate Rocky Shoreline Intertidal Zone

[1] Geng, Boufadel, and Jackson, “Evidence of Salt Accumulation in Beach Intertidal Zone Due to Evaporation.”

[2] Migdal, “More than a Billion Seashore Animals May Have Cooked to Death in B.C. Heat Wave…”

[3] DiNenno, “On the Edge.”

[4] “Biodiversity on Rocky Coasts.”

Intertidal zones house a variety of plant and animal species that are specifically suited to this somewhat inhospitable environment, which in turn act as food for both off-shore aquatic animals and on-shore mammals and birds: a critical nutrient pathway between the sea and the land that is exemplified by the impacts of intertidal herring spawning in the North Pacific and its impact on terrestrial ecosystems¹.  

The intertidal zone also serves as natural shoreline protection, regulating and shaping erosion, influencing saltwater incursion and inundation, and protecting low-lying areas from flooding in extreme weather events².

Beyond the above ecosystem services, intertidal zones are often the gateway for the general public to experience and interact with marine ecosystems in a positive and educational way. The multisensorial experience of exploring tidepools and wading at the waters edge cultivates wonder and appreciation for the richness that lies below the high-tide line.

[1] Walters, “Protecting (Marine) Subsidies.”

[2] “Intertidal Zone.”

Massive environmental change and degradation has been wrought in and around our coastal cities.  Intertidal ecosystems are constantly under threat from development of housing, infrastructure, and industry – Many of our coastal cities are built on artificial land extending beyond the historic shoreline.  Robbed of natural protection from waves and erosion, the new shoreline requires significant protective measures, further degrading habitat and costing significant sums in installation and maintenance.  The water in these intertidal zones is prone to contamination from run-off, sewage, and industry, causing heavy-metal buildup and algal blooms that ravage delicate ecological balance and dramatically reduce biodiversity.  Because the intertidal zone links terrestrial and aquatic ecosystems, the effects of this degradation extend far beyond the intertidal zone. Knowledge of this has prompted environmental designers to develop new ways of revitalizing and regenerating our urban intertidal zones across scales in ways that aim to integrate ecology and the resulting ecosystem services into our urban fabric.

Even non-urban coastlines are at risk from pollution, resource extraction, infrastructure, global warming and sea level rise (refer to Water Quality and Sea Level Rise for further information). Understanding the history of a coastline and any interventions that have occurred is critical at the outset of any project within the intertidal zone.

Figure 2 (left): ECOncrete’s tidepool creations at installation. Designboom.

Figure 3 (right): ECOncrete’s tidepool creations after colonization by intertidal species. ECOncrete.

With the ongoing and increasing threat of climate change impacts in the form of sea level rise and intense storm surges, intertidal zones are seen by many as the front-lines in a battle against nature. Environmental designers, equipped with an understanding of of the intertidal zone, are in a critical position to work with nature and the changing climate, rather than against it, in order to keep people and ecosystems safe. In parallel to the nature-based solutions to rainwater management presented in LID (see the Rainwater Management blog page), nature based solutions to urban intertidal conditions is a way forward that shows great promise. This can manifest in engineered solutions such as ECOncrete’s shoreline protection products that provide habitat for intertidal life1, as naturalized shoreline interventions such as Mithun’s Sea2City competition entry in False Creek, Vancouver, or as combined naturalized and engineered projects such as SCAPE’s well-known “Oystertexture” proposal for New York City3. Along with the environmental designer(s)’s extensive site-specific research, Interventions within the intertidal zone should involve ecologists, biologists and geotechnical engineers that are experts in local intertidal zone specifics: what may work in one location may be harmful in another.

DiNenno, Natalie. “On the Edge: The Curious Lives of Intertidal Organisms and How We Monitor Them.” U.S. National Park Service, 2022. https://www.nps.gov/articles/000/on-the-edge-the-curious-lives-of-intertidal-organisms-and-how-we-monitor-them.htm.

ECOncrete. “Shoreline Protection.” https://econcretetech.com/applications/shoreline-protection/.

Encyclopedia of the Environment. “Biodiversity on Rocky Coasts: Zoning and Ecological Relationships,” May 29, 2017. https://www.encyclopedie-environnement.org/en/life/biodiversity-on-rocky-coasts-zoning-and-ecological-relationships/.

Geng, Xiaolong, Michel C. Boufadel, and Nancy L. Jackson. “Evidence of Salt Accumulation in Beach Intertidal Zone Due to Evaporation.” Scientific Reports 6 (August 11, 2016): 31486. https://doi.org/10.1038/srep31486.

Migdal, Alex “More than a Billion Seashore Animals May Have Cooked to Death in B.C. Heat Wave, Says UBC Researcher | CBC News.” CBC, July 5, 2021. https://www.cbc.ca/news/canada/british-columbia/intertidal-animals-ubc-research-1.6090774.

Mithun. “Sea2City Design Challenge.” https://mithun.com/project/sea2city-design-challenge/.

National Geographic Education. “Intertidal Zone.” https://education.nationalgeographic.org/resource/intertidal-zone.

SCAPE. “Oyster-Tecture.” https://www.scapestudio.com/projects/oyster-tecture/.

Walters, Kristen. “Protecting (Marine) Subsidies: Nutrient Flows from Ocean to Land.” Raincoast Conservation Foundation, May 29, 2018. https://www.raincoast.org/2018/05/protecting-marine-subsidies-nutrient-flows-from-ocean-to-land/.

Images

Figure 1: Author’s work

Figure 2: Designboom, Lea Zeitoun. “ECOncrete® Blocks Are Bio-Enhanced Materials for Sustainable Marine Construction.” designboom | architecture & design magazine, February 9, 2022. https://www.designboom.com/technology/econcrete-coastalock-bio-enhanced-material-marine-construction-02-09-2022/.

Figure 3: ECOncrete. “Our Technology.” https://econcretetech.com/econcrete-technology/.

“Explore the Rocky Shore and Stanley Park.” Vancouver Natural History Society, 2009. https://naturevancouver.ca/wp-content/uploads/2018/12/Nature_Vancouver_Intertidal_Pamphlet.pdf.

Field guides and similar documents can be very helpful when designing for specific organisms and communities of organisms in the intertidal zone, as they often include information on habitat and relationships between species. This example is focused on the rocky shore of Stanley Park, Vancouver.

Thom, Ronald M., Heida L. Diefenderfer, John Vavrinec, and Amy B. Borde. “Restoring Resiliency: Case Studies from Pacific Northwest Estuarine Eelgrass (Zostera Marina L.) Ecosystems.” Estuaries and Coasts 35, no. 1 (January 1, 2012): 78–91. https://doi.org/10.1007/s12237-011-9430-6.

Eelgrass meadows are an important intertidal and subtidal ecosystem not covered significantly in this blog post. This research article is a helpful resource for those specifically interested in this.

Valiela, Ivan, Marci L. Cole, James Mcclelland, Jennifer Hauxwell, Just Cebrian, and Samantha B. Joye. “Role of Salt Marshes as Part of Coastal Landscapes.” In Concepts and Controversies in Tidal Marsh Ecology, edited by Michael P. Weinstein and Daniel A. Kreeger, 23–36. Dordrecht: Springer Netherlands, 2000. https://doi.org/10.1007/0-306-47534-0_3.

Access this article for further information on salt marshes, a critical intertidal ecosystem.

Raffaelli, David, and Stephen Hawkins. Intertidal Ecology. Springer Science & Business Media, 1996. https://link.springer.com/book/10.1007/978-94-009-1489-6.

This book is a helpful overview resource on intertidal ecology.

In the face of sea level rise and other climate change impacts, Oyster-tecture imagines working with the constructive nature of oysters to calm wave action, shelter shorelines, and clean contaminated water.

This project can be viewed here, or listen to 99% Invisible’s podcast on the project here.

New Brighton Salt Marsh: Connect Landscape Architecture
Vancouver, BC, Canada

An integration of a restored tidal salt marsh with public park and swimming pool in a complex urban/industrial area of Vancouver.

This project can be viewed here.

Lakes are formed by the filling of geological depressions or the containment of water by dams. Characteristics such as the depth, shape, and shoreline of lakes help to determine the hydrology and biology of their respective ecosystems.¹  They are important ecosystems as they provide many services including the provision of drinking water, irrigation supply, flood control, hydropower, transportation, biodiversity conservation, recreation, and aesthetics.² Marshes, however, go through cycles of flooding and drying, and inland marshes specifically can be characterized by their emergent vegetation, grasses, rushes, and sedges.³ Further information about marshes can be found under wetlands.

[1] Suring, “Lentic Freshwater.”

[2] Jørgensen, “Freshwater Lakes.”

[3] Craft, “Inland Marshes.”

Lakes and ponds

Anthropogenic activity around lakes causes various concerns, particularly surrounding water quality. Eutrophication is a primary concern of lake health as wastewater, industrial or agricultural drainage, and/or runoff causes the inflow of excess nutrients into lakes, ultimately damaging the lake’s ecosystem through the impact on oxygen levels and subsequently the aquatic species affected by the chemical change. Runoff and wastewater also have the potential to transfer pathogens into the lakes, thus impacting the safe consumption of lake water. Another impact on lakes is large changes in water levels caused by the diversion of incoming water or by the removal or use of large quantities of water from these waterbodies. Changes in water level have the potential to trigger other processes such as eutrophication or salinization, or impact the ecosystem in other ways, for instance, through the reduction of fish spawning habitat caused by siltation.¹ Additional impacts include fishing, noise and light pollution, and the introduction of invasive species.² Ultimately, it’s important to understand that activities associated with lakes and ponds, and those upland of these waterbodies, will have an impact on the water quality and therefore need to be properly managed to minimize disruptions to these ecosystems.

[1] Jørgensen, “Freshwater Lakes.”

[2] Strecker, McGrew, and Chiapella, “Lake and Pond Ecosystems.”

In lakes and reservoirs where the water has been negatively impacted, restoration processes can be implemented to help bring back the natural potential of the waterbody. The primary methods of lake restoration include the removal of contaminants, the reduction/prevention of agricultural runoff and wastewater from entering to prevent processes such as eutrophication, and the overall improvement of water quality and aquatic ecosystems. Methods of lake restoration should be carried out at a watershed scale as water is interconnected in its different forms throughout the water cycle.¹

[1] Dhir, “Wetland, Watershed, and Lake Restoration.”

Craft, Christopher. “Inland Marshes.” In Creating and Restoring Wetlands, 117–61. Elsevier, 2022. https://doi.org/10.1016/B978-0-12-823981-0.00014-9.

Dhir, Bhupinder. “Wetland, Watershed, and Lake Restoration.” In Handbook of Ecological and Ecosystem Engineering, edited by Majeti Narasimha Vara Prasad, 1st ed., 247–59. Wiley, 2021. https://doi.org/10.1002/9781119678595.ch13.

Jørgensen, Sven E. “Freshwater Lakes.” In Encyclopedia of Ecology, 509–13. Elsevier, 2008. https://doi.org/10.1016/B978-0-444-63768-0.00339-5.

Marsh, G. Alex, and Rhodes W. Fairbridge. “Lentic and Lotic Ecosystems.” In Environmental Geology, 381–88. Encyclopedia of Earth Science. Dordrecht: Kluwer Academic Publishers, 1999. https://doi.org/10.1007/1-4020-4494-1_204.

Strecker, Angela L., Alicia McGrew, and Ariana Chiapella. “Lake and Pond Ecosystems.” In Reference Module in Life Sciences, B9780128225622000700. Elsevier, 2022. https://doi.org/10.1016/B978-0-12-822562-2.00070-0.

Suring, Lowell H. “Lentic Freshwater: Lakes.” In Encyclopedia of the World’s Biomes, 121–30. Elsevier, 2020. https://doi.org/10.1016/B978-0-12-409548-9.12074-3.

“Identified as the first phase of development of Jurong Lake Gardens, Singapore’s third national garden and the first in the heartlands, Lakeside Garden is a 53-hecare site that looks to restore the landscape heritage of the freshwater swamp forest as a canvas for recreation and community activities. The development is envisioned to be a “people’s garden” accessible to all segments of the community and is a conscious effort to bring back the nature that was once unique to the area.”

This project can be accessed on Landezine and the firm’s website.

Rivers then and today have many functions, including the generation of electricity, the supply of water, transportation, the harvesting and cultivation of fish, recreational uses, and the transportation of sediment.^1,2

Streams and rivers are formed as rainfall travels as surface runoff into the channels of streams and rivers or through groundwater stores in which groundwater emerges from springs onto the surface. As water emerges from groundwater springs and merges into other streams, the width of the channel and the water flow generally increases, and as it increases in size, the stream may be identified as a river.³ (As noted by Hildrew and Giller, “There is really no formal definition of this change, and terminology is largely a point of view and culturally determined”).⁴

[1] Dhir, “Wetland, Watershed, and Lake Restoration.”

[2] Marsh and Fairbridge, “Lentic and Lotic Ecosystems.”

[3] Hildrew and Giller, The Biology and Ecology of Streams and Rivers.

[4] Hildrew and Giller.

The various factors affecting the natural functioning of rivers include water pollution, the extraction and increased demand of water, the manipulation of stream channels, the use of water for hydropower, expansion of agriculture, overfishing, introduction of alien species, and artificial light and noise, which disrupt the normal behaviour of aquatic species. Additionally, climate change, especially its associated increased temperatures, is threatening freshwater ecosystems through diminished areas of these waterbodies, altered precipitation patterns, and more frequent flooding and drought events.¹

Water pollution comes from various agricultural and industrial sources, and incorporates many contaminants, which range from pesticides to plastic particles and endocrine disruptors. Additionally, agriculture contributes to increased sedimentation as soil erosion washes sediments into nearby streams.²

In urban regions, the area of impervious surfaces is much greater, leading to decreased infiltration and increased amounts of runoff that makes its way into streams. Urban streams therefore have more frequent flooding events than forested streams. They also typically have higher concentrations of chemicals that are received from wastewater, storms sewers, and runoff. Additionally, since many cities have combined sewer and stormwater pipes, rainstorms will contribute to sewer overflows, resulting in effluents released into urban streams.³

[1] Hildrew and Giller.

[2] Hildrew and Giller.

[3] Meyer, “Urban Aquatic Ecosystems.”

With the factors influencing lotic ecosystems, restoration is an important consideration for streams and rivers. Streams are often impacted by the modification of its channels, and restoration therefore involves the reversal of these changes, such as the widening of the stream’s channels and the regrowth of its riparian vegetation.¹ The restoration of streams and rivers is often much more intricate though, and includes not only structural modifications, but also physical, chemical, and biological methods to alter water flow and restore plants and aquatic species. Restoration of rivers and streams aims to promote channel-floodplain connectivity and restore the natural water and sediment dynamics, which can be done in a multitude of different ways. These methods, however, involve many different stakeholders and a comprehensive understanding of the respective watershed.²

[1] Dhir, “Wetland, Watershed, and Lake Restoration.”

[2] Dhir.

Dhir, Bhupinder. “Wetland, Watershed, and Lake Restoration.” In Handbook of Ecological and Ecosystem Engineering, edited by Majeti Narasimha Vara Prasad, 1st ed., 247–59. Wiley, 2021. https://doi.org/10.1002/9781119678595.ch13.

Hildrew, Alan, and Paul Giller. The Biology and Ecology of Streams and Rivers. 2nd ed. Oxford University PressOxford, 2023. https://doi.org/10.1093/oso/9780198516101.001.0001.

Marsh, G. Alex, and Rhodes W. Fairbridge. “Lentic and Lotic Ecosystems.” In Environmental Geology, 381–88. Encyclopedia of Earth Science. Dordrecht: Kluwer Academic Publishers, 1999. https://doi.org/10.1007/1-4020-4494-1_204. Meyer, J.L. “Urban Aquatic Ecosystems.” In Encyclopedia of Inland Waters, 367–77. Elsevier, 2009. https://doi.org/10.1016/B978-012370626-3.00236-2.

Glaciers have a variety of important functions, including:

The storage and provision of water. Glaciers store water and feed rivers and groundwater that is then used for human and industrial use.

The survival of their respective native vegetation. The melting of glaciers provides water for vegetation near glaciated areas, especially in elevated environments where water is scarce.

Aesthetics and recreation. Glaciers contribute to a variety of outdoor recreational activities such as mountaineering, hiking, or skiing.

They provide a glimpse into history. As glaciers are formed by layers of ice layering year by year, the sampling of ice provides insight into atmosphere conditions of the past¹.

[1] Taillant.

Ice sheets. These are large masses of glacial ice that are also referred to as continental glaciers. There are two major ice sheets that currently exist, one in Greenland and one in Antarctica, each covering tens of thousands of square kilometers of land¹.

Ice shelves. These are floating ice sheets that extend from land masses. They create a barrier around land that slows the migration of ice sheets into the ocean and may contribute to the slowing of sea level rise due to this function².

Icebergs. These are not a type of glacier, but rather pieces of a glacier that are broken off ice shelves in a range of sizes. They provide nutrients as they melt that act to nourish plankton, fish, and other aquatic life³.

Additionally, while not a glacier itself, there is another region with large amounts of stored ice called the periglacial environment. These environments store these quantities of ice below the surface of the earth. During the winter, the periglacial environment freezes, capturing humidity underneath and storing it as ice. It subsequently warms and melts in the summer, releasing water to the lower ecosystem. Some portions called permafrost, however, are continuously frozen, or frozen for a large percentage of the time. A characteristic of the periglacial environment is a lack of vegetation, as plants have difficulty surviving in the thaw-freeze cycles. These environments will survive beyond the melting of glaciers, and therefore may play an important role in water provision⁴.

[1] Knight, Glaciers.

[2] “Glaciers, Ice Sheets, and More: A Primer on the Different Types of Polar Ice.”

[3] “Glaciers, Ice Sheets, and More: A Primer on the Different Types of Polar Ice.”

[4] Taillant, Glaciers: The Politics of Ice.

Due to rising temperatures, spurred by climate change, glaciers are shrinking and being pushed up vertically as they move to cooler environments. As the climate becomes too warm, glaciers will melt altogether, and will no longer serve their important role of storing and releasing water back into the environment¹.

Other anthropogenic activities have an impact on glaciers, with increased industrial activity near glaciers being one of them, as they alter the microclimates around glaciers. The dust and particles from industry can also contaminate glaciers and provoke glacial melt. The activities of industry emit carbon as well, interfering and darkening the surface, triggering temperature changes².

[1] Taillant.

[2] Taillant.

As glaciers melt, chunks of ice may fall into lakes and valleys below. They can also dam lakes, which, when melted, will release large amounts of water rapidly into downstream areas and tributaries¹.

The vanishing of glaciers will cause environments that were once protected by ice to be susceptible to erosion which will impact biodiversity within these regions. There will also be a strain on hydroelectric power supplies, agricultural water supplies, and of course, drinking water. If glaciers melt altogether, snow melt will be the primary provider for rivers, but will ultimately be seasonal as it too will melt in warmer weather, creating prolonged dry periods throughout the year. Rivers will be seasonal and basins that rely on glaciers for their water supply will go dry, prompting water shortages for hundreds of millions of people².

[1] Taillant.

[2] Taillant.

“Glaciers, Ice Sheets, and More: A Primer on the Different Types of Polar Ice.” https://news.climate.columbia.edu/2018/02/05/glaciers-ice-sheets-polar-ice/.

Knight, Peter G. Glaciers. Stanley Thornes, 1999. https://read.kortext.com/reader/pdf/494836/4.

Taillant, Jorge Daniel. Glaciers: The Politics of Ice. Oxford University Press, 2015. https://ebookcentral.proquest.com/lib/ubc/reader.action?docID=2033574.

Glaciers: The Politics of Ice by Jorge Daniel Taillant

This book provides an understanding of glaciers, their role in the environment, and the various types of glaciers and ice. It also introduces the periglacial environment and the importance of this ecosystem. Going beyond this, it addresses how climate change currently is- and will continue to- melt glaciers and what the subsequent impacts of receding glaciers are. There is, however, hope offered through the story of the enactment of a glacial protection law, as well as examples of how individuals are working to preserve or create glaciers, which may be accessed within Chapter 8 “Amazing Glacier Stuff”.

“The natural landscape was the inspiration for the design and also informed the materiality. The thrust-fault geological movement in the area has created a fractal landscape, influencing the architectural form. The angular forms, rusted hues, and warm texture of the Corten steel finish relate to the rocky outcroppings of the surrounding mountains. The glazing mimics the glacial flow below.”

This project can be viewed on the firm’s website and on ArchDaily.

“This thesis explores and demonstrates that landscape architecture, a field that is, until now, uninvolved in retreating glacial landscapes, has the capacity to address the psychological experience of glacier retreat in order to foster engagement with environmental degradation.”

This thesis can be viewed here.

The flow of water through the watershed is dictated by many characteristics, including the shape of the watershed, the topography, the geology, the soil composition, and land use and cover. Due to these variables, the composition of watersheds will vary, but includes streams, tributaries, groundwater, a receiving waterbody or basin outlet, and often sub-basins.¹

Water is inputted into the watershed through precipitation or snowmelt, and then subsequently stored, converted into other forms, or diverted via runoff and streamflow. When water is stored, it occurs through water uptake by plants, through storage at the surface of soil, and via groundwater recharge. Water uptake occurs in varying capacities according to the amount or type of vegetative cover. A portion of the water uptake is later released into the water cycle through evaporation, transpiration, or evapotranspiration.²

[1] Letsinger et al., “Geohydrology.”

[2] Letsinger et al.

The urban environment has a tremendous impact on the functioning of watersheds, with the following stresses being induced:

• The loss of natural habitat, thus threatening biodiversity
• Heat islands
• The alteration of hydrological and biogeochemical cycles
• The introduction of pollutants into ground and surface water¹
• Increased vulnerability in the event of natural disasters such as storms, floods, droughts, and landslides²

[1] Huang et al., “Patterns and Distributions of Urban Expansion in Global Watersheds.”

[2] Huang et al., “Patterns and Distributions of Urban Expansion in Global Watersheds.”

The management of a watershed requires a multi-disciplinary approach, and because of this, it’s important as a designer to be aware of the broader system (watershed) that designs are situated within, as well as the impacts facing each respective watershed as each are unique in their composition. The link HERE provides the delineations of the watersheds within Canada at various scales.

As the impacts on watersheds are often experienced during pronounced climatic events, it is important to consider how designs will respond to such events, as the timing and intensity of these weather patterns themselves cannot be controlled. During periods of precipitation, for example, water can be taken up by plants, recharge groundwater, accumulate in areas where the water table is already high and the soil is saturated, or contribute to runoff.¹ As such, below are a few important considerations:

• The placement of vegetation. Increased infiltration of water (through methods such as planting) helps reduce runoff, mitigate flooding, and increases the groundwater levels to reduce drought during periods of low precipitation. This is critical in areas of steep terrain as fast-moving water and instable slopes create the risk of landslides (insert hyperlink to landslide blog here). It is also critical along riparian buffers that intercept the runoff that will flow into aquatic systems².
• Land use considerations. This includes both the topography (steepness of terrain in particular) and the varying land types that comprise watersheds. Some of the land types included in this assessment are agricultural land, forest land, urban areas, riparian zones, and waterbodies. The various land types are unique in their composition, yet all impact the health of the watershed and should therefore be considered holistically when undergoing watershed management. For example, agricultural lands are often high in water consumption and contribute pollutants into the watershed through their fertilization requirements. Interventions in agricultural lands may include vegetated filter strips to slow runoff and the movement of pollutants, as well as cover crops to improve soil health. They should be appropriately placed in consideration of the adjacent land type within the watershed³.
• Impermeable surfaces and the use of blue-green infrastructure. Urban development increases the amount and area of impermeable surfaces. This then diverts and increases runoff as water is unable to permeate through soil. Soil compaction is also increased, which similarly reduces infiltration and thus increases runoff. To mitigate these effects, designs can incorporate architectural solutions such as permeable surfaces and blue-green infrastructure⁴.

[1] Tomer, “Watershed Management.”

[2] Letsinger et al., “Geohydrology.”

[3] Tomer, “Watershed Management.”

[4] Tomer.

Huang, Qingxu, Han Zhang, Jasper Van Vliet, Qiang Ren, Raymond Yu Wang, Shiqiang Du, Zhifeng Liu, and Chunyang He. “Patterns and Distributions of Urban Expansion in Global Watersheds.” Earth’s Future 9, no. 8 (August 2021): e2021EF002062. https://doi.org/10.1029/2021EF002062.

Letsinger, Sally L., Allison Balberg, Elias Hanna, and Erin K. Hiatt. “Geohydrology: Watershed Hydrology.” In Encyclopedia of Geology, 442–56. Elsevier, 2021. https://doi.org/10.1016/B978-0-12-409548-9.12389-9.

Tomer, M.D. “Watershed Management.” In Reference Module in Earth Systems and Environmental Sciences, B978012409548909117X. Elsevier, 2014. https://doi.org/10.1016/B978-0-12-409548-9.09117-X.

Watershed Characterization: City of Vancouver

This document that provides an overview of the City of Vancouver’s urban watersheds as well as insight into the various factors affecting their health and management.

Watershed Management by M.D. Tomer

This article provides an overview of the factors affecting watershed health, with an emphasis on how the role of water quality and land use contribute to and are affected by climatic events. In summarizing the complexity of issues facing watersheds, as well as the importance of considering local conditions, it provides an insight into watershed assessment and a brief methodology for how watershed management may be approached.

“EPA addresses water pollution from the watershed approach, a comprehensive framework for addressing water resource challenges….Restoring water quality is most effective when pollution sources, stressors and solutions are identified for the entire watershed.”