Healing Rivers through Ecological Design
By Lauren Valle
For centuries, rivers around the world have been managed and exploited to meet human needs. We dam rivers to create hydroelectric power, we dump industrial toxins into rivers, rivers absorb runoff from agricultural waste, we cut off and divert the flow of rivers so that we can build roads and buildings, we line the banks of rivers with concrete to control erosion and so that we can dock ships and have riverside boardwalks.
Since the passing of the Clean Water Act in 1972 many of the rivers in the United States have been cleaned up and restored to health so that they are safe for recreational use. This is not the case for many rivers in developing countries where rivers are still highly polluted with excess nutrients and bacteria from human and animal waste and industrial contaminants.
Even protected rivers in the Unites States are still compromised by storm water runoff containing pollution from our towns and cities as well as excess nutrients from agriculture fertilizers and discharge from wastewater treatment plants. Many rivers around the world experience a process called “eutrophication”, where excess nutrients from runoff cause a dense growth of algae and plant life which ultimately depletes the oxygen from the water and makes the river uninhabitable to many species. Eutrophication is the main force behind the decline in health and vital forces of a river.
The fate of our rivers around the globe today is hugely influenced by the field of civil and environmental engineering. Engineers, along with municipal officials, architects and landscape architects, are responsible for designing the human world we live in, from the buildings we inhabit to parks, bridges, highways and neighborhoods. Conventional engineering is focused on human-centric design motives: how can infrastructure be designed, and land and waters be manipulated, to best serve the human population and our commercial, industrial and recreational activities?
Emerging design thinking based on nature’s intelligence
In the past 40 years the field of ecological design, also called ecological engineering, has emerged to bridge the gap between the built world and the natural world and design the human world based on the intelligence of nature.
The field of ecology focuses on the relationship between living organisms and their environments. Ecology seeks to understand the functioning of an ecosystem and the complex relationship between living organisms in a particular place. Humans are organisms within an ecosystem.
The Journal of Ecological Engineering tells us that, "the field of ecological design, or ecological engineering, is a response to the growing need for engineering practice to provide for human welfare while at the same time protecting the natural environment from which goods and services are drawn. It recognizes that humanity is inseparable from and dependent on natural systems, and that the growing worldwide population and consumption have damaged, and will increasingly stress, global ecosystems. Ecological engineering is the design of sustainable systems, consistent with ecological principles, which integrate human society with its natural environment for the benefit of both. It recognizes the relationship of organisms (including humans) with their environment and the constraints on design imposed by the complexity, variability and uncertainty inherent to natural systems". 1
Ecological designers study the natural intelligence of the ecosystem to create self-sustaining, regenerating landscapes where an abundance of organisms up and down the food chain can thrive alongside humans. Another term for this type of design thinking is called Biomimicry.
The health of an ecosystem can be measured by system vigor, organization and resilience to stress as well as levels of biodiversity. This amounts to increasing the vital force of the river so that the river can enact its own dynamic forces of change, succession, cleansing and remediation.
When it comes to working with rivers, ecological designers endeavor to come up with solutions that both restore the biological integrity of the river, giving the river tools to heal itself from eutrophication and other stressors, while maintaining, or improving, the function and use of the river for humans. Ecological designers take into consideration the entirety of the river’s ecosystem and its origins and life-cycles, from the riparian habitats along its banks to the wetlands, headwaters, delta and floodplains, in determining a best design or intervention for a river.
River-based ecological design in action
The diagram below from BioHabitats illustrates that when we follow nature’s example and create a meandering flow of water instead of a straight line we are increasing the diversity of water conditions within the river. We can create pockets of swift moving and slow-moving water as well as deeper and shallower areas so that different life forms, requiring different conditions, can proliferate and the river can support more diversity, and thus, gain greater health.
Many fascinating projects involving rivers have been built or are currently in the works as an ecological design approach gains traction as an answer to the growing impacts on our current infrastructure of climate change and rising water levels, resource depletion and over-population. Towns and cities around the world are recognizing that the future of human infrastructure must account for the health and restoration of our natural environments or we will not have a place to live.
One example of an ecological design strategy that is commonly used in rivers is artificial wetlands. Wetlands play an essential role in healthy river ecosystems, allowing rivers to recycle and sequester nutrients such as nitrogen and phosphorus as well as serving as a nursery and habitat for many river species. Yet more than 50% of the world’s wetlands have been bulldozed over or filled in to make room for human development. Reintroducing wetlands to rivers restores the river to health as well as providing beauty and interaction for humans.
The “River Restorer”
Dr. John Todd, an early pioneer in the field of ecological design, undertook a project in the early 1990’s to install artificial wetlands with a boardwalk along the Baima Canal in Fuzou, China. He called this design the “River Restorer”. The Baima Canal, running through the heart of this mid-sized city, was nearly dead from heavy pollution. The pictures below tell the story: the canal was transformed from a toxic, smelly dump to a beautiful water-park that became an amenity and connection to nature for the citizens of Fuzou.
How to bring about an era of ecological infrastructure for all our communities?
If we are to truly reconnect with our rivers, these magnificent currents of life that run through our towns and cities, we must advocate for their ecological health. As citizens, how can we do this? We can educate ourselves about the current health status of our local rivers. We can get together with others in our community to imagine how our local rivers can be rewoven back in the everyday lives of our communities: what would it be like to walk along the banks of our local rivers, to smell a healthy river, to witness flocks of birds, flowering plants, baby turtles sunning along the banks, children playing in their shallow waters? Then we can campaign for the adoption of these projects to our local decision makers. We can show up at planning meetings, put together presentations, give examples of other projects, and shepherd this new era of ecological infrastructure into existence in our communities. If we don’t do it, will the next generation have the opportunity or will it be too late?
Regenerative Design Group
1. Design Principles for ecological engineering
Scott D Bergen. SusanM Bolton, James T. Fridley
Ecological Engineering. Volume 18 Issue 2, December 2001 pp. 201-21