“The evaporation to precipitation ratio in our bioregion is 1:1. That means, all rain that falls evaporates back into the air,” said Jim Patchett of Conservation Design Forum. Stunned, I asked the obvious next question, How in the world was our region in northern Illinois so rich in groundwater supplies? What, does it just pull it out of thin air? Well, actually, yes.
In prairies, life holds onto water as long as possible because without doing so summer heat and drought would result in death. As Jim explained, turns out prairie ecosystems solved for this problem in a few different ways. First, prairie plants hold on to stormwater – the runoff from a prairie ecosystem is extremely low, in some places virtually non-existent. And two other processes are occurring – condensation in which water close to the ground falls onto plant and soil surfaces where it can be absorbed, and the capture and reabsorption of water released during the respiration (breathing) of plant roots. Over time, the collection and subsequent channeling of water deep underground creates a net positive balance of water in the ecosystem, resulting in a reservoir plants can tap into during times of drought.
As I mentioned in my last post, people working on drinking water supplies in the Chicago region know that the numbers that play out into the future are dire – there is simply not enough groundwater (in addition to our federally-limited allotment of Lake Michigan water) to support a growing urban and suburban population, and pollution is increasingly concentrated in the existing groundwater supplies. On the flip side, stormwater experts are grappling with the increasing intensity of stormwater events, resulting often in a failure of stormwater infrastructure systems to accommodate the increased flow. These systems were designed and built to capture and shed an amount of water based on the historical intensity of rain events and assumptions (which were underestimated) about the growing percentage of impermeable surfaces – and of course not based on predicted future storm intensity trends influenced by climate change.
Putting these two challenges in one paragraph makes you wonder – if we have so much rain that we can’t shed it fast enough, yet our water supply is dwindling….why are we sending our water to the Gulf of Mexico? Add to that the ratio of 1:1 of evaporation and precipitation in native ecosystems (and I’m curious if that ratio changes with an increase in impermeable surfaces, turf grass and agriculture), and it’s clear it’s not just a matter of over-consumption and leaks. It’s a complete failure to understand and then take into account the limitations and functioning of our local water cycles in the design of human water management systems. Our regional water systems therefore fail to ensure sustainability and resiliency of both human and non-human systems in the long run.
Our Shared Story of Ecosystem Disruption
Some version of this story is happening everywhere. As we change the landscape with our modern built environment, we continue to disrupt systems and push the boundaries ecosystems manage to survive within. In some cases, those cycles are now simply broken and the repercussions are slowly (and sometimes not so slowly) unfolding. And while advocates riding the resiliency wave – and sometimes eschewing the sustainability wave – might point out that nature is constantly adapting to changing conditions (what we refer to as dynamic nonequilibrium), so as long as we have resilient strategies in place we’ll figure it out too. Nothing ever stays the same and complex adaptive systems are masters at absorbing impacts and coming back perhaps slightly different, but just as resilient over time. What is there to “sustain” if nothing lasts forever? So things will change but we’ll be ready. Mother Nature give us your best shot! We can learn to adapt, right?
The answer to that in my mind is a big fat Maybe. While certainly our human systems can learn significant lessons from ecosystem resilience, all of this resides within a larger context, which is defined by the limits and boundaries of the system. Our Earth has not always been this way – life has slowly over time and helped to create the planetary conditions we know and love (and need for our survival) today. Systems at all levels have evolved over time to be both sustainable and resilient within the limitations presented by their relevant operating conditions. What we do know is that if an ecosystem is thrown way out of balance (which may be a cumulative result of small events over decades (short in geologic time), or a sudden major disturbance), the system – at the local, regional or planetary scale – can suddenly shift into another state altogether (called an alternative stable state) and won’t go back.
And while it could be that we will learn to adapt to this new alternative state of the natural world, it could also be that we will not be able to adapt fast enough. We simply don’t know what that new alternate state might be. Either way it will have (and is currently having) enormous impacts on all of humanity. And we are doing it to ourselves! It’s not like we are helpless in the face of a fickle and retributive Mother Nature – we are doing this to the planet, and therefore to ourselves. Which means, of course, that it’s possible to change our actions to achieve a different outcome.
A Regenerative Mindset and Approach
I love this quote from the book Designing for Hope (2015) by Dominique Hes and Chrisna du Plessis in reference to a new interpretation of sustainability, the “ecological worldview”:
So how do we change the way we design so that we improve ecological sustainability first and foremost in a way that also strengthens (while perhaps shifting) our social and economic systems at the same time? The regenerative design examples included in Designing for Hope offer incredible insight into how a mental shift – designing from a place of understanding that humans are a part of, not separate from, other life systems – can change everything. It allows us to see that our built environment has the potential to participate – support and give back – to the life systems that support us (also check out Janis Birkeland’s Positive Development: From Virtuous Cycles to Virtuous Cycles through Built Environment Design (2008)).
It also then enables us to go beyond our current boxed-in thinking about our built environment. With respect to Chicago’s water challenges, the water conversation on the supply side focuses on plugging leaks and reducing consumption (based on the mindset of “doing less bad”), while the stormwater questions focus on increasing green infrastructure and detaining water in place and releasing it slowly enough that wastewater plants aren’t overwhelmed.
But if we take into account our understanding of how a prairie was net positive for water (right here under the same conditions), something we are not even close to achieving with our city water systems, we realize the next obvious questions we urgently need to ask are – How can we first hold onto rainwater as long as possible and not let it escape the region to level that ratio of 1:1 so we aren’t operating at a deficit? And since we aren’t going to bulldoze Chicago to restore a prairie, how can we replicate the prairie ecosystem processes of condensation and capture of respiration in our built environment so we come out ahead? And how do we know when we are actually “sustainable” with respect to our local ecosystem?
Using Biomimicry to Evaluate Success of a Regenerative Built Environment
That last question might be hardest to answer. However using the biomimicry methodology we can begin to collect information from biological research on the numbers associated with how water is managed in a prairie ecosystem to create system-wide design goals. For example, if basically all stormwater that falls on a prairie is captured and held within the ecosystem, this gives us a baseline from which to measure our stormwater systems and evaluate if they are contributing positively or negatively to the successful functioning of water cycles within our ecosystem. Gathering many of these metrics (e.g., for evaporation, condensation, capture of water from respiration, groundwater recharge rates, etc.) can help us start to reevaluate our water systems as a whole. We can then begin to rethink and redesign our water systems to reflect our understanding of the limitations presented by our local operating conditions and knowledge gained from solutions embodied in native ecosystems.
Janine Benyus describes these metrics as “ecological performance standards” (EPS). One benefit I see with EPS is that they deliver goals which designers, architects, planners and engineers can try to meet with existing off-the-shelf technology (before more advanced innovations slowly make their way into the market). Of course, the risk might be that we design only for one metric without understanding the need for a holistic design that gets as close as possible to every metric that represents successful functioning of the system as a whole. And certainly an iterative process that allows our built environment to adapt and respond to the system as it is restored (or perhaps disrupted) will enable us to incorporate new technology and approaches as our understanding and capabilities evolve. Existing efforts to use EPS to address water challenges such as the Seattle Urban Greenprint project, Biomimicry South Africa’s Genius of Space and Durban Urban Resilience Framework projects, Terrapin Bright Green’s project in Buffalo, New York, and Biomimicry 3.8’s current project with Interface all aim to establish what it means and how to apply EPS on a city scale or project site. We are aiming to start a similar effort in Chicago.
We can of course also use the biomimicry methodology to solve for challenges that current design approaches and technology don’t address (or don’t do very well). Within every ecosystem there are plentiful examples of how organisms deal with the same operating conditions – and therefore challenges – that we are trying to solve for. Each of those species presents an opportunity for us to learn a new design principle upon which we might base a new innovative design. This process of looking at local organisms, including the deep patterns we find among them, to solve local built environment problems enables our built environment to be more attuned to place, and thus more likely to be able to sustainably function long term as well as respond to disturbances. In biomimicry we call this “Genius of Place”.
We must take the next step in our built environment design to think about the larger ecological, social and economic systems within which our designs reside. This step must be based on an underpinning of acknowledgement that not only is our success dependent upon the success of thriving ecosystems, but also that we have a direct and crucial role to play in contributing to the functioning of the system and the creation of opportunities for life to thrive. Therefore, it’s not enough to “do less bad” when it comes to our built environment. We need to actively restore and regenerate the functionality and resilience of local ecosystems to try to mitigate the radical shifts of larger planetary systems in motion, while at the same time shore up the resilience of human systems. Because change is coming to both.
- How do your local city water systems either work with or against your local water cycles?
- What can you learn from your local ecosystem and species about how to effectively manage water on site in a way that benefits both human and non-human communities?
- What system metrics can your community strive to meet?