Freshwater is perhaps the most vital resource for the 21st century — necessary for almost all aspects of growing economies, traditional livelihoods, and vibrant terrestrial and aquatic ecosystems. But freshwater resources are increasingly difficult to manage as our future becomes harder to predict with confidence: shifting demographics, new patters in climate variability, and rapidly evolving economies.
Many of the decisions we make around water have long-lasting impacts: our decisions are durable, and a bad decision can endure for a long time. New infrastructure, for instance, will last decades, even centuries. Do we know how to think about sustainable water management over those timescales?
This site is intended to showcase a new way for identifying future water risks and then addressing them. First we describe the approach — called decision scaling — which developed within recent years from the engineering community. Then we talk about how long-term sustainability has to include ecosystems within built infrastructure. That approach is called eco-engineering decision scaling, or EEDS.
This site was developed as a result of a Nature Climate Change paper prepared by both ecologists and engineers on EEDS in 2015. The NCC paper can be found on ResearchGate here.
An Introduction to Decision Scaling
A Crisis of Confidence in Managing Risk: Something Isn’t Working
Large water engineering projects have been a staple of modern engineering since the early nineteenth century. The development of water resources has been the pathway for developing modern economies — securing water for energy, food, cities, and security from floods and droughts. The most developed countries such as the United States have more than 75,000 dams, about 10 percent of the global total. Countries that are shifting from subsistence livelihoods to manufacturing and service economies are simultaneously changing how they manage their water resources — and often building or modifying new infrastructure. Developed economies often invest heavily in maintaining or modifying their extensive water infrastructure investments.
These pieces of infrastructure can last very long periods — very often decades, and sometimes centuries or even millennia in places such as China, India, Turkey, Peru, and Yemen. The longevity of most water infrastructure means that they are almost invariably exposed to changing environmental, demographic, and economic conditions. These are difficult for water managers, stakeholders, decision makers, and infrastructure designers and operators to predict and anticipate. Should we plan for a single future? Many futures? What factors are relevant? What may change over time?
In 2011, the International Joint Commission was in the middle of a five-year planning cycle for the International Upper Great Lakes Study (IUGLS), a team managing a large, diverse group of stakeholders sharing one of the world’s largest lakes divided between two countries. These stakeholders were confronted with an impasse: how do we plan for the future of Lake Superior given conflicting, divergent predictions of the future? How do we change uncertainty into confident decisions? In response, a new and untested methodology was proposed as a way to visualize risk. Climate information was considered critical to this process. In most cases, climate information is “downscaled” for decision makers. In this case, climate information was presented through a new methodology known as “decision scaling.”
What Does Decision Scaling Look Like?
The traditional starting place for water management decision making begins by defining a need (energy, clean water, flood control, reliable irrigation) and then asking what the future will look like — for that need, for the infrastructure designed to provide that need, and the conditions that might influence the need and the infrastructure over time. Until recently, most water infrastructure projects assumed that environmental factors did not evolve much — they were “stationary.” If decision makers had access to enough historic data, they could design and operate the infrastructure to encompass all of that data. That usefulness of that assumption is now widely questioned. To be sustainable and responsible, we need to design for longer timescales, especially as the environment changes.
Climate models — often called GCMs or global circulation models — are often a critical tool in estimating environmental change. They help inform decisions about how the amount of water and variability will change over the long lifetime of infrastructure. Localizing global-scale climate models to the scale of a project or city has proven dissatisfying in many cases, and these models have been widely criticized as inappropriate for long-term sustainable resource management. Because climate models define the range of choices from the beginning for stakeholders, downscaling is often referred to as a top-down methodology.
Decision scaling is a way of looking at climatic and environmental data in the context of stakeholder-defined needs. Stakeholders define “breaking points” for their area of interest — crop yield, water delivery volumes, profit and loss, water quality. These breaking points are then used as the basis for a stress test, which explores the role of climatic change and variability for the qualities that are important to stakeholders. Climate models may be used, but they are often supplemented with many other sources of information. Because the process is stakeholder-driven (i.e., involving planners, engineers, conservation ecologists, economic investment institutions), it is known as a “bottom-up” approach. For each individual project, a different set of variables may be examined and evaluated against different definitions of success. As a result, a water management project should be both more successful in the eyes of stakeholders and more robust to an uncertain, complex future.
An Introduction to Eco-Engineering Decision Scaling (EEDS)
Integrating Ecosystems into Infrastructure:
Why Can’t Engineers and Ecologists Get Along?
Values and approaches to design and natural resource management change over time. In the same way that concerns about the assumption of stationarity created an opening for rethinking the role of climate, a desire to minimize negative ecological impacts from dams has grown since the 1960s worldwide. In practice, ecologists have often served as the scientific “voice” of aquatic ecosystems, opposing the work of engineers. In contrast, the task of economic development and poverty alleviation worldwide has often deeply involved the work of engineers designing water infrastructure. Both disciplines have honorable goals.
Over recent decades, these disciplines have found little common ground, however. Their differences have been exacerbated by significant differences in how they define sustainability. Indeed, they often use distinct words to describe how sustainability should function: ecosystems should be “resilient” to impacts and change, while infrastructure should be “robust” to a range of possible futures. In many cases, the qualities that ecologists used to define resilience could not be easily translated into the operational and design language of engineers. Certainly most engineers care deeply, even passionately, about sustainability and ecosystems. But the resilience-robustness gap has proven durable.
Given such a mixed history of collaboration and the difficulties in developing a common language and approach to sustainable water management, how can these disciplines overcome their differences? How can they span the water dividing them?
Crossing Over: Ecologists Learn to Speak Engineering
To most aquatic ecologists, engineers seem deeply powerful. Their discipline communicates easily with decision makers and translates into the language of economics and finance, while their influence over water infrastructure design and operations is profound. Ecologists have often felt as if they were on the outside of an important conversation, their own voices lost.
Ecosystems have most often been represented in water management decisions by describing the water variables that are believed to be important for particular species or groups of species. Beginning in the 1990s, a more sophisticated approach looked at whole ecosystems by focusing on the “natural flow regime” — managing water infrastructure to mimic the seasonal variation in water volume and water quality in order to maintain a broad set of ecological variables through “environmental flows.”
However, the recent shift by engineers to include climate and non-stationary management goals — described in Part 1 — presented a new potential means of connecting ecology and engineering, since ecologists were also reconsidering how important shifts in climate may be altering their natural resource management goals. The rise of decision scaling as a new tool for holistically exploring risk could be the link — the bridge across the waters. The stakeholder-driven aspects of decision scaling seemed to be an effective means for balancing multiple concerns and risks, and if the “breaking points” of ecosystems could be defined, perhaps a shared vision of sustainable water management could be achieved as well.
Through the National Socio-Environmental Synthesis Center (SESYNC.org), LeRoy Poff and John Matthews, both aquatic ecologists, decided to explore how to bring together engineers and ecologists who were jointly concerned about reconciliation and open to using decision scaling as a mechanism to find a joint means for practical and sustainable water management. The largest obstacle seemed to be that ecological complexity was hard to place within the essentializing language of engineering. Overcoming that obstacle would be the goal for the first of four workshops: what would should we use as simple, climate-relevant ecological “performance markers” of resilience within a decision scaling framework?
A Confluence of Visions and Practice
In 2013, SESYNC provided the opportunity to blend ecological and engineering approaches to sustainable water management by hosting four workshops in Annapolis, Maryland, USA, that would bring together a total of some 50 water thought leaders from all over the world and from a wide range of institutions and disciplines. Each workshop was designed to address a specific topic or area of tension, with the goal of establishing a new methodology and approach to “eco-engineering” water management that was grounded in decision scaling.
The result — eco-engineering decision scaling, or EEDS — developed over the course of two years, with additional contributions from economics, planning, geography, and history and archeology. EEDS represents both a tool and a framework for designing and operating water infrastructure given high uncertainties and risks. Unlike past frameworks that optimize efficiency and economic benefits, EEDS allows for a robust method of sustainable water resources management that can meet social as well as ecological needs. EEDS is a new common language, a bridge that spans historic divides by enabling the analysis of the simultaneous, shared risks between human and ecological needs and limits.
The Future of EEDS: Sustaining Waters through Uncertainty and Change
Although many people have been involved in developing EEDS, the approach is still new, and the methodology has not been tested through a large set of on the ground projects. The publication of a paper describing EEDS appeared September 2015, while extensions of the methodology are still appearing among collaborators and reviewers.
As a case study, the developers of EEDS applied the framework to an irrigation and flood control dam on the Iowa River in the United States. Increased flood risks in the region are forcing managers to assess potential flood-control management strategies. EEDS was used to evaluate the potential economic costs associated with altered climate regimes and to see how alternate actions for infrastructure construction, operations, and institutional or social measures would affect engineering and ecological performance indicators. The case study is further explained in the first video.
The future of EEDS could take many possible forms. Broadly speaking, it should be applied as part of Environmental Impact Assessments (EIAs) for water resources engineering projects, especially those that are already using or are considering decision scaling. EEDS could even reach outside of the water realm. Perhaps most importantly, EEDS can be combined with existing decision making frameworks such as adaptation pathways, a methodology developed by Deltares in the Netherlands, which explores sequences of policy options. EEDS could be used to determine the conditions for decision making “tipping points.,” The future of EEDS is examined further in the second video.
This website was developed thanks to the generosity of the National Socio-Environmental Synthesis Center (SESYNC), which is a joint initiative of the National Science Foundation (NSF) and the University of Maryland that is dedicated to accelerating scientific discovery at the interface of human and ecological systems. The Alliance for Global Water Adaptation (AGWA) is responsible for the development and maintenance of this site and its content.
Alex Mauroner led the design and layout of the site, along with direction of the videos and other content. Jody Hepperly assisted in implementation throughout. John Matthews was responsible for project conception and facilitation. This webpage was developed using Joe Workman's Foundation theme. We would like to thank his support team for their assistance during site development.
We would also like to thank the following individuals for their invaluable contributions:
- Melissa Andreychek
- Andres Baeza
- Casey M. Brown
- Kathleen C. Dominique
- Theodore E. Grantham
- Marjolijn Haasnoot
- Jonathan Kramer
- John H. Matthews
- Guillermo F. Mendoza
- J. Rolf Olsen
- Margaret A. Palmer
- N. LeRoy Poff
- Patrick Ray
- Mary Shelley
- Caitlin M. Spence
- Eugene Stakhiv
- Robert L. Wilby