CH2M HILL’s Systems Thinking: Sustainable Water in a Changing Climate
People depend on government agencies and municipalities to efficiently manage their water resources for sustainable uses and environmental protection. Water infrastructure currently designed to cope with business-as-usual frequency and severity of snow melts, storms and tides may now be inadequate to service current populations, let alone growing populations. In some areas, extended droughts, reduced snowpack and declining basin run-off have demonstrated the variability and potential vulnerability of agricultural, industrial and community use to changes in water supply.
New tools now exist to look at a watershed comprehensively as a system. People don’t naturally think in systems, so it helps to have tools and processes to visualize how pieces of the system fit together. As our water needs have evolved over time – from simple farms near rivers to complex cities relying on a range of water sources – the inter-relationships among components of watershed systems can be obscured. To optimize use of limited resources, we must understand the inter-relationships that enable the whole system to function more efficiently. Once we define the system, we can assess water management, evaluate risks and model climate change to create a set of alternatives for dealing with future water supply and infrastructure risks and requirements. This approach can operate on any scale and incorporates a multiple-resource management view.
Systems Thinking at the Regional Scale
Spanning parts of the seven states of Arizona, California, Colorado, New Mexico, Nevada, Utah and Wyoming, the Colorado River Basin is one of the most critical sources of water in the western United States. The Colorado River and its tributaries provide water to more than 30 million people for municipal use and supply water to irrigate nearly 4 million acres of land. The River and tributaries are also the lifeblood for at least 15 Native American tribes, seven National Wildlife Refuges, four National Recreation Areas and 11 National Parks. Hydropower facilities along the Colorado River provide more than 4,200 megawatts of generating capacity and offset use of fossil fuels. In response to increasing demands and potentially reduced supply, the U.S. Bureau of Reclamation, in collaboration with the seven Colorado River Basin states and the involvement of multiple stakeholders, is conducting a comprehensive study to assess current and future imbalances in water supply and demand in the Basin and adjacent service areas. It is also exploring opportunities on how to resolve those imbalances.
To quantify future supply and demand imbalances, given the high level of uncertainty regarding future conditions, the study has developed scenarios reflecting a range of plausible futures for the Basin. We began by working with stakeholders to identify factors expected to influence supply and demand over time. The water supply scenarios are based on streamflow variability as indicated by historical streamflow records from the past 100 years, reconstructions of the long-term “paleoclimate record” using data from an extended past and projections of future climate through global climate models.
Water demand scenarios incorporate social, economic and governance factors. These potential demand scenarios include continuation of current trends and policies, economic slowdown with reduced growth in the basin and expansive economic growth with increases in population, technology development and environmental awareness.
Any combination of the water supply and demand scenarios is possible and could result in different plausible future conditions. For example, increased energy demand in an economic growth scenario, combined with limited water supply in a climate projection scenario, would mean less water available to support greater demand driven by higher population. As the resource becomes more limited, broader sustainability questions arise, including who bears the burden of paying for infrastructure adaptations, equitable access to water and trade-offs between different water use types. By visualizing future scenarios, stakeholders can reach a deeper understanding of these issues and begin to plan for the future.
Systems Thinking at the Local Scale
Systems thinking embraces connections among resources, such as water, energy and carbon. This comprehensive approach is scalable, meaning that systems thinking works for one facility as well as it works for the Colorado River Basin regional study.
A water treatment facility must process whatever comes down the pipe, literally. Pumping and treating water takes a significant amount of energy, and some of this energy is spent processing wastes that are difficult to separate and treat. Variable energy prices, driven by costs of coal, oil, natural gas and other petroleum-based sources, make it difficult to predict the cost of treatment – costs borne by ratepayers – from year to year.
The Johnson County, Kansas, wastewater treatment facility has replaced traditional energy sources with nontraditional sources, achieving multiple benefits.
The upgrade for their biosolids facilities at Douglas L. Smith Middle Basin Wastewater Treatment Plant includes a new fat, oil, and grease (FOG) waste receiving and processing system designed to operate in a harsh winter environment and support Johnson County’s aggressive waste management program. The facility will beneficially reuse this energy-rich material and reduce average miles traveled by FOG waste haulers by 40,000 miles annually, thus saving 8,000 gallons of fuel and a reducing carbon dioxide equivalent (CO2e) emissions by 80 metric tons. The upgraded biosolids facility will combine treatment plant biosolids with food processing and restaurant FOG wastes to create enough methane gas to run two electric cogeneration units, each producing one megawatt of power. The power output will be sufficient to handle most of the plant’s electrical needs at an annual power savings of more than $500,000. Greenhouse gas (GHG) emissions will be reduced by 9,700 metric tons in CO2e emissions annually.
Partnerships Today to Address Issues Tomorrow
Fundamentally, these two vastly different projects illustrate that questions of energy, economy and water are intertwined. Ultimately, energy required to treat, store and move water cannot be separated from infrastructure decisions and planning. At the same time, reducing emissions from those energy sources, thereby reducing climate change effects over time, is advantageous for long-term water supply stability. As Steven Solomon wrote in Water: The Epic Struggle for Wealth, Power and Civilization, “One recurrent lesson of history is that societies that passively live too long off old water engineering accomplishments are routinely overtaken by states and civilizations that find innovative ways to exploit water’s ever-evolving balance of challenges and opportunities” (2010, HarperCollins).
The possibilities for creating a new, more robust future through innovative partnerships is one of the fruits of systems thinking. If, for example, the Johnson County wastewater treatment facility didn’t have an energy source on hand, could they have used surplus energy from a neighboring industrial process or gas from a landfill? Using approaches and tools like scenario planning helps us understand and visualize our plausible futures, within a single town or throughout a watershed, and collectively work together to address sustainability risks and challenges. For the Colorado River Basin, we hope that visualizing future scenarios, and understanding potential outcomes, strengthens partnerships to develop implementable solutions and opportunities to create a more sustainable future.