Mohammed Mahmoud, PhD, Senior Policy Colorado River Programs Analyst/Chair, Water Utility Climate Alliance
How does one plan for climate change? After all, the impacts vary with respect to their intensity, duration and frequency. This range of climate change is especially acute for water utilities. Some impacts can be quite sudden or unexpected in their intensity — such as extreme weather events – and other impacts can slowly emerge and grow over time – such as increased warming and prolonged droughts.
Planning for climate change therefore takes place in consideration of short-term, mid-term and long-term impacts.
In contrast to the current pandemic we are all experiencing, planning for climate change is similar to how public health and medical experts progressively handle an infection:
- Treat the symptoms (short-term).
- Diagnose underlying conditions (mid-term).
- Prevent disease and mitigate against future infection (long-term).
Short-term – Immediate Action (treating the symptoms)
Short-term impacts of climate change can happen suddenly and even if anticipated, can be more dire than expected. These types of impacts represent emergencies such as damage to water infrastructure from short duration and intense weather events.
Planning for short-term climate change impacts relies heavily on forecasting tools that provide high accuracy and precision forecasts in the near-term. In the case of CAP and the Colorado River Basin that means looking at:
- Daily/weekly/monthly water supply data (precipitation, temperature, Snow Water Equivalent (SWE), streamflow) from the Colorado Basin River Forecast Center and the U.S. Bureau of Reclamation;
- Climate indicator forecasts (such as El Nino Southern Oscillation) from the Climate Prediction Center; and,
- Regional drought conditions from the U.S. Drought Monitor.
Analyzing near-term forecasts can provide insight on potential short-term climate impacts or flag conditions that may exacerbate a short-term climate impact.
Strategies that address short-term impacts may be reactionary and temporary, focusing on crisis management (with a lifespan measured in months). Examples of short-term solutions CAP has implemented in the past to address the seasonal impacts to water supply due to hotter and drier conditions include Intentionally Created Surplus (ICS) generation through conservation and voluntary contributions of water volumes to preserve the integrity of Lake Mead storage.
Mid-term – Planning biased with today’s information (diagnosing underlying conditions)
When it comes to the mid-term timescale for climate change, there can be significant uncertainty to the duration, intensity and frequency of climate impacts. This is because most mid-term impacts of climate change go beyond sudden events (like extreme weather). Rather, they include prolonged implications that occur over long periods (such as persistent drought). The uncertainty arises from a planning perspective because it is unclear how long a climate impact could last — will it end up being a short-term or long-term implication?
For example, we know we are currently in the midst of a sustained drought on the Colorado River system, and while we don’t know how long it will last, we are collecting information on it (e.g. magnitude of reductions to precipitation, snowpack and streamflow) so there is higher confidence in the decision-making that puts adaptation and mitigation strategies in response. We are taking advantage of analyzing current data to put the best strategies in place, regardless if the impact ends up being a short-term or long-term one.
Adaptation strategies for climate change in the mid-term therefore can be in place for years, as long as they remain relevant. There are numerous sources of information that synthesize past and current data for the benefit of climate change planning beyond the short-term, such as the Colorado River Climate and Hydrology State of the Science Report. A prime example of when CAP and other Colorado River water users used this type of current data for future planning and strategy implementation is the analysis of multiple hydrologies (including climate-downscaled hydrology and dry-biased ‘stress test’ hydrology) for the purpose of supporting the implementation of the Drought Contingency Plan.
Long-term – Analysis that leads to adaptation processes (preventing disease and mitigating against future infection)
Long-term impacts of climate change represent persistent trends or permanent shifts that are significantly different from the past. This can include multi-decadal droughts and sustained warming that continues unabated. As such, both long-term impacts of and solutions for climate change occur over the span of decades. The long-term impact can become a new “normal” and the corresponding solution may put in place a new way of conducting business or operations.
Long-term solutions to climate change impacts encompass policy changes, new business directives and permanent work adjustments that acknowledge paradigm shifts. Planning for climate change in this timescale requires tools that allow us to project into the future using the best information we have available. We do that at CAP through modeling and analysis by utilizing simulation models like CRSS (Colorado River Summation System) or by partnering with others on modeling efforts (e.g. the NASA-funded collaboration between CAP and Arizona State University). These tools can then help put into action solutions that allow us to be more resilient to future impacts of climate change, which CAP is currently doing by implementing its Climate Adaptation Plan and participating in the Arizona Reconsultation Committee (to work toward the development of new guidelines beyond the 2007 Interim Guidelines).