American Water
American Water  
Corporate Responsibility
HomeContact UsPress RoomInvestor RelationsCorporate ResponsibilityService Line ProtectionProducts & ServicesCareersLearning Center

Climate Variability

Climate variability introduces an additional level of uncertainty about our future water resources. According to the U.S. EPA, the growing greenhouse gas (GHG) buildup in our atmosphere is creating increased climate and weather unpredictability. For example, precipitation and runoff are likely to increase in the Northeast and Midwest in winter and spring, and decrease in the West, especially in the Southwest, in spring and summer, according to the U.S. EPA.

Most of the infrastructure designed to ensure U.S. water quality is based upon the historical trends of the timing, temperature, quantity of precipitation, and water flow. Climate change, however, will likely affect one or more of these variables in almost every area of the country, resulting in disruption of water quality, unless adequate contingency planning is made.

There are many uncertainties associated with changing climate patterns and its impact on water, but there is little doubt that climate variability could disrupt water quality and supply without adequate planning and risk assessment. American Water’s expertise and risk management processes are helping us to plan for this new water reality. We build climate change considerations into our approach to evaluating future supplies, managing risks, and preparing for weather-related events in order to determine the full requirements of our water systems.

Our approach uses Comprehensive Planning Studies (CPS) to evaluate the condition of water systems and to project future needs and impacts. Climate change risk is built into the CPS so that we are better able to understand the future requirements of our water systems. We supplement our CPS with other tools to help plan for some of the more extreme impacts of climate change, including severe drought. For example, we develop Water Conservation Plans and Drought Response Plans to greatly reduce usage in times of severe drought. We develop Emergency Response Plans in response to extreme flooding in order to protect communities and our facilities.

Read more about how we are actively addressing the climate variability challenge in our Energy and Water, and Enterprise Risk Management sections.


“Throughout the latter half of the 20th century, the common refrain about water challenges in America went something like this: ‘Water quantity is the problem of the West, and water quality is the challenge of the East.’

“The East got a loud wake-up call at the dawn of the new millennium. By 2001 the Atlantic seaboard was panicked by a searing multi-year drought that drew rivers and water supply reservoirs to their lowest levels in recorded history. Large metropolitan areas found themselves within months of running out of water.

“The recent Eastern drought -- or for that matter, the Big Dry of the last decade in the Colorado River basin of the West -- could simply be the lowest dips in the long-term precipitation record, or a bellwether of climate changes to come. For water managers, the conclusion is the same: from Maine to Florida and Georgia to California, too many urban water supply systems are vulnerable to climate variability. With each new year, as the accuracy of climate predictions increases and real-world evidence of a shifting climate mounts, we are coming to realize that we’re going to have to expect more of this variability and less reliability in our water supplies. The weather just ain’t what it used to be.

“This report from American Water highlights the appropriate responses. Water managers need to start integrating climate change projections into their water supply plans. They should not just plan for drought management; they should expect it and be fully ready to implement it. They should maximize water use efficiency and conservation measures; it is easier to maneuver a lighter boat than a heavy one when trouble arises. They should protect the “natural infrastructure” that buffers us from extreme hydrologic variation: healthy watersheds, wetlands, floodplains. They should leave enough water for Nature.

“We can manage our way through this uncertainty. We must. People and nature are counting on us.”

Brian Richter, Managing Director, Global Freshwater Program, The Nature Conservancy