New Information Shows How Climate Change Will Affect Water

WASHINGTON, DC, October 6, 2008 (ENS) - More intense storms will threaten water infrastructure and increase polluted stormwater runoff as climate change impacts water resources across the United States, the U.S. Environmental Protection Agency warns in a proposed climate and water strategy issued Thursday.

Shorelines will move as a result of sea level rise, and changes in ocean chemistry will alter aquatic habitat and fisheries, the agency said.

Warming water temperatures are likely change contaminant concentrations in water and alter the uses of aquatic systems, the EPA strategy document projects.

The document adds that new patterns of rainfall and snowfall are expected to alter water supply for drinking and other uses and lead to changes in pollution levels in aquatic systems.

Heavier precipitation in tropical and inland storms will increase the risks of flooding, expand floodplains, increase the variability of streamflows (i.e., higher high flows and lower low flows), increase the velocity of water during high flow periods and increase erosion," according to the strategy document.

"These changes will have adverse effects on water quality and aquatic system health. For example, increases in intense rainfall result in more nutrients, pathogens, and toxins being washed into waterbodies," the document states.

As a result, the strategy advises, water managers will need to expand efforts to plan for and respond to extreme weather events resulting from climate change, including storms, an excess of water, and a lack of water.

"Water is key to clean energy and climate change," said Benjamin Grumbles, EPA's assistant administrator for water. "Our water and climate strategy charts a course for timely and practical action, connecting the dots, drops, and watts for coordinated, sustainable results."

EPA's "National Water Program Strategy: Response to Climate Change" describes steps for managers to adapt their clean water, drinking water, and ocean protection programs, but it is not a rule or regulation and is not legally binding.

"Agency decision makers remain free to exercise their discretion in choosing to implement the actions described in this strategy," says Grumbles.

While "significant uncertainty about the exact scope and timing of climate change-related impacts on water resources," remains, the strategy represents "an initial effort to evaluate how best to meet our clean water and safe drinking water goals in the context of a changing climate," Grumbles says.

The ideas and response actions outlined by the strategy are the product of a cooperative effort among EPA water program managers in national and regional offices.

In a change of policy for the Bush administration, the document states that, "A long-term, international investment in scientific study of the Earth's climate is now resulting in a scientific consensus concerning climate change and its impacts on water resources."

For most of the time since the Bush administration took office in January 2001, officials denied the existence of a scientific consensus on climate change.

The EPA still does not regulate greenhouse gases such as carbon dioxide, although several regional groupings of U.S. states, Mexican states and Canadian provinces have begun to document greenhouse gas emissions and trade emissions permits.

Now the EPA strategy document states, "EPA Administrator Stephen Johnson has identified 'clean energy and climate change' as a top agency priority, and EPA national and Regional offices are working to define strategies and actions in this area."

The new strategy focuses on 44 specific actions for the National Water Program to take in responding to climate change.