As climate change promises to alter precipitation patterns and bring more weather extremes, the federal agencies responsible for managing much of the country's water resources -- from dams to ports to irrigations systems -- are calling for better monitoring, forecasting and communication.

The U.S. Army Corps of Engineers and the Bureau of Reclamation released a report that surveyed operators on short-term water management decisions and their needs in the face of a changing climate.

The report was drafted with collaboration from the National Weather Service through the Climate Change and Water Working Group. It follows a 2011 report on long-term planning needs.

Water system managers need good information about current conditions, as well as information about upcoming storms or droughts. While climate change is unlikely to affect truly short-term decisions -- made looking forward minutes and days -- it will likely have impacts on planning done weeks and months ahead of time, the report says.

"In a daily, hourly basis, climate change isn't affecting those operations," said David Raff, a hydrologist with the corps' Institute for Water Resources and lead author of the report. "But when you look out into weeks and months in terms of drawing down a reservoir to allow snowmelt to fill the reservoir later in the season for water supply or irrigation ... climate does begin to play a role."

Making sure that areas are well enough monitored is key to dealing with those changes, the report says.

"The most critical and biggest thing that we heard from our operators were maintaining and expanding observational networks," Raff said. "To be able to do their jobs, they need to make sure that there are observations as to what is going on with their river, what is going on with rain in their watershed."

The report also calls for improved forecasting that gives managers a sense of how likely certain potential weather events are, and better communication about what can and can't be expected from such forecasts.

The situation currently playing out on the Mississippi River amid low water levels is a prime example of the challenges agencies like the corps are likely to face in the future.

The drought that has gripped much of the country reduced flows into the river. For months now, the barge industry and the corps have been poring over forecasts trying to anticipate when key stretches of the river might drop too low to allow barges the requisite 9-foot draft for navigation. Different reactions to those forecasts, as well as the corps' concerns about impacts that water releases from upstream reservoirs could have on its obligations to provide water for irrigation and other needs later in the season, have at times left industry and the federal agency at odds.

"These are the types of events -- these extremes -- that test operations, and these are the most important areas that we get the best available science," Raff said.