• Hamlet "Chips" Barry, manager, Denver Water
• Peter Gleick, president, Pacific Institute for Studies in Development, Environment, and Security, Oakland
• Peter Grubb, founder and president, Row Adventures, Coeur d'Alene, Idaho
• Bruce Hallin, manager, Water Business Development, Salt River Project, Phoenix
• Amy Souers Kober, Northwest communications director, American Rivers, Seattle
• Patricia Mulroy, general manager, Southern Nevada Water Authority
Much of the news we hear about Western rivers is dire: droughts in California and the Southwest, Western cities potentially running out of water, the uncertain impacts of climate change and continued population growth. So, today, how are our Western rivers doing?
Patricia Mulroy We're the canary in the mine shaft. When I look at the Colorado River, I know that by 2010, Hoover Dam could potentially not generate electricity. That Lake Mead is down - 90 percent of Las Vegas' drinking water comes from there. What do you do?
What about global warming? What are its impacts on Western rivers and water?
Mulroy Profound. The toolbox we've used for the last 100 years is not going to work.
Chips Barry The important component is what nobody can answer - what does global warming do to the volume and timing of precipitation? Nobody knows.
Peter Gleick We know a lot more about climate change than we used to. We know with a very high degree of confidence, for example, that in California, we're going to see a dramatic change in the timing of runoff. The future is not going to look like the past.
What specific impacts are we seeing now?
Bruce Hallin If you look at the tree-ring studies, stream-flow reconstructions, what they're telling us in Arizona is that the year 2002 was the lowest stream flow ever recorded since the 1300s.
Mulroy A lot of the storage for the Colorado River system is in snowpack, and that gradual melt of the snow isn't happening anymore.
Gleick The Colorado worries me the most. We know we've already given away too much water in the Colorado. We have to fundamentally change our basic assumptions, and we aren't doing that.
Don't a lot of people think, Well, if we run short of water in Los Angeles or Phoenix, we can pipe it in from Alaska or Canada?
Barry Pumping water takes enormous volumes of electricity. Something like 25 or 30 percent of all the electric consumption in California is attributable to the pumping of water.
Hallin Water requires energy, and energy requires water.
So is water the new oil?
Gleick Oil is not renewable; water is. That's an advantage. There are substitutes for oil, though. And there are no substitutes for water. That's a big disadvantage.
But on a per-capita basis, we use less water than we did 20 years ago, right?
Hallin I look at the city of Phoenix, and over the last 10 years, we've had close to a 300,000 increase in population. But water demand overall has remained constant. We have better technologies; people are more cognizant of their water use.
Gleick That's true in Los Angeles and San Francisco.
Hallin We've had new plumbing codes that require these low-water-use fixtures in Arizona for over 20 years. We've taken a long-term planning viewpoint because we know we live in an arid environment and we will be facing a drought.Even so, people argue that the West will always have water problems because we've built big cities like Las Vegas and Phoenix in the desert.
Mulroy You know what? Las Vegas exists. It's where the jobs are. It's where the people are. And southern Nevada industry is the most water-efficient industry there is.
Hallin People like living in the desert. It's a very good quality of life.
Gleick It's not a question of taking down Las Vegas or Los Angeles or Albuquerque or Phoenix and building them back somewhere where there's water. That horse has left the barn.
What about dams? It's argued that because of global warming, we'll need to build new dams to store more water.
Barry Historically in the West, one of the answers to a highly variable natural supply of water was water storage. You stored water in times of plenty to get through times of drought. If we're going to see more variation, maybe we need to think about additional storage.
Gleick Dams brought enormous benefits to the western U.S. They also brought some unexpected costs, mostly environmental.
Amy Souers Kober People ask American Rivers all the time, "Well, are we going to need to build more dams?" And I think that that's not even the right question to ask right now.
At the same time, there's a strong push to tear down some dams.
Gleick People don't know this, but in the United States, more than 500 dams have been removed over the last 10, 15, 20 years. Almost all of them small, almost all dangerous, because they were badly built or environmentally destructive.
Souers Kober One case is the Elwha River flowing out of Olympic National Park. Pretty much the only things wrong with it are these two outdated, unsafe dams. We're just trying to get the money to remove the dams and restore the river.
Why are wild rivers important?
Peter Grubb There's something really visceral about rivers, particularly whitewater rivers. Part of that is you're pushed along in the current and there's not a lot you can do about that. You can't take a time-out in the middle of the rapid. It's a good lesson in commitment.
And they're economically important too.
Grubb In Idaho, where I live, it's huge. It's safe to say that in towns like Riggins and Salmon and Stanley, rafting has gone a long way toward replacing the logging economy that was there 20 or 30 years ago.
Is the West facing a water crisis?
Souers Kober I think we are in a crisis.
Gleick I do a lot of work internationally. A billion people without access to safe drinking water is a crisis. What we see right now in the western United States isn't the same kind of crisis. But we don't want a crisis. When we're in crisis mode, people make stupid decisions.
How do we avoid the stupid decisions? How do we change how we think - and act - about Western rivers and water?
Souers Kober Know where your water comes from. I think so many of us are cut off from that reality, and we don't realize that we're drinking rivers, we're drinking lakes, and we have rivers flowing in our veins. I think our quality of life depends on having clean, free-flowing rivers.
Mulroy What we have to do is create a new ethic around water. You have to make that transition that there's a new tomorrow. There's still a mind-set that "I'm man and I can make nature adapt to me" - and that needs to change. Embrace the fact that you live in a desert. I've often said it would be tantamount to moving from Florida to Alaska and insisting on wearing shorts or a bathing suit in March. It makes no sense.
Gleick Rivers aren't just for drinking water. That's not what the 21st-century idea of rivers will be. It's drinking water and irrigation water and recreation and healthy fisheries and what rivers used to be.
Souers Kober Rivers can be restored, and it's such a hopeful thing. You can see it with your own eyes, and it doesn't necessarily have to take very long. Sometimes you talk about how we restore rivers, but in the end, sometimes it's the rivers that restore us and that can just make us feel whole and healthy again.