Today, those verdant times are but a distant memory. The mighty Colorado River has since been harnessed by huge dams, steered into farmers' fields and dispatched to booming cities. Upon reaching the delta, the once robust watercourse is just a trickle; only rarely does it touch the gulf's northern fringe.
Until recently, however, it was unclear just how much had been lost when the Colorado River Delta dried up. Enter Karl Flessa, a UA geosciences professor and longtime delta researcher who started crunching the numbers--and arrived at a startling conclusion. According to Flessa's groundbreaking research, draining the delta comes in at a whopping annual cost of $2.4 billion dollars.
"It's not that the United States alone is losing $2.4 billion dollars a year," he explains. Instead, Flessa says that communities on both sides of the border lose countless services once provided by the delta, from habitat for threatened species to nurseries for commercial fish such as the totoaba, once common in the Gulf of California.
"I looked at the difference in ecosystems," he says, "estimating what used to be there, compared with what's there now. And I came up with a big number that's admittedly not precise at all. But the key point is that the number is not zero. There is a value lost in the delta."
By applying a dollar figure to lost natural resources, Flessa is tapping into a concept that hit the world stage with a pivotal 1997 article in the journal Nature. In the story, scientists discuss "ecosystem services" and "natural capital stocks" crucial to the Earth's survival. In a sense, this means placing a price tag on such things as clean air, clean water and clear vistas.
Take swamps, for example. They provide vital services--estimated to be worth billions of dollars--by helping to control floods, holding waste products and cleansing water. Since such "ecosystem services" contribute to the welfare of mankind, they also represent a concrete portion of economic value to the total planet.
How big is that portion? Authors of the Nature article suggest in 1997 that the value of such services across the globe averaged around $33 trillion annually. That compares to a global gross national product of approximately $18 trillion per year. In other words, the value of natural ecosystems far outweighs the value of things we produce, often at nature's expense. As a result, say these scientists, it makes financial sense to protect forests, swamps and even the Colorado River Delta.
Of course, value is also gained by using river water that once nourished the delta, Flessa says. "There's the value of agricultural products, the value of cities that depend upon Colorado River water, including Tucson. What I'm saying is that users--from farmers to cities--should pay for the consequences to the delta ecosystem."
So, Flessa decided to put a price tag on those consequences. Armed with a fellowship from the campus-based Udall Center for Studies in Public Policy, and with assistance from the UA's Institute for the Study of Planet Earth, he began scouring maps and public documents. "I was trying to determine how many acres of land were used for agriculture in the lower Colorado, around the Yuma-Somerton area," he says. "I also wanted to find out how many acres of land are used for agriculture in Mexico. Then I figured out the area of the Gulf of California that used to be infused by freshwater flow (from the Colorado River)."
He needed to determine the value of habitats in the entire lower Colorado River area, how much of the delta was originally floodplain, how many acres were mixed saltwater/freshwater areas called estuaries and how much of the area had been desert. Then, Flessa started adding up the numbers--placing economic values on "ecosystem goods and services" that would be provided by the delta if it were intact--and presented his findings to a recent Gulf of California conference.
"It's a rough, first attempt to value things that aren't valued in a traditional economic sense," he says. "But nevertheless, it's expressing value in a way everyone understands--in dollars."
Lots of dollars, in fact. Broken down, it becomes clear just how much nearby economies have suffered from the delta's demise. For example, depletion of the fresh and saltwater nurseries has decreased sport-fishing species in the gulf, and perhaps lowered shrimp catches. But other costs, such as those related to the loss of trees in the delta, aren't so obvious. Trees store carbon, preventing it from being released into the atmosphere as carbon dioxide.
"This isn't part of the traditional market concept," Flessa says, "and carbon sequestration among the cottonwoods and willows of the delta wouldn't line anyone's pocket. But it would be a benefit to society as a whole, in a sense of decreasing the amount of CO2 in the atmosphere." CO2 is considered a leading contributor to global warming.
But coming up with a dollar amount wasn't the end of the story. Now that Flessa has placed a figure--however broad--on the depleted resources of the delta, it may be time to pay up, and put the money to work. "Taking water out of the river and away from natural ecosystems decreases the benefit to us as a society," he says. "The way that society has normally dealt with this is simple: Those taking the resource should pay for it. The user should pay.
"When you or I use water, or agricultural concerns use water, part of the price for that water should be replacement costs for the ecological benefits that are lost. Even if we only charged users $1 an acre-foot, that comes out to about a penny for 3,000 gallons." (An acre-foot is an agricultural measurement, meaning the amount of water that would cover one acre to a depth of one foot.) "If we summed that over a year, you would generate a fund of approximately $14 million annually."
In turn, that money might help bring the delta back to life. "You could then create a pool of money for restoration of those habitats," he says. "So the user is essentially paying for the cost of habitat restoration.'
This approach might involve something simple, such as paying a farmer not to plant for one year, and then using the extra water to replace bird habitat. "It can be broken down into particularly practical terms," he says, "such as duck hunting or bird watching. For suppliers and outfitters, those are real benefits that improve communities on both sides of the border."
Or, the money might go toward re-establishing marine nurseries that could support commercially important species. Regardless, Flessa says it's time for new thinking about the cost of depleting natural resources such as the delta. "I'm not suggesting--nor do it think it's practical--to completely restore this habitat," he cautions. "That's not going to happen. But we could certainly restore a certain percentage of what was there. And I think this approach moves the discussion to broader ground."
Or at least across the broad Colorado River Delta. And who knows? Perhaps verdant green lagoons will come to accent this once lush region once more.