Say what you like about America but, once Britain had wearied of empire-building, the USA pretty much invented the modern world single-handed. China is a great country now coming into its own. But, like its prosperous Asian neighbours their recent growth comes from leeching off American innovation and technology by doing cheaper (and sometimes better) knock-offs. The gung-ho, can-do attitude among Americans is infectious and goes some way to explain how a liquorice allsorts of immigrants could forge the world’s leading nation our of a wilderness.

But this has a down side. Because they never know when to quit, they take on just about any environment if there is money to be made.  They took simple windmill-pumped we;;s on isolated ranches and ramped this up in California’s Imperial & Central valleys, as well as Arizona’s Valley of the Sun to make those areas among the most productive agricultural acres anywhere. To achieve this, massive projects trapped, stored and transported water from the great rivers of the Southwest. The mightiest of these was the Hoover Dam across the Lower Colorado River, storing its 22,500 cu.ft./sec flow for use. That’s an acre-foot or 334,000 gallons every two seconds. While the huge Central Valley is watered by the snow melt on the lofty Sierra Nevada, Los Angeles, San Diego, the Imperial Valley and almost all of Arizona squabble over this bonanza. A century ago, when settlements were barely villages and Arizona barely a state, almost all of the water flowed unimpeded on to Mexico and the Sea of Cortez.

Those days are gone. Now only a muddy trickle makes it all the way. Technology like air-conditioning, automobiles and swimming pools make life in the sunbelt not just possible, but desirable, the explosion in population soon followed. As most of the land was desert, development could be expansive. As the weather was both hot and predictably, the growing of high-value crops was both easy and profitable. The original citrus groves soon gave way to more exotic produce. While California could satisfy its own water needs if it could shift water from the wet North to the dry South part of the state, the same can’t be said for its partner in Colorado River consumption: Arizona. Although the forested North of the state around Flagtaff receives rain- and snow-fall, the lower half is the Sonora Desert, normally capable of sustaining cacti, chaparral, lizards and the odd coyote. Water made the desert bloom and agriculture become big business. Cattle, lettuce, cotton, melons, greenhouse plants and even water-thirsty rice are grown in quantity. As a result, these soak up half Arizona’s water allocation—about 4 million acre-feet a year (about 1,3 trillion gallons or five weeks of flow in the Colorado River). Sprawling Phoenix now houses 4m of Arizona’s 6m residents and soaks up 1,4 million acre-feet a year (about 440 billion gallons or twelve fays of  Colorado flow.

These are intangible numbers. But measured against annual water use by an American family of five at one acre-foot, this means Arizonans consume water at twice that rate. Why should that be?

For a start, there are 615,000 swimming pools—one for every 10 residents. With an average area of 400 sq. ft., each pool loses 10,000 gallons each year from evaporation in Arizona’s arid climate. That’s a day’s flow of the Colorado right there. Double that for leakage. Add in evaporation and leakage from many artificial bodies of open water. Arrowhead Lakes(!) development includes over 43m sq.ft. of open water, losing over 1bn gallons of water each year. Nearby 10,000-acre fishing spot Lake Placid alone loses four times that.

Then there are the 185 golf courses that spray with 29bn gallons each year, most lost to evaporation. That’s almost two weeks of Colorado flow right there. Add in massive amounts of landscaping, even if much has been converted to heat-hardy native planting you start to see how Colorado’s bounty is literally running out. And we haven’t even started on 6m people’s domestic use of toilets, showers, washing machines, etc.

Because of several years of below-average rainfall/snowmelt upstream, an urgent conference called for December 12th in Las Vegas to square the impossible circle of satisfying all users in the Southwest of Lower Colorado water was something of a non-starter because the Arizona delegation could not agree on a position. Farmers, Municipalities, businesses and Indian tribal lands have stretched the state’s demand for river water well beyond that allocated and are furiously pumping artesian water out of aquifers that, being beneath a desert with 12 inches of rainfall, are not being replenished. Over 40% of Arizona’s water use now comes from this source, which is unsustainable.

This is where American’s irrepressible gung-ho/can-do would appear to lead them into an incipient car crash. Arizona offers a California-like climate at 2/3rds the price, so this will get worse. With the population forecast to grow by almost 50% to 9m people by 2025, attracted by lakeside living and golf courses, the problem of supplying adequate water appears intractable. California and Nevada are desperate to increase their own share of the Colorado, so any increase from that source seems unlikely. There are no other substantial rivers to tap. Yet the business machine keeps development sprawling ever wider across the Valley of the Sun, lawmakers run scared of not boosting their patch and the whole fragmented layers enshrined the US shibboleth of a constitution mitigates against anyone having clear authority to bang heads.

The fact that the last few years has seen waters supplies shrink certainly exacerbates the problem. But it has bot caused it. What caused it was a gravitational shift in American population from the Rust Belt to the Sun Belt and the blessing that the country’s second-biggest river flowed between the Sonoran and Mohave deserts. How this riparian car crash can be avoided is not clear. It is a hot spot when commerce and environment clash—and my money’s on the latter. I would not counsel investing in a lifetime membership of the Arrowhead Lakes Golf & Country Club as wise.