A street with bike lane in a stalled new housing subdivision in on the south end of Las Vegas, Nevada. Automatic sprinkler systems are already installed. Las Vegas receives 90 percent of its water from the Colorado River, drawn from nearby Lake Mead.

A young onion picker ties rubber bands around the bunches of scallions in a Sonoran field not far from Ejido Luis Encinas Johnson on a late autumn afternoon, near the end of a day that began at 4 am.

Monica Gonzáles, the daughter of the traditional chief of the Cucapás, signs her name to a citation given to her from Mexican government officials, backed by armed marines, preventing her people from fishing for corvina (sea bass) in the nucleus zone of the Upper Gulf of California Biosphere Reserve. A recommendation from the Commission of Indigenous Subjects for the Presidency of the Republic that the Cucapas be allowed to fish in the zone because of their ancestral traditions was disregarded.

Corvina (a kind of sea bass) are unloaded from a panga on the Rio Colorado to be gutted and cleaned at a Cucapá fishing camp near the mouth of the Colorado River at the Gulf of Mexico. The Cucapás have had to battle Mexican government authorities and non-native fishermen to continue to use their traditional fishing grounds for the annual winter corvina harvest, which has been the tribe’s main source of income for each year, because the area is now considered part of the nucleus zone of the Upper Gulf of California National Biosphere Reserve.

A Cucapá youth fishes for crabs near the mouth of the Colorado River in Mexican state of Baja California Norté, waiting for his father to return in his boat from curvina fishing. Because the Colorado River itself no longer reaches the ocean because of diversions upstream in the United States, the water at the river channel's mouth is a brackish mix of sea water and irrigation runoff.

Mexican biologist Alejandra Calvo holds a Wilson's warbler caught in a research net erected in the Laguna Grande habitat restoration area in the Colorado River Delta.

The Blue Angels, the United States Navy's aerobatic flight group, performs a flyover of Hoover Dam as part of the celebration there of the centennial of the U.S. Bureau of Reclamation, the federal entity which built the dam in the 1930's

Intake pipes into Lake Mead which provide Colorado River water for nearby Las Vegas, Nevada. The city's water agency will be spending well over $1 billion to build a new intake and attached pumping station as insurance against continuing decline in the level of Lake Mead. The new intake will be near the bottom of the lake and would still provide water to Las Vegas, even if the lake level dropped below the intake towers at Hoover Dam, after which water could not be delivered downstream.

A boy carries water to the beach near the Colorado River headwaters at Grand Lake, Colorado, where he and his playmates are building a dam out of sand.

Setting up the sound system for an outdoor December wedding at the Papago Golf Course, in Phoenix, Arizona,.

The Big Surf water park in Tempe, Arizona, with the oldest recreational wave machine in the United States. The city receives Colorado River from Lake Havasu, over 300 kilometers away, via the Central Arizona Project Canal.

A crowd of mostly Navajo people spend the late afternoon of U.S. Independence Day in 2004 on a part of Lake Powell previously submerged in water when the reservoir dropped to its lowest level since the lake had been filled in the 1960's. As of spring 2015, Lake Powell is again in almost the same condition.

Alberto Ramirez, 6, a local boy who has come with his family to enjoy the Colorado River the day after its flow slowly submerged a road across what had been a dry riverbed the 1990's. For eight unprecedented weeks in 2014 a simulated spring flood of water was released into the river channel from the Morelos Dam at the U.S./Mexico border, where the vast majority of Mexico's allotment of the river is diverted into giant canals, mostly for irrigation. The so-called "pulse flow" was an attempt to restore lost habitat along the riparian corridor.

A crushed plastic bottle lies in the dirt, along with bird and mammal tracks, at the end of the Wellton-Mohawk canal, which carries saline irrigation runoff from southern Arizona into the Mexican state of Sonora. If the runoff were allowed to flow into the Colorado River it would raise the salinity above the level allowed by a treaty between the United States and Mexico, but unexpectedly, it created the finest remaining wetland habitat on the lower Colorado River.

A broken sprinkler on Pebble Road, near the intersection with Green Valley Parkway in Las Vegas, Nevada. With an average annual rainfall of only 10.4 cm, much landscaping can only survive with regular irrigation.

Built on what was once the land of the Yavapai people, the town of Fountain Hills, built by Robert P. McCullough (who moved the old London Bridge to Lake Havasu) has the world's fourth tallest fountain. EPCOR, a private company, provides Colorado River water from the Central Arizona Project Canal to the community.

Harvesting head lettuce outside of Yuma, Arizona, where agriculture, which grows winter vegetables for the entire country, is almost entirely dependent on the Colorado River for irrigation.

Fresh local oranges, mostly from groves irrigated with Colorado River water brought from over 300 km away.

Hoover Dam and Lake Mead were the center of attention at the annual Colorado River Water Users Association conference that just ended earlier in the day that this picture was taken, in nearby Las Vegas.

Local environmentalist Juan Butrón pretends to drink water from the dry channel of the Colorado River as he goes looking for the leading edge of the slowly moving pulse flow of water from the Morelos Dam, a few kilometers upstream. Within a few hours it would reach this spot, though in less than two months the riverbed would once again be dry.