where does the rio grande river start in colorado
Rio Grande The Rio Grande rises in the western part of the Rio Grande National Forest in the U.S. state of Colorado. The river is formed by the joining of several streams at the base of Canby Mountain in the San Juan Mountains, just east of the Continental Divide. From there, it flows through the San Luis Valley, then south into the Middle Rio Grande Valley in New Mexico, passing through the Rio Grande Gorge near Taos, then toward Española, and picking up additional water from the San Juan-Chama Diversion Project from the Rio Chama. It then continues on a southerly route through the desert cities of Albuquerque and Las Cruces to El Paso, Texas, and Ciudad Juárez, Chihuahua. In the Albuquerque area, the river flows past a number of historic Pueblo villages, including Sandia Pueblo and Isleta Pueblo. Below El Paso, it serves as part of the border between the United States and Mexico.
Colorado River Flows at the mouth of the river have steadily declined since the beginning of the 20th century, and in most years after 1960 the Colorado River has run dry before reaching the Pacific Ocean.[63] Irrigation, industrial, and municipal diversions, evaporation from reservoirs, natural runoff, and likely climate change, have all contributed to this substantial reduction in flow, threatening the water supply for the future.[64][65][66] For example, the Gila River – formerly one of the Colorado's largest tributaries – contributes little more than a trickle in most years due to use of its water by cities and farms in central Arizona.[67] The average flow rate of the Colorado at the northernmost point of the Mexico–United States border (NIB, or Northerly International Boundary) is about 2,060 cubic feet per second (58 m3/s), 1.49 million acre feet (1.84 km3) per year – less than a tenth of the natural flow – due to upstream water use.[68] Below this point, the remaining flow is diverted to irrigate the Mexicali Valley, leaving a dry riverbed from Morelos Dam to the sea that is supplemented by intermittent flows of irrigation drainage water.[69] There have been exceptions, however, namely in the early to mid-1980s, when the Colorado once again reached the sea during several consecutive years of record-breaking precipitation and snowmelt.[70] In 1984, so much excess runoff occurred that some 16.5 million acre feet (20.4 km3), or 22,860 cubic feet per second (647 m3/s), poured into the sea.[71]