Gila River

About the Gila River

• The Gila River rises in the Gila Wilderness within New Mexico's Gila National Forest, a roughly 558,000-acre wilderness that in 1924 became the world's first area of land ever designated as wilderness, 40 years before the 1964 Wilderness Act.1
• From there the river flows roughly 500 miles west to meet the Colorado River near Yuma, Arizona, though large irrigation diversions below Phoenix typically drain it dry long before it gets that far.2
• In New Mexico the Gila remains the state's last free-flowing river, known for hosting one of the highest concentrations of breeding birds in North America and for fishing, hunting, backpacking and horseback riding along its upper reaches.32

This report follows 250 miles (403 km) of the Gila River across 3 watershed segments, from Upper Gila-San Carlos Reservoir downstream to Upper Gila-Mangas. At the lower end of the report the river drains about 12,186 square miles. Named tributaries joining it here include the San Francisco River, San Simon River, East Fork Gila River, Eagle Creek and West Fork Gila River. 9 gauges with at least 26 weeks of daily flow cover 1910 to 2026.

From the archive: NHDPlus river network, WBD watersheds, NHD waterbodies, TIGER urban areas and the report's gauges.

From the headwaters down

Each watershed segment in order, with last week's flow rated against the same week in 1991–2020.

1. 1

   Segment 1: Upper Gila-San Carlos Reservoir

   771 cfs last week much above normal.

   Median conductance 680 µS/cm in the 2020s.

2. 2

   Segment 2: Upper Gila

   202 cfs last week much above normal.

   Median conductance 283 µS/cm in the 2020s. Rain over the last 3 months: 142% of normal.

3. 3

   Segment 3: Upper Gila-Mangas

   285 cfs last week much above normal.

   Median conductance 402 µS/cm in the 2020s. Rain over the last 3 months: 123% of normal.

Culture

• Gila Cliff Dwellings National Monument, established by presidential proclamation on November 16, 1907, protects caves above the West Fork of the Gila River where people of the Mogollon culture built rooms and farmed corn, beans and squash, living there from the late 1270s to about 1300.4
• The Gila Wilderness that surrounds the monument is considered homeland by the Chiricahua Apache people today, according to the National Park Service.4
• The Gila and Mimbres valleys are part of New Mexico's roughly 700-acequia system, and acequias including the Grijalva Ditch were damaged by post-fire flooding following the 2022 Black Fire, according to the New Mexico Acequia Association.5

Habitat

• The Gila's riparian gallery woodland and its high concentration of breeding birds provide habitat for the federally threatened loach minnow and spikedace and the endangered southwestern willow flycatcher.3
• The forested canyons of the Gila Wilderness support the world's largest population of the rare Mexican spotted owl, along with wild turkeys, elk and cougars.2
• The spikedace and loach minnow, small fish listed as threatened in 1986 after habitat loss and non-native fish introductions, depend on perennial riffles of sand, gravel and rubble; their federally designated critical habitat covers stretches of the Gila and San Francisco rivers in Catron, Grant and Hidalgo counties.6
• Gila trout, a rare and endemic fish, were listed as federally endangered in 1973 and under New Mexico law in 1974; decades of conservation and restocking work, now guided by the 2022 Revised Recovery Plan for Gila Trout, have allowed the species to be downlisted to threatened, though wildfire remains a major threat to populations such as those in Whitewater and Willow creeks.7

Reservoirs

From the archive: National Inventory of Dams (USACE) and the reservoir registry.

Water users

• Silver City and the small community of Cliff, about 28 miles away via US 180, anchor human use of the upper river; The Nature Conservancy's Gila River Preserve near Silver City has enrolled water rights in an upper Gila ditch conservation plan to help keep water flowing in the river during low-flow periods.3
• Under the 2004 Arizona Water Settlements Act, New Mexico held rights to develop up to 14,000 additional acre-feet a year from the Gila, and in November 2014 the state's Interstate Stream Commission voted to move forward with a diversion and storage project on the upper river, with one commissioner dissenting over its cost.8
• That diversion project stalled: after New Mexico failed to complete required environmental studies and secure a Record of Decision, the Interior Department in December 2019 denied a deadline extension, cutting off up to $56 million in construction funding under the Arizona Water Settlements Act, while the state's CAP entity retained about $70 million in the settlement fund for other regional water projects.9

Surface water withdrawn, 2020

In the counties this river crosses (Grant, Hidalgo): 38,860 acre-feet. County totals include other streams.

State Engineer, New Mexico Water Use by Categories 2020.

Public water systems beside the river

Virden Water System, Gila Mesa Association

State Engineer's public water systems layer (service areas within 2 km).