Gallinas River

About the Gallinas River

• The Gallinas River rises in the Sangre de Cristo Mountains and is one of the most important tributaries of the Pecos River; it is the primary source of drinking water for the City of Las Vegas, New Mexico.1
• The 2022 Hermit's Peak/Calf Canyon Fire, which began as U.S. Forest Service prescribed burns and became the largest wildfire in New Mexico history, devastated San Miguel and Mora counties.2
• The fire burned about 341,735 acres and scorched the Gallinas River's upper watershed, and the ash and sediment that followed overwhelmed Las Vegas's water treatment plant.3

This report follows 90 miles (146 km) of the Gallinas River, all within the Pecos Headwaters watershed segment. At the lower end of the report the river drains about 633 square miles. Downstream of the mapped reach it flows into the Pecos River. Named tributaries joining it here include the Arroyo Pecos, Rito Vegoso, Aguilar Creek, Agua Zarca and Alamito Creek. Largest urban areas near it: Las Vegas. 4 gauges with at least 26 weeks of daily flow cover 1904 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: Pecos Headwaters

   87 cfs last week much above normal, 100 dry days this year.

   Towns: Las Vegas.

   Water 8.7 °C at Gallinas Creek Near Montezuma, NM. Median conductance 242 µS/cm in the 2020s. Rain over the last 3 months: 167% of normal.

Culture

• The Rio Gallinas Acequia Association and the Placita de Arriba Acequia Association are among the acequia groups active in the watershed, and together with the Las Vegas Land Grant and San Miguel County have taken part in Gallinas River watershed planning.1
• Acequia elected officials and parciantes (member irrigators) govern their community ditches as local institutions of government, and the New Mexico Acequia Association provides governance assistance and advocacy to acequias statewide.4

Habitat

• The Gallinas watershed ranges from about 4,900 to 11,600 feet in elevation and supports piñon-juniper and ponderosa pine at lower elevations, oak brush and mountain mahogany on drier slopes, mixed conifer at mid-elevations, and a spruce-fir zone above roughly 9,000 feet, with the Forest Service managing more than half of the upper watershed to help protect this cold-water fishery.1
• The 2022 fire and the post-fire flooding that followed struck the Gallinas Canyon stretch of the river; Forest Service recovery work across the burned area has since included more than 21,000 acres of erosion-control seeding and over 1,200 acres of erosion-control mulching aimed at stabilizing the watershed and protecting the river corridor.5
• Following the fire, even moderate monsoon storms sent high-ash, sediment-laden flows down the Gallinas - measured at roughly 1,800 cubic feet per second at the Storrie Lake diversion in one event - raising fears the water would become too degraded to treat.6

Reservoirs

No reservoir with 500 acre-feet or more of storage on this river in the National Inventory of Dams.

Water users

• The Gallinas River is the primary source of drinking water for the City of Las Vegas, and its watershed supplies drinking water to roughly 20,000 people altogether.1
• The City of Las Vegas holds Gallinas River water rights of 1,200 acre-feet per year with an 1835 priority date and 2,400 acre-feet per year with an 1888 priority date, plus off-stream storage permits for Peterson Dam and Bradner Dam.6
• After the 2022 fire, ash and sediment overwhelmed the city's water treatment plant, and by late August 2022 Las Vegas had only about 21 days of water left in storage; the city is now planning a roughly $140 million overhaul with a new treatment plant, pre-treatment sediment removal, and wastewater-reuse capability, described as its largest capital project ever.3
• The Hermit's Peak/Calf Canyon Fire Assistance Act established a FEMA Claims Office, with locations in Santa Fe, Las Vegas and Mora, to compensate people for losses from the fire and the flooding that followed it.7

Surface water withdrawn, 2020

In the counties this river crosses (Guadalupe, San Miguel): 102,965 acre-feet. County totals include other streams.

State Engineer, New Mexico Water Use by Categories 2020.

Public water systems beside the river

City of Las Vegas

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