Restoring Agricultural Valley River Health in New Mexico

By Dr. Connie Maxwell, Research Scientist, NM WRRI, & Dr. Sam Fernald, Director, NM WRRI and Professor of Watershed Management

NM WRRI was awarded and has kicked off a New Mexico Environment Department River Stewardship project entitled “Improving Watershed Hydrologic Function to Restore Health of River Ecosystems alongside Farming and Rangeland Communities of the Rio Grande Basin in New Mexico.” The outcomes that address the River Stewardship Program are the resulting increase in surface water quality and river health from addressing the root of the issues. The project received the notice to proceed on May 23, 2023, and is expected to be completed by June 30, 2025.

The project includes three locations across the Rio Grande river continuum, from the headwaters to the middle and Lower Rio Grande, and from the forests to the desert, which all have varying river characteristics, ecoregions, and vegetative cover, as well as different communities. Canjilon Creek is a forested headwater system of the Rio Chama, which is a tributary to the Rio Grande; El Guique and Estaca are communities in the river valley of the Rio Grande in northern New Mexico; and the Placitas Arroyo watershed is a relatively large watershed that flows into southern New Mexico Rio Grande valley. Like most agricultural river valley systems throughout New Mexico and the Southwest, all sites also share similar underlying challenges of increasing runoff, erosion, and pollutant delivery.

Communities are severely impacted by the root causes of the issues that are degrading the Rio Grande and its tributaries, thus our team employs both a community-based and watershed-based approach. The locations were identified by community members as having critical issues that reflect typical challenges for the regions. The two northern New Mexico locations were chosen with support from New Mexico Acequia Association and NM WRRI’s initiative Building Agriculture and Water Resilience, and the southern New Mexico location, with help from the South Central New Mexico Stormwater Management Coalition during a regional watershed planning effort. A watershed-based approach is also critical, as the effects of climate change and drought on surface water quality and river health begin at the upper headwaters. As many in New Mexico, and across the Southwest, are experiencing, climate change has already begun to have significant impacts. Water cycle intensification of dry and wet periods and aridification from warming temperatures and the resulting increased evaporative demand are driving a key suite of processes impairing river water quality and stream habitat. Reduced vegetative land cover and infiltration coupled with more extreme rainfall events are causing increased flooding, erosion, and sediment delivery to river ecosystems.

The goal of this project is to counter water cycle intensification by reducing flooding and sediment yield through the implementation of watershed management practices. The project objectives are 1) Increase surface water quality, and 2) Increase watershed and riparian functions of spreading and filtering flows. Practices will be implemented that increase vegetative cover, increase floodplain inundation, delay surface runoff, increase infiltration, reduce erosion, and reduce delivery of sediment and other contaminants to the receiving river.

The forested headwater location, Canjilon Creek, is a 24-mile stream in the Carson National Forest of New Mexico that flows into the Rio Chama. Canjilon farmers typically get two irrigation distributions a season. Recently, often only one has been available. Upper watershed river systems optimally function as sponges that store water in their floodplains across the full valley. As temperatures and storm intensities increase, erosion disconnects channel flows from their adjacent floodplains, floodplains begin to dry out and cloud the flows with silt, water temperatures rise, and native cut-throat trout struggle. As increase. This work aims to restore the natural functions of the river system to provide optimal water storage within the riparian corridor as described by Norman Vigil, Upper Chama Soil and Water Conservation District chairman as well as a local farmer. Using approaches that mimic beaver activity by slowing and infiltrating flows into floodplains, the local stakeholders’ goal is to build up the base flow and extend the flow to July and restore the fisheries. The team for this location includes the Upper Chama Soil and Water Conservation District (UCSWCD); NMSU’s Cooperative Extension Service Extension Agricultural Agent; Keystone Restoration Ecology, Inc. (KRE), Trout Unlimited, Inc., and as a collaborator, the Chama Peak Alliance.

In the El Guique and Estaca communities in the river valley of the Rio Grande in northern New Mexico, large rainfall events that hit the Black Mesa and the high gradients along its face have historically caused downstream flooding and cross drainage problems to the river channel. Despite several dams in the area, high energy floods still pass through the asphalt and aggregate mine, Espanola Transit Mix, Inc. frequently overwhelm the agricultural community downstream. A berm prevents flood flows from the arroyos entering the Rio Grande with few areas of connection, which is a frequent issue along the Rio Grande. The project starts with practices that slow and spread flows at the source, atop the Black Mesa and down through the uplands. At a significant confluence in the valley below, the team will spread the flow to drop out sediment and debris and create a new connection through the berm. At two riparian areas, the team will also remove invasive species to reduce competition to the extensive native species present. The team for this location includes the Upper Chama Watershed District; Española Mercantile Company; Private Landowners; East Rio Arriba Soil and Water Conservation District; Mesa Prieta Petroglyph Project; Keystone Restoration Ecology, Inc.; Ancestral Lands Conservation Corps; and Natural Channel Design.

The Village of Hatch is directly downstream from the Placitas Arroyo watershed which flows into the southern New Mexico Rio Grande. Hatch experienced a significant flood in 2006, and one of the major sources of flooding was the Placitas Arroyo. The Rio Grande receives significant sediment deposits into its channels from flood flow events from this and other watersheds throughout the region. Local stakeholders have been considering emergency measures to address scouring watershed flows for years. This work will help restore the natural functions of the arroyo headwaters to the river system to slow, spread, and filter flows of sediments, nutrients, and contaminants. The community then additionally benefits from reduced flooding risk and increased watershed health. The team for this location includes the State Land Office; the Caballo Soil and Water Conservation District (CSWCD); and High Desert Native Plants.