Riparian Planting Projects
Navajos believe that Torreon Wash is their lifeline. The cottonwoods and willows that used to grow along the Wash, were, according to older Navajos, holding the culture together. We have been trying to help residents of Eastern Navajo restore this lifeline to Navajo culture by planting native cottonwoods and willows along the Wash and its tributaries.
We began working on riparian plantings under the Targeted Watershed Grant RPA received from the EPA in 2007. With additional funding from the State of New Mexico and the BLM, we planted over 3,000 cottonwoods, innumerable willows, and at least 1,000 other riparian shrubs in selected areas of Torreon Wash, Penistaja Arroyo, and San Isidro Wash, largely through the efforts of volunteers from the community, the schools (3rd through 6th grade children), and the Sierra Club.
But, there are many other areas of the Wash and its tributaries that also need work. This year, community members from Ojo Encino have been planting again with funding from the National Fish and Wildlife Foundation.
The geographic area we have been focusing on is the Torreon Wash area of the Arroyo Chico drainage of the Rio Puerco. This area has the lowest level of vegetative cover, with riparian vegetation almost non-existent, and the highest level of bare ground and erosion in the Rio Puerco Watershed. Both Torreon Wash and the Arroyo Chico are ephemeral to semi-ephemeral streams, flowing in response to spring snowmelt and summer storms. Riparian areas are related to and dependent on their adjacent waterways, such as the Arroyo Chico and Torreon Wash and its tributaries, because the presence of water for all or part of the growing season determines their extent and vigor. Vegetation along the waterways is almost exclusively upland shrubs and grass species such as rabbitbrush and sacaton, except in those areas that receive surface runoff when the channels flow. There, sedge, willows, and cottonwoods grow.
The Rio Puerco watershed is the primary source of undesirable fine sediment that is annually delivered to the Rio Grande system. According to the U.S. Geological Survey (USGS): “. . . the Rio Puerco basin. . .transports one of the world’s highest average annual sediment concentrations. . . . The largest contributor of suspended-sediment load in the Rio Puerco basin is the Arroyo Chico, which drains 24% of the basin and delivers 34% of the suspended-sediment load.” The Corps of Engineers has noted that soil erosion within the watershed surpasses that of any other watershed in the country, yielding 1.36 acre-feet per square mile per year. The establishment of proper native species will contribute to keeping soils, banks, and floodplains in place and functioning properly.
Our ecological objectives have been to have:
measurable increases in wetland vegetation;
measurable increases in moist soil;
measurable increases in sinuosity in the steam channel; and
measurable decreases in eroding banks.
This portion of the Rio Puerco watershed is intermittent, running (sometimes heavily) during snowmelt and monsoons. However, ground water remains close to the surface even during drought periods and supports riparian vegetation. In our plantings, we have almost always hit water with the auger and have been able to place the ends of the cottonwood poles in holes with standing water. Generally, we have had at least a 65-75% success rate.
Native willow and cottonwood regeneration to stabilize drainage channels in Torreon Wash can be hampered by uncontrolled grazing. Plants often are eaten by cattle, horses, and sheep before they can become established, so fencing is essential. We have fenced all of our planting sites.
Agriculture is the dominant watershed-wide activity, but a substantial portion of the rural population is concerned about its ability to maintain a traditional lifestyle with a natural resource-based economy. Erosion carries away the region’s most productive topsoil and reduces the land’s already limited ability to absorb water.
That ability is being further affected by unpredictable changing climate conditions. It is essential to restore riparian vegetation to the area to reduce erosion, minimize invasives, and re-establish sinuosity. Our work can be a win-win-win strategy for addressing the changing climate, rural poverty, and water scarcity.
We have had some of our partnerships in Eastern Navajo for over 10 years. Through our combined efforts we have begun to seriously impact the area, and we have helped many children and their parents learn about the need for riparian vegetation. We would like to continue this effort into the future.