Description of the Project

The Elkhorn/Las Delicias Watershed Restoration Demonstration Project (Elk/LD Demo Project) showcases planning, installation, and monitoring of watershed restoration practices in ephemeral arroyos and associated uplands and tributaries in a flash flood dominated landscape of the Altar Valley. This project tells the story of collaborative conservation in action, throughout each phase of planning, installation, monitoring and evaluation.

A generous grant of $50,000 from Freeport-McMoRan Copper and Gold Foundation provided the base for funding the project.  Match contributions and the donation of time and energy from partners brought the total invested in the project to over $200,000.  The Alliance has since received grants annually from Freeport-McMoRan to continue maintenance, monitoring, and conduct educational activities at the site.

The approximately 1500-acre project site, located on Arizona State School Trust Land, bridges two neighboring ranches. A poorly drained fence-line access road bisected 25 drainage channels, many of which had become deeply incised, with increasingly severe erosion creeping and branching upstream. A team of restoration experts evaluated the site and designed a treatment plan in April 2011 based on landowner objectives and the principles and practices described in Bill Zeedyk and Van Clothier’s watershed restoration primer Let the Water Do the Work and Bill Zeedyk’s book A Good Road Lies Easy on the Land: Water Harvesting from Low Standard Rural Roads.

In January 2012, the planning team, armed with rock, machinery and volunteers, reconvened to install the project. All told, the project team staged and planted 920 tons of rock by hand and/or with machines, and then used the rock to install 359 structures in six of the 24 channels. A 7th channel was treated with mesquite harvested on site. The 3.25 mile stretch of road was treated with 54 rolling dips and 14 road crossing stabilization structures, with associated one rock and media luna structures.

The project team designed a monitoring program and collected base-line monitoring data during and immediately following construction, before any precipitation occurred in the project area. During the two years following the installation of the project, the monitoring of treated and untreated channels included extensive field evaluation, photo monitoring, vegetation and substrate transects in stream channels, survey of stream channels’ longitudinal profiles and cross sections, mapping, and rainfall. In January 2014, the project team reviewed monitoring data, conducted a thorough field evaluation, convened a one-day public workshop attended by a diverse group of 25 people to evaluate the project, and worked together to compile the final project report.

Monitoring and evaluation findings as of January 2014, after only two years and three rainy seasons (2 monsoon and 1 winter) indicate:
• Increased soil deposition in channels and associated tributaries and uplands;
• Minimal vegetation change to date within, but vegetation increase is expected as soil deposition continues;
• Increased vegetation diversity and density evident in upland rock structures and road treatment sites;
• Impressive sediment and vegetation response to wood treatment in alluvial fan;
• Excellent structural integrity of all treatments, with very few repair needs;
• Minimal to no evidence of construction impacts, with the exception of rock left on site for continued work;
• Monitoring techniques are repeatable, useful and statistically valid;
• Project success can be enhanced by augmenting existing and/or adding additional rock or wood structures; and
• Significant learning and research opportunities are available due to excellent access, monitoring data, and broad support for the project.

The project team is generally optimistic that the stage has been set for healing to continue over time via the natural processes of erosion and deposition that occur in river systems; and that the site is fulfilling its promise as a demonstration and learning site. Since project planning began in 2011, hundreds of people have visited the project site and/or followed its progress via Altar Valley Conservation Alliance communication and education activities. The Altar Valley Conservation Alliance produced several videos and used social media to document and share the demonstration project. AVCA is delighted that the University of Arizona Society student chapter of the Society for Range Management, Tierra Seca, has become a partner in project monitoring.  The Altar Valley Conservation Alliance and its partners anticipate that the Elkhorn/Las Delicias Demonstration Project will continue to serve a vital role in supporting the teaching and understanding of the low-tech erosion control techniques employed at the project site.

The Elk/LD Demo Project models best-management practices and serves as a field classroom for public education. Furthermore, a scientific monitoring program evaluates results to inform maintenance & design of future projects.

Don’t forget to check out our web guide for the project!

Additionally, we now have a GIS Map Portal for the Elkhorn/Las Delicias Demonstration Project Site. It can be found on our GIS Portal.