Signup for our emails
Ditch rehabilitation needs to ensure passage for native fish
DENVER—WildEarth Guardians called on the Colorado Water Conservation Board today to carefully scrutinize a proposed ditch and headgate rehabilitation project on the Rio Grande in Colorado before the Board approves the funding to ensure that aquatic and riparian habitat of the river is improved, not compromised. The group’s request came in the form of a letter of concern submitted to the Board to be considered at today’s meeting in Ward, Colo.
The Colorado Rio Grande Restoration Foundation’s proposed Five Ditches Project includes the removal and replacement of old diversion structures at the Rio Grande #2, Consolidated and Pace Ditches, San Luis Valley Canal Headgate, and Centennial Ditch to improve diversion efficiencies. The project, however, is defined more broadly to include bank stabilization, riparian plantings and other onsite restoration of the stream channel to enhance water quality, improve riparian and wetland condition, increase sediment transport, improve aquatic and riparian habitat, encourage local recreation, and promote public involvement.
“This project is not inherently bad, but the devil is in the details,” said Jen Pelz, Wild Rivers Program Director for WildEarth Guardians. “We appreciate the Foundation incorporating restoration goals into this project, but intend to hold them accountable for meeting these commitments—not just paying lip service to the named environmental objectives.”
One of Guardians’ concerns is with the preliminary design for the Consolidated and Pace Ditch diversion. The proposal involves removing the existing relatively natural rock dam that currently allows both fish and boat passage and replacing it with a concrete structure that will span from bank to bank. Fish and boat passage are planned mitigation for the new dam structure, but the designed concrete fish ladder does not provide bidirectional passage for non-game native fish.
“The lack of passage for native fish is unacceptable,” added Pelz. “Segmenting river habitat for already imperiled species does not meet the goal of improving aquatic and riparian habitat. We hope that the Board and/or the Foundation will reconsider its preliminary designs to meet their commitments to the river and its native species.”
The Five Ditches Project is the second round of such diversion reconstruction projects along the Rio Grande near Monte Vista. The Board approved and construction is nearly complete at the McDonald and Prairie Ditches. Guardians became involved in the McDonald Ditch Project out of concern that the restoration efforts of removing the dam could endanger a recently discovered population of Rio Grande chub found adjacent to the project site.
The Rio Grande’s namesake chub has not been sighted on the main stem of the river in more than 50 years. In 2013, based on the status of the species and the continuing threats to its survival, Guardians submitted a scientific petition to the U.S. Fish and Wildlife Service requesting listing of the Rio Grande chub under the Endangered Species Act. On March 16, 2016, the Service found that the petition contained “substantial information” indicating that listing may be warranted. Currently, the Rio Grande chub is still working its way through the process of obtaining the full protections of the Act.