Conservation and restoration projects seek to restore habitats and
balance human needs for water with the needs of native plant, wildlife and marine species
In Colorado River Story – Part 1, I wrote about the dams built from 1908 to 1968 to harness the water and power of the river. Although the dams provide power and water to millions of people, irrigate hundreds of thousands of acres of farmland, control flooding and create recreational spaces, they have also created unintended consequences. The Colorado River no longer runs to the Gulf of California, but instead dries up before the U.S/Mexico border. Wetlands have disappeared. Colder water temperatures, lake environments, reduced sediment and lack of seasonal flooding have had negative impact on native species. Non-native tamarisk, also known as saltcedar, thrives in many of the depleted environments and quickly dominates.
With the human need for water in the area increasing and levels in the Colorado River declining, the situation appears bleak, but I found encouraging signs when I learned about some of the restoration and conservation projects underway in the lower Colorado area.
The Yuma Wetlands Project (YEW) is pioneered by the Quechan Indian Tribe and the city of Yuma. The YEW project developed innovative clearing, irrigation and planting techniques on 1,418 acres of riparian, wetland and aquatic habitats. The recovering bird population is emblematic of the success of the project.
The Lower Colorado River Multi-Species Conservation Program seeks to balance human use of water with the needs of native species and their habitat. Conservation activities benefit 31 species of endangered or sensitive fish, wildlife and plants. During its 50 year duration , the program will create over 8,100 acres of habitat, stock over 1.2 million native fish and monitor 400 miles of river extending from Lake Mead to the U.S./Mexico border.
In 2012, the U.S. and Mexico signed a five-year agreement to address issues in the Colorado River Delta related to bi-lateral water management during periods of drought and historic losses of water flow. “Minute 319” includes elements for enhancing water infrastructure, conservation, water sharing and promoting the health of the river delta. The Colorado River Delta Restoration Project aims to create almost 9,000 acres of ecologically functional demonstration sites of healthy terrestrial and aquatic habitat by 2017.
I became intrigued with this project after reading about it in the newspaper. When I learned that Dr. Francisco Zamora Arroyo, director of the project, was giving a lecture at a Mesa, Arizona public library, sponsored by the Desert Rivers Audubon Society and the AZ Sci-tech Festival, I welcomed the opportunity to attend and learn more about the project.
The project targets the riparian corridor between Yuma and the U.S./Mexico border, with the restoration site in the Laguna Grande area. Restoration is done by creating conditions for natural germination. An active restoration approach involves planting mature trees and irrigation. A passive approach involves getting water back into the area and letting nature take its course. Dr. Zamora said they discovered a need for a hybrid approach, an assisted approach in which non-native species are removed, grading is done to open river channels, and seeds are collected and spread in some areas.
All approaches require getting water back into the area. This is done with controlled flows from the dams. Two types of flow are part of Minute 319. Base flows are small amounts released continuously through the term of the agreement. A one-time pulse flow, during March and April of 2014, released a larger surge of water over an 8-week period, with the majority concentrated within 4 weeks. The pulse flow was meant to mimic the annual spring flooding that used to occur. As a result of that pulse, water flow reached further than expected, to open estuaries from the the Gulf of California, also known as the Sea of Cortez. The flow was temporary, but exciting and provided signs of comeback.
In many ways, the restoration project is a research effort, with scientists studying and recording impacts and outcomes. They’ve learned that native plants have a higher establishment rate when non-native vegetation is cleared out. Base flows have been reduced in summer as per a natural cycle.
Results to date are promising. In some areas, cottonwoods and willows have grown within a few months. There has been an increase in bird populations.
The Minute 319 agreement ends in 2017. In his lecture, Dr. Zamora mentioned the need for a new agreement, but his overall message was one of hope. He ended the lecture with a 10 minute video about the experience of the river coming alive again after the pulse flow. The film is narrated by Robert Redford. The scenes of families in San Luis Rio Colorado, Mexico playing and laughing in the river flowing by their town, a sight many had never seen, can’t help but make you smile. I invite you to watch the film here.
Several organizations are funding and supporting projects to save the Colorado River and restore habitats. Save the Colorado and Raise the River are two such initiatives. I wonder how the story of the Colorado River will unfold over the next decades and what part 3 of the story will bring.
(Information sources: displays at Yuma Quartermaster Depot State Historic Park, February 2015 lecture by Dr. Francisco Zamora Arroyo, Sonoran Institute)