Dried Up Delta

In this post, I will explore issues surrounding the Colorado River Delta, noting why the delta is of importance, and how today these issues are being addressed in order to ensure a sustainable future for the ecosystems involved.

Dried up Colorado River Delta
Photo courtesy of davidmfrey.com

Before the development of the Colorado River, the river wound its way, untamed to the Gulf of California in Mexico.  The Colorado River Delta once extended over most of the Salton Trough, pictured below, but due to the high demand of the river’s water, today the delta has been depleted. 

Salton Trough
Photo courtesy of wikipedia.org

A Look Into the Delta’s Past and Current State

The Colorado River Delta was once a thriving and dynamic environmental system home to freshwater, brackish, and saltwater species.  This unique combination of habitats was due to the interaction between the ocean’s tide and the Colorado River’s flows. The historic delta was comprised of over 2.5 million acres of wetlands and provided habitat for an estimated 400 species of plants and wildlife. Once the river reached the delta, it broke off into multiple small channels covering the entire Salton Trough, creating an extensive wetland. Below is a picture of what the Colorado River Delta once looked like when the Colorado River waters reached the Gulf of California.  

 

Healthy Colorado River Delta
Photo courtesy of www.geo.arizona.edu

At one point in time, before the construction of various dams along the river, significant quantities of nutrient-rich silt were carried down the Colorado River to the delta.  Today, with the exception of a few unusually wet years, the Colorado River Delta looks like a barren desert.  Pictured below is an image of the delta taken on September 8, 2000 by the Spaceborne Thermal Emission and Reflection Radiometer flying aboard the Terra spacecraft.

Photo courtesy of earthobservatory.nasa.gov

In this image, the Colorado River is the dark blue line at the top left and weaves its way through the multicolored farmlands in the northwestern corner, finally reaching its end at the base of the Sierra de Juarez Mountains.  It is clearly noticeable in this image that a good amount of the Colorado River water is pulled out for irrigation of farmlands. “Roughly 10 percent of all the water that flows into the Colorado River makes it into Mexico and most of that water is used by the Mexican people for farming.” 

“The bluish purple river that appears to be flowing from the Gulf of California to the north is actually an inlet that formed in the bed of the Colorado River after it receded.” All of the gray areas surrounding the inlet are mud flats created over the last millions of years, before the construction of dams, by sediment carried down from the river. Lastly, the yellow expanse to the east of the farmlands is the Gran Desirto and the bluish-green patch located between the farmlands and the desert is known as the Sienega de Santa Clara. The Sienega de Santa Clara is a salt-water marsh home to many bird populations, including the endangered species, Yuma Clapper Rail and the Southwestern Willow Flycatcher. 

Below, two images of this region are pictured showing the great recession of the Colorado River Delta over time. The image on the left, from 1985, shows flows from a relatively wet year while the image on the right, from 2007, shows the current state of the delta with limited flows to this region.

Two photos of the Colorado River Delta. Left image taken in 1985 in a record high flow year while the image on the right, taken in 2007 was in a record low flow year.
Photo courtesy of coastalcare.org

Delta Recovery Efforts

The recovery of the Colorado River delta is of great importance in sustaining the future of the river and thus, many new efforts to improve the delta’s condition have been made.  In particular, Minute 319, a landmark agreement made between the U.S. and Mexico that “defines how the two countries will share Colorado River water amidst growing pressures on water resources” was passed. The key features of Minute 319 are the environmental component to bring water back to the Colorado River in Mexico and to expand restoration efforts in the delta.

Photo courtesy of www.sonoraninstitute.org

Prior to the agreement of Minute 319, the Colorado River Delta Water Trust was created in order to “acquire and lease water for environmental purposes.” Once Minute 319 was passed, the Colorado River Delta Water Trust was to “secure one-third of the total flows that will be allocated to the Colorado River, while Mexico and the U.S. will contribute the remaining two-thirds of the flows.” In regards to expanding the restoration efforts, the agreement requires the NGO coalition to widen restoration efforts in the Delta.

Currently this coalition is partnering with the Nature Conservancy, National Fish and Wildlife Foundation, and the Redford Center along with various governmental organizations in a project called “Raise the River.” The goals of Raise the River are to,

• Secure a base flow for the river
• Temporarily reconnect the Colorado River with the sea
• Enhance 2,300 acres of habitat by 2017

By accomplishing these goals, Raise the River will establish a framework for the long-term dedication of water to the Colorado River Delta.

In my next and final post, I will discuss the outlook on the future of the Colorado River. With much uncertainty surrounding this issue, there is one thing that is for certain, something must be done to protect the Colorado River from drying up if it is to continue flowing for the centuries to come.