In just two years following a man-made flood in the Colorado River Delta, cottonwoods and willows have grown 10 feet tall, rebuilding habitat for other native plants and animals, according to a new monitoring report on the international experiment to re-water the long-arched region.
New growth in delta could offset CO2 released from riverbed
Human management of natural ecosystems always has unintended consequences, and the Colorado River is no exception. After decades of intense dam building and diversions, the mighty river is a mere shadow of it former self, reduced to a trickle in some places and polluted by return flows in others. Along its entire length, ecosystems, including riparian zones and native fish, have suffered, with some of the biggest impacts in the Colorado River delta.
In an effort to restore at least some key reaches of the river, scientists and water managers have teamed up to try mimic some of the Colorado’s natural functions, with controlled releases of water to build up beaches. Those efforts culminated in early 2014 during an eight-week experiment that unleashed a mighty torrent of water from Morelos dam (on the border with Mexico and the USA).
The huge surge (130 million cubic metres) of water raised river levels down to the delta, which has been starved of water for decades. Scientists closely monitored how the release — and potential future releases — affect agricultural crops and natural plant and animal life of the lower delta.
Science team tracks effects of historic pulse flow
FRISCO — Last May’s pulse flow in the Colorado River helped revive vegetation along a huge swath of the river’s edge, triggering new plant growth and raising the water table in the delta. After comparing satellite images taken August 2013 with new images from this year, scientists calculated a 23 percent increase in the greenness of riparian zone vegetation. Continue reading “The ‘greening’ of the Colorado River Delta”→