Albuquerque Overbank Project Celebrates 10th Anniversary
What would happen if Reclamation cleared a point bar along the Rio Grande, lowered banklines to reconnect the river to the floodplain and just let nature take its course? That was the question posed by Reclamation Environmental Protection Specialist Nancy Umbreit and Dr. Cliff Crawford of the University of New Mexico back in 1997. They agreed to get key parties together to discuss the possibilities.
“Functional restoration of the largely levee bounded bosque had received much attention but little implementation,” Crawford said in a paper on the project. “The Albuquerque Overbank Project initiated in early spring 1998 was the first project of its type within the Middle Rio Grande valley.” Overbank flooding is a natural process that once occurred frequently on the Rio Grande.
The Albuquerque Overbank Project located between Bridge and Rio Bravo on the Rio Grande's west bankline, was undertaken as a partnership between the Bureau of Reclamation, Albuquerque Open Space, the Middle Rio Grande Conservancy District, the Fish and Wildlife Service, Natural Heritage New Mexico of the University of New Mexico’s Biology Department and the Army Corps of Engineers.
The group created a plan for the project to reconnect the Rio Grande to the flood plain by lowering the bank line approximately two feet, removing about four acres of nonnative Russian olive from the site, and creating a side channel. Restoring the river-food plain connection would allow natural flooding from spring runoff to facilitate natural reestablishment of native vegetation and variable habitat which is beneficial to numerous fish including the endangered Rio Grande silvery minnow.
The results of this low cost project were better than anyone could have imagined; more plant diversification, species richness, a wider river channel, a side channel. Greater habitat variability could be seen as more than 8,000 cottonwood seedlings, a smaller number of willows, Russian olives and saltcedars were established during the first flood season. Although most of the cottonwoods died before the second season, several thousand survived. “The key was to take advantage of the right conditions and allow the river and nature to do the work,” Umbreit said of the area which is now a patchwork of willows and cottonwood trees, grassy meadows, sedges, cattails and wildflowers. “There’s a lot more diversity when mother nature does the job of replanting.”
At the beginning of the project, 18 groundwater monitoring wells were also established throughout the site to monitor the interrelationship of the river and groundwater and the effects of drought on deep rooted vegetation at the site. Vegetation on the site was initially monitored every year for five years by Natural Heritage New Mexico. Monitoring has now been reduced to every five years. The new information is expected to come out in late June. All vegetation monitoring is being done under the direction of Dr. Esteban Muldavin of Natural Heritage New Mexico.
To mark the 10th anniversary, the agencies involved in the original project and New Mexico State Parks have teamed up for a series of lectures and tours of the project area. The first lecture featured Crawford and took place in April. A walking tour of the project is scheduled for July 20, followed by another tour and lecture planned for September.