Untitled DocumentGroundwater flow dynamics in the Colorado River Delta
Macro Theme Area:
Knowledge Transfer [Project ID: K60]
PI:
Juan Valdes
CO-PI(s):
Juan Valdes
Basin focus:
Colorado
Specific area in
basin /
field sites:
Colorado River Delta, Republic of Mexico
Summary/Goals: Quantification of groundwater flow dynamics and of the interactions among groundwater, surface water, and riparian vegetation, represent key components in the development of a balanced restoration plan for functional riparian ecosystems. The goal of this research is development of a groundwater model, using MODFLOW 2000, in support of riparian restoration along the Colorado River Delta (Mexico: Baja California, Sonora). The Colorado River is widely recognized as one of the most modified and allocated rivers in the United States. For over 50 years flows into the Delta were severely reduced by the requirements of an emergent American West. However, subsequent to discharge pulses associated with the filling of Lake Powell, and the increased precipitation that accompanied ENSO cycles, a semblance of a native riparian habitat has been observed in the Delta since the 1980's (Zamora-Arroyo et al. 2001). The Delta and the riparian ecosystems of the region have since become the focus of a substantial body of multidisciplinary research. Our research goal is understanding water table dynamics with particular attention to stream-aquifer interactions and groundwater behavior in the root zone. The project aims to quantify groundwater reliant transpiration requirements for a set of dominant native riparian species using the Riparian ET (RIP-ET) package, an improved MODFLOW evapotranspiration (ET) module. RIP-ET simulates ET using a set of eco-physiologically based curves that more accurately represents individual plant species, reflects habitat complexity, and deals spatially with plant and water table distribution. When used in conjunction with a GIS based postprocessor, RIP-ET provides the basis for mapping groundwater conditions as they relate to user-specified plant groups. This explicit link between groundwater and plant sustainability is a driver to restoration design and allows for scenario modeling of various hydrologic conditions. In this project we specify locations in the Delta where riparian restoration has the maximum chances of success without artificial irrigation. Groundwater requirements determined in this research will be used by the international non-profit organizations, The Sonoran Institute and Environmental Defense, to implement large-scale planting activities within the riparian corridor and to secure instream flow rights for the Colorado River Delta from the Mexican Government.
Activities and outcomes during past year:
This project is now funded in part by Ties Grant.
Plans for the upcoming year:
MODFLOW model will be completed and delivered to the Sonoran Institute.
Organization Involvement:
The Sonoran Institute has comissioned the Colorado River Delta groundwater model as a tool they will employ in their environmental work within the region.
