|dc.description.abstract||Much of the Middle Rio Grande has severely degraded since 1930 when flood control institution began (Scurlock 1998). Since that time, additional anthropogenic stressors have continued to cause the river to incise and narrow and have harmed the ecological health of the system. As a result, many different entities have developed restoration projects along the Middle Rio Grande. These projects are often localized, small scale features that promote native vegetation establishment and improve habitat for endangered species without removing flood protection measures.
One such feature is the Rio Grande Nature Center (RGNC) Habitat Restoration project. The project consists of removing non-native plants and constructing an ephemeral, high-flow, side channel connected to the Rio Grande in Albuquerque, New Mexico. The channel provides habitat for the Rio Grande Silvery Minnow and helps connect the river to its floodplain, promoting establishment of native vegetation.
Since its completion in February 2008, the RGNC side channel has provided improved conditions for native vegetation and silvery minnow but has undergone significant aggradation. This deposition brings into question the sustainability of this project. One- and two-dimensional numerical models are developed to model the RGNC channel, determine project life-cycle, examine modeling approaches, and alternative designs.
One-dimensional modeling efforts were determined to be insufficient for capturing the sediment transport measured in the RGNC channel. Two-dimensional modeling results proved to be sufficient, indicating that this level of modeling can be applied as a useful design tool. Two-dimensional modeling suggests a project life of up to 50 years with the channel reaching a dynamic equilibrium after 15 to 20 years. Though the channel should last for 50 years, the duration and magnitudes of flows will likely be reduced. Alternative designs were modeled. These models suggest that embayments (described herein) are an effective, sustainable feature in high-flow, side channel restoration projects. However, the alternative designs suggest that the use of adverse slopes at the upstream of side channel restoration designs will contribute to a reduced project life.||en_US