Evaluation of Channel Re-Alignment Alternatives on Shallow Groundwater and Wetlands
As part of a feasibility study relating to channel alignment along the Rio Grande, SSP&A fine-tuned and applied a high-resolution riparian groundwater model to characterize alternative groundwater and wetland conditions under a range of seasonal and flow conditions. For this project, SSP&A drilled and monitored wells along river transects, monitored river and drain stage; then, incorporated the site-specific data into the model, including LiDAR land surface elevations and high-resolution vegetation coverages. SSP&A prepared a series of flow-dependent River Packages to specify a transient river boundary condition in simulation of the seasonal hydrograph, through wet spring and dry summer periods. For each of three channel re-alignment alternatives, SSP&A simulated groundwater conditions and surface water exchanges relevant to the objective of sustaining wetlands and of maintaining flows in the river channel for downstream water delivery and for aquatic species.