New Mexico Geological Society Annual Spring Meeting — Abstracts

The Low Flow Conveyance Channel is a deep drain channel constructed parallel to the Rio Grande in the Socorro reach of central NM. Its management uses have varied over the decades, and the Interstate Stream Commission (ISC) would like future operations to be based on an improved scientific understanding of the hydrologic system. Several preliminary assessments, based on the data obtained to date, provide initial insights into the spatial and temporal variation of the flows within the LFCC from San Acacia to San Marcial. First, three discharge time series were generated by applying stage-discharge rating curves to recorded water levels at three locations within Bosque del Apache Nation Wildlife Refuge (BdA). These rating curves are based on manual measurements collected from June 2024 to February 2026, with a power-law fit that captures the relationship between water level and discharge well (R²>0.93). The seasonal pattern of irrigation activities from March to October noticeably influenced the relative values and variation in monthly discharge within the LFCC, while the elevated discharges from November to February remained consistent. An average discharge gain of approximately 1.5 m³/s was observed monthly across the 18-km reach from the north border to the south border of BdA. Moreover, the inflow-outflow measurements conducted in May, July, and September 2025 reveal a linear correlation between increasing seepage gains and higher flows in LFCC, likely associated with higher flows in the Rio Grande. While this trend was observed at 5 of 8 reaches on the LFCC, farther upstream and downstream of BdA, the remaining reaches showed seepage gains at lower flow rates but increasing losses as the flow rate rose. These integrated results indicate that seepage gains and losses do not only vary seasonally (e.g., greatest gains during high flow in May) but also spatially within LFCC (ranging from 0.02 to 0.4 m³ s^-1 km^-1).