The City of Austin’s flagship environmental monitoring program, the Environmental Integrity Index (EII), is a tool used to assess the hydrology, water quality, geomorphology and biology of all streams within the City’s jurisdiction. Hydrology is the mechanism for sediment and constituent transport within streams; therefore, accurate records of continuous discharge are necessary to compute stream pollutant loads and assess long-term biologic integrity. Traditional rating curve development often requires months or years of discharge measurements to establish site-specific relationships between continuously monitored stage and computed discharge. High-flow events further complicate data collection due to safety constraints and specialized equipment. Alternatively, theoretical rating curves can be developed using hydraulic modeling, but these models represent fixed conditions and may not capture current or dynamic site conditions. To accelerate rating curve development, we implemented a hybrid strategy that integrates hydraulic modeling with field data. This effort was initiated after observing issues in our original models, such as hydraulic control structures at modeled elevations lower than the gage pools they create. We developed provisional rating curves in HEC-RAS 1D, a river hydraulics modeling software, by updating terrain-based floodplain models with surveyed cross-sections and structural measurements. Overall, the revised cross sections were consistently deeper than the original digital elevation map, and the slopes varied along the surveyed stream sections. These hydraulic models will be further refined over time using flow rates from wading measurements to update model coefficients and ensure models respond to seasonal site conditions. This approach enables us to immediately estimate flow and associated uncertainty while establishing a protocol for iterative refinement of rating curves. Thus, pollutant loading can also be more accurately estimated.