Discharge-Stage Relationship on Urban Streams Evaluated at USGS Gauging Stations, St. Louis, Missouri

Generation and Propagation of an Urban Flash Flood and Our Collective Responsibilities

“…Thus, water depths can be easily determined from the pressures measured by the in-stream sensors, by making standard corrections for barometric pressure and for temperature-dependent water density. Stream gauge 07010022 on the uRdP also recorded water levels at 5 minute intervals and is calibrated for discharge; additional gauges 07010030 and 0710035 provide data for two downstream tributaries (USGS, 2022; Criss and Nelson, 2020). Third, the Missouri Department of Transportation established an extensive system of topographic benchmarks in St. Louis County (MODOT, 2020).…”

Stage-based flood inundation mapping

“…𝐻 𝑇 = ℎ 𝑇 − ℎ 0 (9) Criss and Nelson (2020) provide several ways to determine ho at any gauged site.…”

“…Flows estimated by FEMA and USACE for given water levels are commonly at great odds with USGS rating tables (Criss, 2016). Moreover, USGS rating tables for small streams are mostly based on great extrapolations of measurements at low water levels that have minimal relevance to flooding (Criss and Nelson 2020). Finally, regarding the uRdP in particular, HUD (1978) pointed out that flows estimated by FEMA and USACE for extreme events are probably too large to be conveyed by the tunnel immediately downstream.…”

“…Average annual rainfall in the last 25 years has been 107±21 cm (NWS 2020b), but sharp convective storms that deliver ≥4cm of rain per hour occur during most years (NOAA 2017). Such storms induce flash floods on many St. Louis creeks, which can rise as rapidly as 3m/h (Criss and Nelson 2020). The upper River des Peres (uRdP; 25.0 km 2 ) and Deer Creek (DCK; 95.2 km 2 ) sub-basins of the RdP are considered in detail below (Fig.…”

Stage-Based Flood Inundation Mapping

“…Flows estimated by FEMA and USACE for given water levels are commonly at great odds with USGS rating tables (Criss, 2016). Moreover, USGS rating tables for small streams are mostly based on great extrapolations of measurements at low water levels that have minimal relevance to flooding (Criss and Nelson 2020). Finally, regarding the uRdP in particular, HUD (1978) pointed out that flows estimated by FEMA and USACE for extreme events are probably too large to be conveyed by the tunnel immediately downstream.…”