Model Files for "Effectiveness of Stormwater Control Measures in Protecting Stream Channel Stability"

This resource archives Model files supporting the paper "Effectiveness of Stormwater Control Measures in Protecting Stream Channel Stability".
The abstract for this paper follows: "While research on the hydrologic impact of different types of stormwater control measures (SCMs) is extensive, little research exists linking urbanization, widespread implementation of SCMs, and channel stability in headwater streams. This study evaluated whether the Unified Stormwater Sizing Criteria (USSC) regulations in the state of Maryland, USA, which require the use of both end-of-pipe and distributed, small-scale SCMs, protect channel stability. To achieve this goal, a coupled hierarchical modeling approach utilizing the Storm Water Management Model (SWMM) and the Hydrologic Engineering Center River Analysis System 6.3 (HEC-RAS) was developed to predict changes in streamflow and sediment transport dynamics in a first-order gravel-bed, riffle-pool channel. Storm event discretization revealed that 88% of observed storm events during the 16 years (2004-2020) had durations less than 18 hours and that the greatest peak flows resulted from storm events with durations less than 24 hours. HEC-RAS simulation results also showed that both channel degradation and aggradation, as high as 1.2 m, will likely occur regardless of the combination of SCMs employed in the catchment. Overall, this study provides valuable insights into the complex interactions between SWM practices, flow regimes, and sediment transport dynamics in heavily urbanized watersheds. It is recommended that SCMs be designed using a continuous simulation model with at least 10 years of continuous rainfall data. Furthermore, to protect channel stability, the SCM design goal should focus on maintaining pre-development sediment transport regimes across a range of flows."