Modeling a Bioretention Basin and Vegetated Swale with a Trapezoidal Cross Section using SWMM LID Controls

Abstract

The Low Impact Development (LID) Control module is utilized in the United States Environmental Protection Agency’s Stormwater Management Model (USEPA SWMM) to predict the hydraulic performance of a variety of sustainable stormwater technologies. Data collected in 2019 from the monitoring of a pilot project in Montreal was used to verify the ability of the Bioretention LID Control (which assumes a rectangular cross-section) to accurately simulate outflow from a structure with a trapezoidal cross-section. Two types of LID facility were modeled: one releases captured inflow through a perforated underdrain below the soil layer (bioretention basin; BB); and the other is drained at the surface of the soil layer (vegetated swale; VS). Initially, the modeled LID structures were sized identically to the field surface areas. However, it was necessary to change their model representation to account for the non-rectangular shape of the soil layer. In addition, a sensitivity analysis was completed, and the most influential parameters were identified as the conductivity slope and seepage rate. Both the alteration of the LID structure representation and the parametric calibration greatly improved the simulated outflows from the vegetated swale resulting in an increase of the Nash–Sutcliffe efficiency (NSE) coefficient from −0.6 to 0.64 (NSE >0.5 is acceptable for hydrologic models according to the literature). The bioretention basin calibration did not prove as successful. The evaluated LID Control module presented better predictive capabilities for the basin with a simpler overall design (VS).

New Bioretention Drainage Channel as One of the Low-Impact Development Solutions: A Case Study from Poland

“…The catchment and bioretention drainage channel characterisation data used in the hydrodynamic model of the catchment are shown in Tables 1 and 2. The input data were adopted from recommendations by the U.S. Environmental Protection Agency [45] and other studies [46,47]. In the SWMM programme, precipitation is transformed into an effective runoff, determined as the runoff from a linear basin whose filling is equal to the amount of water that fell on a given surface after taking into account losses due to evaporation, soaking, and water retention in depressions in the land.…”

Analysis of Effect and Necessity of Perforated Pipes by Type of Runoff in Bio-retention

“…Research on the existing vegetation settlements mainly focuses on water circulation improvement (Jeon et al, 2021;Choi et al, 2021). ;), studies on pollutant reduction (Shin and Gil., (Bond et al, 2021) were conducted. However, there is no need for a perforated drainpipe in the manuals on domestic and foreign bio-retention.…”