Decision-Support System for LID Footprint Planning and Urban Runoff Mitigation in the Lower Rio Grande Valley of South Texas

Javier Guerrero,Taufiqul Alam,Ahmed Mahmoud,Andrew Ernest,Kim D Jones

doi:10.3390/su12083152

Javier Guerrero, Taufiqul Alam + Show 3 more

Open Access

https://doi.org/10.3390/su12083152

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Abstract

To address regional flooding in the United States, federal and state agencies are adopting strict drainage policies in any large-scale commercial development within the watershed boundary. The conventional approach of implementing a wet detention pond (WP) reduces the land cover and causes operation and maintenance challenges eventually. The present study developed a decision-support system (DSS) in the Lower Rio Grande Valley region of South Texas for optimal selection of Best Management Practices (BMPs) by substituting a portion of the WP footprint with three regionally promising low-impact development practices, namely, porous concrete pavement (PCP), bioretention (BR), and bioswale (BS). Source Load Assessment and Management Model for Windows (WinSLAMM) was used as the foundation for the DSS database and algorithm development. This tool suggested that the implementation of bioswale alone can considerably reduce the footprint and construction cost. Less than 0.95 ha of installation of BR and BS can mitigate 79–91% of runoff from a maximum of 5 ha of commercial development. A combination of BR, BS, and WP was found to reduce runoff significantly (~100%), which suggests that the successful adoption of DSS might support better planning of the urban stormwater management in the Lower Rio Grande Valley (LRGV).

Highlights

Rapid urbanization and industrialization have significantly fueled the total percentage of impervious land cover within the major watersheds of the United States (US) [1,2,3,4]
Previous studies observed that the outflow volume followed a curvilinear trend as rainfall magnitude increased
The goodness of fit and the statistical correlation between observed and simulated results were determined through the Kling-SGusutapinatbailitEy ffi202c0,i1e2n, xcFyOR(KPEGERER)E,VRIEoWot Mean Square Error (RMSE), and regression h8yopf 1o9thesis test (p-value)

Summary

Introduction

Rapid urbanization and industrialization have significantly fueled the total percentage of impervious land cover (such as traditional parking lots driveways, sidewalks, roofs, etc.) within the major watersheds of the United States (US) [1,2,3,4]. Urban land developments increased by four times between the years 1945 and 2010 [5], which eventually altered the watershed hydrology and triggered an uncontrolled runoff towards major rivers in the US [6]. The first flush of urban runoff carries non-point source (NPS) pollutant load, which eventually adversely affects the water quality of the watershed [7,8,9]. Designing detention ponds is somewhat effective and the calculation of storage is simple using Excel spreadsheets, this approach may cause the reduction of land cover; problems with safety, operation, and maintenance; and aesthetic issues in the future [14]. Communities have been stressing successful planning of innovative stormwater management techniques to reduce non-point source pollutants; to mitigate localized flooding in urban, colonial, and rural settings; and to improve water quality [15]

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