Modeling Operations in System-level Real-time Control for Urban Flooding Reduction and Water Quality Improvement -An Open-source Benchmarked Case

Abstract

Increases in the integrated application of smart sensing and control technologies enable urban drainage engineers to retrofit stormwater storage facilities with controllers actuating valves and gates to address flooding and water quality problems across the entire watershed. This objective becomes increasingly challenging because simultaneously controlling the spatially distributed storage assets to solve the stormwater issue at downstream outlet sites does not necessarily alleviate overflow at upstream storage ponds. To that end, this study presents a system-level real-time control simulation for assessing the performance of controllers in the trade-off between flooding mitigation at downstream outlets and water quality improvements at the upstream storage units like the detention pond. Using a benchmarked urban stormwater drainage model located in the southeast of Michigan, USA, with watershed-scale flooding and water quality challenges, we investigated the temporal changes in water depth, flow, and total suspended solids under different real-time control strategies, including one individual control operated only at the most downstream outlet site and two system-level controls operated at all storage detention sites. Modeling results show that the system-level control reduces peak water depth, shortens flooding duration, and removes pollutant load, by up to 7.3%, 34%, and 65%, respectively. However, system-level control does not always perform better than the individual control strategy, especially in addressing flooding duration in the most downstream outlet. This modeling work advances real-time control understanding for building adaptive stormwater management solution against water quantity and quality issues.

An Event-Based Resilience Index to Assess the Impacts of Land Imperviousness and Climate Changes on Flooding Risks in Urban Drainage Systems

“…Traditionally, the flooding resilience index Res 0 is estimated as one minus the computed volumetric flooding severity, shown in Equation (5). However, the traditional flooding resilience Res 0 has limitations in adopting mean nodal flooding duration to represent the system flooding duration.…”

“…However, most of the existing UDSs are designed on the basis of historical climate statistics and maintained by the assumption of the constant urban land surfaces [2]. These conventional designs will be likely to over-estimate the reliability of UDSs that consequently become vulnerable to future external or internal failures or disturbances, such as extreme rainfall, urban impervious cover changes, sewer sedimentation, equipment malfunction, manhole collapse, and pipe blockage [3][4][5]. The concerns for performance deterioration in traditional UDSs are rising in metropolitan areas since the severity of flooding is predicted to continue or be aggravated due to future climate and land cover change [6][7][8].…”

Evaluating real-time control of stormwater drainage network and green stormwater infrastructure for enhancing flooding resilience under future rainfall projections

“…Implementing RTC involves retrofitting (or building with new) UDSs with water level sensors, flow sensors, actuators, and moveable gates to achieve real-time sensing and controlling of system operations (Marchese et al, 2018;Schütze et al, 2004). Sensors provide real-time system states for actuators, which accordingly open or close gates to some extent until the next sensed information changes operations (Li et al, 2023;Li et al, 2020bLi et al, , 2019a. UDSs can be controlled in real-time to make full use of the available or under-used storage capacity, to retain water in a tank and GSI, or to selectively discharge water before the next storm comes (Lewellyn and Wadzuk, 2017).…”

The Performance Comparison between RTC and GI to Mitigate Impacts of Climate Change and Urban Redevelopment on Urban Flooding

“…Sensors provide real-time system states for actuators, which accordingly open or close gates to some extent until the next sensed information enters the RTC system. In this way, UDSs can be controlled in real-time to make full use of the available or under-used storage and conveyance capacity to selectively discharge water in the pipe during a storm or to retain water in the tank before the next storm comes (Li et al 2023a). RTC has been widely adopted for various stormwater objectives.…”