System For Urban Stormwater Treatment And Analysis Integration Research Articles

Integrated SUSTAIN-SWMM-MCDM Approach for Optimal Selection of LID Practices in Urban Stormwater Systems

Rapid urbanization has increased impervious areas, leading to a higher flood hazard across cities worldwide. Low Impact Development (LID) practices have shown efficacy in reducing urban runoff; nevertheless, choosing the best combinations in terms of implementation cost and performance is of great importance. The present study introduces a framework based on green infrastructure, multi-objective optimization, and decision support tools to determine the most cost-effective LID solutions. The Storm Water Management Model (SWMM) was employed for rainfall-runoff and hydraulic modeling in Region 1, District 11 of Tehran, Iran. Six scenarios of different combinations of LID practices were developed. The system for Urban Stormwater Treatment and Analysis Integration (SUSTAIN) was used to optimize and evaluate each scenario. The selected solutions were imported to the SWMM to evaluate the stormwater system performance. Then, two multi criteria decision making (MCDM) models, including TOPSIS and COPRAS, were employed to rank the scenarios based on four technical and economic criteria. Results showed that scenario 4, consisting of rain barrels, porous pavements, and vegetated swales, had the best performance under TOPSIS with a 7.68 million USD and reduced the runoff volume and peak flow by 20.77% and 19.2%, respectively. However, Under the COPRAS method, Scenario 2 with a combination of rain barrels, bio-retention cells, and vegetated swales showed higher performance than the other scenarios with 3.25 million USD and led to a 15% reduction in the runoff volume and 4.30% in the peak flow. The COPRAS method was more sensitive to cost weights and chose the most economical scenario as the ideal. However, Scenario 4 concluded to be more feasible due to spatial limitations in the study area. The proposed SWMM—SUSTAIN—MCDM framework could be helpful to decision-makers in the design, performance evaluation, cost estimation, and selection of optimal scenarios.

Planning and optimization of green infrastructures for stormwater management: The case of Tehran West Bus Terminal

AbstractGreen Infrastructures as Best Management Practice (GI‐BMP) play important role in preserving cities from urban flood and excessive runoff. In the process of using GI‐BMP in cities for stormwater management, a number of steps are taken that normally include selection of suitable sites, formulating proper combination of infrastructures, and optimization of the place and design of GI‐BMPs to maximize their cost‐effectiveness. This paper presents a site‐scale GI‐BMP implementation in Tehran West Bus Terminal (TWBT), Iran. To achieve this goal, this study applies a three steps framework namely GI‐BMP suitability analysis, GI‐BMP combination planning, and GI‐BMP optimization. In the first step, using the BMP Siting Tool, the suitable places for allocating GI practices were identified. In the next step, suitable GI‐BMP practices, including permeable pavements, bioretention basin, infiltration trench, and rain barrel were planned and arranged for each subwatersheds of the study area. In the third step, with the use of System for Urban Stormwater Treatment and Analysis Integration (SUSTAIN) model and NSGA‐II algorithm, the sizes of the planned GI‐BMP types were optimized for each subwatershed. The results indicate that runoff problem caused by surface runoff in the study area was serious and needed to be controlled. The results also revealed that there were 104 near‐optimal solutions that help reduce runoff volume by up to 70%. According to the results, applying GI‐BMPs in TWBT will reduce 60% of flow volume in the site with the price of 353,568$. This research is of practical importance for stormwater management using nature‐based solutions in bus terminals.

Investigating Tradeoffs of Green to Grey Stormwater Infrastructure Using a Planning-Level Decision Support Tool

Integrated decision support tools are needed to investigate the tradeoffs of stormwater control measures (SCMs) and determine the optimal suite of SCMs based on the needs of watersheds. In this study, an urbanized watershed undergoing infill development (the Berkeley neighborhood located in Denver, CO, USA) was modeled using a modified version of the U.S. Environmental Protection Agency’s (EPA) System for Urban Stormwater Treatment and Analysis IntegratioN (SUSTAIN). The primary goal was to compare the relative performance between green and grey SCMs, use optimizations and a planning-level approach to assist in decision-making, and discuss how stakeholder and community preferences can shift which SCMs are optimal for the watershed. Green and grey SCMs have variable hydrologic performance based on design and function, and both offer benefits that may be important to decision makers. Our results showed that infiltration trenches and underground infiltration were optimal for reducing flow volumes while vegetated swales and underground detention were optimal for pollutant concentration reduction. Stakeholders value both of these benefits and so the optimal stormwater solution in the Berkeley neighborhood included a mix of green and grey SCMs. Determining the optimal SCMs while considering tradeoffs in costs and associated benefits was complex and multifaceted. Modeling results such as those presented here are critical for informing stakeholders’ decision-making process.

Towards efficient Low Impact Development: A multi-scale simulation-optimization approach for nutrient removal at the urban watershed

In this study, we proposed a multi-scale modelling framework for Low Impact Development (LID) by integrating (i) local-scale LID cost-effectiveness analysis, (ii) landscape-scale Management Category (MC) classification and LID selection, and (iii) macro-scale integrative decision making. The framework was used for sitting LID to reduce Total Phosphorus (TP) loss in the City Kunming regional watershed, which discharges massive urban Non-Point Source (NPS) pollution to Lake Dianchi, one of the three most eutrophic large lakes in China. Local-scale simulation-optimization was performed to optimize the sizes and quantities of the candidate LID practices with the System for Urban Stormwater Treatment and Analysis Integration (SUSTAIN) tool. The Non-dominated Sorting Genetic Algorithm II (NSGA-II) was used to solve the optimization problem. The local-scale LID strategies were ultimately integrated at the macro scale in compliance with the water quality standards. Our analysis suggests that the marginal benefits of LID implementation decline dramatically with increasing TP abatement attributed to the law of Diminishing Marginal Benefits. The areal cost-effectiveness curves of different scenarios resemble each other for the same MC since the Coefficients of Variation (CVs) of unit costs are mostly below 10%. Spatial variability of LID implementation is more prominently affected by disparities of landscapes than drainage area sizes because the coverage ratios among different MCs vary from 2.3% to 24.7% whereas they resemble each other among different area sizes. The multi-scale decision-making framework could dramatically improve computational efficiency by reducing the model runs from 923 to 23 compared to the conventional full-watershed simulation-optimization.

Cost-effectiveness Analysis of Green-Gray Stormwater Control Measures for Non-Point Source Pollution.

The control of non-point source pollution (NPS) is an essential target in urban stormwater control. Green stormwater control measures (SCMs) have remarkable efficiency for pollution control, but suffer from high maintenance, operation costs and poor performance in high-intensity rainfall events. Taking the Guilin Road subwatershed in Rizhao, China, as a case study, a scheme for coupling gray and green stormwater control measures is proposed, and the gray SCMs are introduced to compensate for the shortcomings of green SCMs. The System for Urban Stormwater Treatment and Analysis Integration (SUSTAIN) model was employed to investigate the cost-effectiveness of three scenarios (green SCMs only, gray SCMs only, and coupled green–gray SCMs). The results show that the optimal solutions for the three scenarios cost USD 1.23, 0.79, and 0.80 million, respectively. The NPS control ability of the coupled green–gray scenario is found to be better than that of the other two scenarios under rainfall events above moderate rain. This study demonstrates that coupled green–gray stormwater control management can not only effectively control costs, but can also provide better pollution control in high-intensity rainfall events, making it an optimal scheme for effective prevention and control of urban non-point source pollution.

Can floor-area-ratio incentive promote low impact development in a highly urbanized area?—A case study in Changzhou City, China

As an environmental friendly measure for surface runoff reduction, low impact development (LID) has been applied successfully in urban areas. However, due to high price of land and additional expense for LID construction in highly urbanized areas, the developers of real estate would not like to proceed LID exploitation. Floor area ratio (FAR) refers to “the ratio of a building’s total floor area to the size of the piece of land upon which it is built.” Increasing FAR indicates that the developers can construct higher buildings and earn more money. By means of awarding FAR, the developers may be willing to practice LID construction. In this study, a new residential district is selected as a case study to analyze the tradeoff between the runoff reduction goal achieving by LID practices and the incentive of awarding FAR to promote LID construction. The System for Urban Stormwater Treatment and Analysis IntegratioN (SUSTAIN) model is applied to simulate the runoff reduction under various LID designs and then derive the Pareto-optimal solutions to achieve urban runoff reduction goals based on cost efficiency. The results indicates that the maximum surface runoff reduction is 20.5%. Under the extremity scenarios, the government has options to award FAR of 0.028, 0.038 and 0.047 and the net benefits developers gain are 0 CNY, one million CNYand two million CNY, respectively. The results provide a LID construction guideline related to awarding FAR, which supports incentive policy making for promoting LID practices in the highly urbanized areas.

Evaluation of wetland implementation strategies on phosphorus reduction at a watershed scale

Excessive nutrient use in agricultural practices is a major cause of water quality degradation around the world, which results in eutrophication of the freshwater systems. Among the nutrients, phosphorus enrichment has recently drawn considerable attention due to major environmental issues such as Lake Erie and Chesapeake Bay eutrophication. One approach for mitigating the impacts of excessive nutrients on water resources is the implementation of wetlands. However, proper site selection for wetland implementation is the key for effective water quality management at the watershed scale, which is the goal of this study. In this regard, three conventional and two pseudo-random targeting methods were considered. A watershed model called the Soil and Water Assessment Tool (SWAT) was coupled with another model called System for Urban Stormwater Treatment and Analysis IntegratioN (SUSTAIN) to simulate the impacts of wetland implementation scenarios in the Saginaw River watershed, located in Michigan. The inter-group similarities of the targeting strategies were investigated and it was shown that the level of similarity increases as the target area increases (0.54–0.86). In general, the conventional targeting method based on phosphorus load generated per unit area at the subwatershed scale had the highest average reduction among all the scenarios (44.46t/year). However, when considering the total area of implemented wetlands, the conventional method based on long-term impacts of wetland implementation showed the highest amount of phosphorus reduction (36.44t/year).

Placement of BMPs in urban catchment area using SUSTAIN model: case study at Universitas Indonesia Campus, Depok, West Java, Indonesia

Aquatic system quality degradation by urban runoff owing to the effect of increasing impervious cover due to urbanization is becoming a serious issue. Based on 2015 data, with total imperviousness more than 60% in aquatic system catchment area of Universitas Indonesia (UI) Campus, the aquatic system quality is in poor condition. Best Management Practices (BMPs) as the practical form of Low Impact Development (LID) concept are proposed to be implemented in the catchment area. The performance of BMPs implementation can be quantitatively assessed using System for Urban Stormwater Treatment and Analysis Integration (SUSTAIN) model developed by US Environmental Protection Agency. As a decision support system, SUSTAIN model as the extension of ArcGIS can be applied for placement of BMPs at strategic locations in urban watersheds. This study aims to find the suitable location of BMPs placement in nine sub-catchments of UI Campus aquatic system catchment area. The suitability criteria for placing structural BMPs comprise nine database layers including slope, soil type, urban land use, percent impervious, land ownership, roads, water table depth, stream location, and drainage area. The study shows that there are ten types of BMPs that suitable to be implemented in UI campus catchment area, while three types of BMPs are not suitable. Based on the validation analysis, the applicable result from SUSTAIN model is 18 of 20, or has 90 percent of trust.

Modeling the cost-effectiveness of stormwater best management practices in an urban watershed in Las Vegas Valley

The Las Vegas Valley is one of the fastest growing urban areas in the United States. Any future urbanization and climate change, especially if the climate becomes wetter and there are more intense and frequent storm events, will undoubtedly cause excessive urban stormwater runoff and exacerbate flooding in the Valley. Stormwater management is therefore one of the key challenges to the local government. The main goal of this study was to ascertain the utility of Best management Practices (BMPs) in mitigating stormwater runoff in the Duck Creek watershed in the Las Vegas Valley. The cost-effectiveness of different BMPs were also compared so as to determine the best BMP arrangement under the current and future climate and land use change conditions. By applying SUSTAIN (System for Urban Stormwater Treatment and Analysis INtegration) as a comprehensive GIS-based modeling and decision support system in the BMP analyses, modeling results show that although the installation of the existing three detention basins in the watershed can provide a 9% flow reduction, these three detention basins alone will not be adequate in the future with the impending changes in climate and land use. To alleviate the potential problems of water resources, SUSTAIN was further used to determine the number of additional BMPs required, the optimal types of BMPs (such as, detention and infiltration BMPs), and their locations in reducing storm runoff in the watershed under the future land-use and climate regimes. By comparing the performances of five potential BMP implementation scenarios, it was found that a mixed implementation of one additional detention BMP and one infiltration BMP to the existing detention BMPs in the downstream area of the watershed would be the most cost-effective stormwater runoff control solution in face of future urbanization and climate change. Depending on the locations of the new detention and infiltration BMPs, surface flow, even without BMP retrofit options, could be reduced by 27–31%. The cost for such installations would range from $1,141,000 to $1,319,000. This information may be useful to local planners and water resource managers in their efforts to develop alternative stormwater management plans in the arid Southwest.

Application of BMP to urban runoff control using SUSTAIN model: Case study in an industrial area

Flooding and stormwater pollution by urban runoff owing to the effects of urbanization and industrialization on both hydrology and water quality have become a serious issue. Best management practices (BMP) are proposed to mitigate floods and reduce pollutants, the performance of which can be quantitatively assessed by the System for Urban Stormwater Treatment and Analysis Integration (SUSTAIN) model. A factory in the city of Ma’anshan, China was selected as a case study for planning and analysis of BMP. First, surface runoff pollution was identified as being caused by different land uses at this site. BMP such as permeable pavements, vegetated swales, green roofs, wet ponds, and bioretention basins were planned for this site. After BMP planning, system performance was evaluated using SUSTAIN. Sizes of the implemented BMP were further adjusted using the optimization module of SUSTAIN. Quantitative analyses of pollutant purification and flood mitigation ecosystem services after optimization were conducted. The results indicate that pollution caused by urban surface runoff in the study area was serious and required treatment. Compared with the developed condition, the BMP plan would reduce total runoff volume, total suspended solid load, dissolved zinc load, total nitrogen load, total phosphorus load and chemical oxygen demand load by 41%, 62%, 55%, 57%, 55% and 60%, respectively. This research result is of practical importance for urban nonpoint source pollution caused by industrial activities.

Assessing the significance of wetland restoration scenarios on sediment mitigation plan

Wetlands have many environmental, social, and economic values. However, due to accelerated land use change and lack of understanding of the functions of wetland ecosystems, they have deteriorated, if not been lost in many areas worldwide. Meanwhile, current functional wetland assessment techniques only provide rough estimations, and are in most cases site specific and qualitative. The overall goal of this project is to examine the sediment reduction benefit of wetland implementation scenarios both at subbasin and watershed scales. Two sets of models were used to accomplish this goal. First, a watershed model – the Soil and Water Assessment Tool (SWAT), was employed to estimate sediment load at the subbasin scale. However, due to limitations of wetland functions of SWAT, a second model – the System for Urban Stormwater Treatment and Analysis Integration (SUSTAIN) was used. The sediment load generated for each subbasin was incorporated in the SUSTAIN model. This allows for evaluating sediment reduction capability of wetlands at subbasin level. Next, a portion of sediment not treated by a wetland was fed back to the SWAT model and routed to the watershed outlet. The impacts of four different wetland surface areas (0.40, 0.81, 2, and 4ha) on sediment load mitigation were examined one-at-a-time for all subbasins within the River Raisin watershed located in southeastern Michigan and northeastern Ohio. Comparison of the sediment reductions due to different wetland restoration scenarios reveals the importance of wetland placement in a watershed. In general, the rate of streamflow reduction resulting from wetland implementation is higher than sediment reduction at the subbasin level but more comparable at the watershed level. In addition, clusters of wetlands installed at the distance of 150–200 stream km from the outlet outperformed other clustered wetlands at closer and farther distances. Wetlands associated with 1st order streams performed better at the subbasin level, while wetlands located at 4th order streams performed better at the watershed level. Considering environmental and economic issues of wetland restoration scenarios revealed that the 0.4ha wetlands were the most suitable for subbasin and watershed level implementation due to its sediment reduction efficiency and significantly lower cost of installation and maintenance.

Evaluation of a hydrology and run-off BMP model in SUSTAIN on a commercial area and a public park in South Korea

Adapting best management practices (BMPs) is influenced by target reduction efficiency BMP size, and BMP type. The System for Urban Storm water Treatment and Analysis INtegration (SUSTAIN) model was evaluated to determine optimal size and type of BMP with monitoring results from a commercial area and a public park in Korea. The hydrology model in SUSTAIN was tested in a commercial area (impervious area: 85%) and a public park (impervious area: 36%) in South Korea. A sensitivity analysis revealed that the significant parameters for total flow were impervious area Manning’s roughness (IMPN) and saturated hydraulic conductivity (HYDCON); and those for peak flow were IMPN, Manning’s roughness of conduit (ROUGH) and HYDCON. The observed average run-off ratios of the two study sites were 0.59 and 0.30 for the commercial area and the public park, respectively. In contrast, the simulated average run-off ratios were 0.53 and 0.22, respectively. The SUSTAIN hydrology model was also evaluated statistically by comparing observed and simulated run-off. In a commercial area, R2, root mean square error, and Nash–Sutcliffe efficiency were 0.68, 10.98, and 0.46, respectively, whereas the public park yielded 0.74, 1.97, and 0.62, respectively. After calibrating the model, the BMP options of SUSTAIN (i.e. bioretention, dry pond, and wet pond) were utilized to test run-off reduction capability with 11 mm of retaining run-off depth from the commercial area and 3 mm from the public park. Monitoring data showed that 11 and 3 mm run-off storage ensured about a 50% reduction of run-off from the commercial area and the public park, respectively. In the commercial area, average reduction rates were identically all 43.0% for bioretention, dry pond, and wet pond, respectively, and those for the public park were 49.6, 57.6, and 53.5%, respectively. Overall, the BMP function of SUSTAIN seemed to be reasonable for reducing run-off and could be used to design BMP to meet a target reduction goal where monitoring data does not exist.

SUSTAIN Applications for Mapping and Modeling Green Stormwater Infrastructure

The United States Environmental Protection Agency’s System for Urban Stormwater Treatment and Analysis Integration (SUSTAIN) software program is a GIS ba…

A watershed-scale design optimization model for stormwater best management practices

U.S. Environmental Protection Agency developed a decision-support system, System for Urban Stormwater Treatment and Analysis Integration (SUSTAIN), to evaluate alternative plans for stormwater quality management and flow abatement techniques in urban and developing areas. SUSTAIN provides a public domain tool capable of evaluating the optimal location, type, and cost of stormwater best management practices (BMPs) needed to meet water quality and quantity goals. It is a tool designed to provide critically needed support to watershed practitioners in evaluating stormwater management options based on effectiveness and cost to meet their existing program needs. SUSTAIN is intended for users who have a fundamental understanding of watershed and BMP modeling processes. How SUSTAIN is setup described here using a case study, conducted by actual data from an existing urban watershed. The developed SUSTAIN model was calibrated by observed rainfall and flow data, representing the existing conditions. The SUSTAIN model developed two BMP cost-effectiveness curves for flow volume and pollutant load reductions. A sensitivity analysis was also conducted by varying important BMP implementation specifications.