Stormwater Management Tool Research Articles

Site-Scale Integrated Decision Support Tool (i-DSTss) for Stormwater Management

A site-scale integrated decision support tool (i-DSTss) is developed for selection and sizing of stormwater Best Management Practices (BMPs). The tool has several component modules—hydrology, BMP selection, BMP sizing, and life-cycle cost analysis (LCCA)—integrated into a single platform. The hydrology module predicts runoff from small catchment on event and continuous basis using the Green-Ampt and Curve Number methods. The module predicted runoff from a small residential area and a parking lot with R2 value of 0.77 and 0.74, respectively. The BMP selection module recommends a BMP type appropriate for a site based on economic, technical, social and environmental criteria using a multi-criteria optimization approach. The BMP sizing module includes sizing options for green roofs, infiltration-based BMPs, and storage-based BMPs. A mass balance approach is implemented for all types of BMPs. The tool predicted outflow rates from a permeable pavement with R2 value of 0.89. A cost module is included where capital, operation and maintenance, and rehabilitation costs are estimated based on BMP size obtained from the sizing module. The i-DSTss is built on an accessible platform (Microsoft Excel VBA) and can be operated with a basic skillset. The i-DSTss is intended for designers, regulators, and municipalities for quick analysis of scenarios involving interaction among several factors.

Assessment of different MOEAs for rehabilitation evaluation of Urban Stormwater Drainage Systems – Case study: Eastern catchment of Tehran

Design/rehabilitation of urban stormwater drainage systems has become a challenging issue due to increasing frequency and severity of floods in urbanized areas. Optimization frameworks can provide a proficient computational tool for stormwater management. In this study, using four different optimization algorithms and EPA-SWMM (Environmental Protection Agency -StormWater Management Model) software, a coupled numerical and optimization model was developed to rehabilitate the drainage system in eastern Tehran, Iran. The current drainage network suffers from a significant lack of hydraulic capacity. Thus, combinations of relief tunnels and/or storage units were evaluated and optimal rehabilitation strategies were suggested according to minimizing conflicting objective functions of costs and flooding. Results have revealed that AMALGAM (A Multi-ALgorithm, Genetically Adaptive Multi-objective) outperformed three other algorithms, NSGA-II (Non-dominated Sorting Genetic Algorithm-II), NSHS (Non-dominated Sorting Harmony Search), and NSDE (Non-dominated Sorting Differential Evolution) for the evaluation of rehabilitation of Urban Stormwater Drainage Systems (USDSs) in terms of convergence and diversity criteria.

Long‐term and seasonal hydrologic performance of an extensive green roof

AbstractSustainable strategies such as green roofs have been implemented as stormwater management tools to mitigate disturbance of the hydrologic cycle resulting from urbanization. Green roofs, also referred to as vegetated roofs, can improve the urban landscape by reducing heat island effects, providing ecosystem services, and facilitating the retention and treatment of stormwater. Green roofs have received particular attention because they do not require acquisition and development of land and represent an application of biomimicry in design and construction. In this paper, we evaluate the effects of precipitation, evapotranspiration (ET), antecedent dry period (ADP), and seasonal variation on the run‐off quantity and distribution of an extensive, sedum covered, green roof on a commercial building in Syracuse, NY, USA. The green roof greatly facilitated retention of precipitation events without significant changes over the 4‐year study. The green roof retained on average 95.9 ± 3.6% (6.5 ± 5.6 mm) per rainfall event, with a range from 75% to 99.6% (33.2 to 3.3 mm). However, as precipitation quantity increased, the retention of water decreased. This high water retention capacity was the result of the combined effects of ET, stormwater storage (plants, growth media, and stormwater retention layer), and limited surface run‐off from the roof deck due to variation in the sloping of the green roof and the tapered insulation to the deck drains. The water retention capacity of the green roof did not change significantly between growing and nongrowing seasons. Slightly greater precipitation during the growing season coincided with increased ET. Average potential ET during the growing season was approximately 3 times greater than during the nongrowing season. The hydrologic performance of the green roof was not significantly impacted by an ADP greater than 2 days.

Study on identically voided pervious concrete made with different sized aggregates

Pervious concrete (PC) is also known as no fines concrete and has been found to be a reliable stormwater management tool. As a substitution for conventional impervious pavement, PC usage has been increasing during recent years. PC made with different sized aggregate shows different void ratios and changed properties. As void ratio plays a notable role on strength and permeability of PC, this study aims to focus on properties of PC at identical void ratio of 20%, made using aggregates of three size ranges, viz., 4.75-6mm, 10-12.5mm, and 10-20mm. Appropriate alternatives were used to maintain the identical void ratio.As the permeation capacity of PC gets reduced due to the clogging tendency, the life of PC will also get reduced. Hence, to make the PC to sustain for a long time it is necessary to study the clogging behavior. This study investigates the tendency of PC for clogging and the potential for regaining the permeability through de-clogging methods. Clogging tendency of PC is studied by using two sizes (coarse and fine) of clog particles and the changes in permeability are observed. Efficiency of declogging methods like pressure washing and vacuum suction on PC with different sized aggregates are also evaluated.

Simulation of the hydraulic performance of highway filter drains through laboratory models and stormwater management tools

Road drainage is one of the most relevant assets in transport infrastructure due to its inherent influence on traffic management and road safety. Highway filter drains (HFDs), also known as "French Drains", are the main drainage system currently in use in the UK, throughout 7000km of its strategic road network. Despite being a widespread technique across the whole country, little research has been completed on their design considerations and their subsequent impact on their hydraulic performance, representing a gap in the field. Laboratory experiments have been proven to be a reliable indicator for the simulation of the hydraulic performance of stormwater best management practices (BMPs). In addition to this, stormwater management tools (SMT) have been preferentially chosen as a design tool for BMPs by practitioners from all over the world. In this context, this research aims to investigate the hydraulic performance of HFDs by comparing the results from laboratory simulation and two widely used SMT such as the US EPA's stormwater management model (SWMM) and MicroDrainage®. Statistical analyses were applied to a series of rainfall scenarios simulated, showing a high level of accuracy between the results obtained in laboratory and using SMT as indicated by the high and low values of the Nash-Sutcliffe and R 2 coefficients and root-mean-square error (RMSE) reached, which validated the usefulness of SMT to determine the hydraulic performance of HFDs.

Geographic information system-based assessment of mitigating flash-flood disaster from green roof systems

Urban flooding is a severe problem and a growing development challenge for many cities around the world. However, urban impervious areas have sharply increased owing to booming construction activities, and this land-use change leads to more frequent flood inundation in urban flood-prone areas. A green roof system is regarded as an effective mechanism to manage rainwater and reduce flooding disaster, as it is capable of retaining rainwater, thus reducing rainfall-runoff. There is still a lack of assessment of this stormwater management tool for flash floods. The issue of flood inundation associated with green roof systems needs to be explored and developed. To evaluate the effects of green roofs on urban flood inundation, this paper aims to construct a framework for modelling urban inundation integrating a hydrological model of green roofs. The approach addresses both urban rainfall-runoff and underground hydrological models for traditional impervious and green roofs. To accurately calculate the spatial variation, we have proposed a hydrological model to evaluate regional runoff on the basis of a catchment mesh. The Deakin University Waurn Ponds campus in Geelong was then chosen as a community-based study case. From geographic information system (GIS) simulation, the results reveal that the green roofs generated varying degrees of mitigation of urban flash floods with storms of different return periods.

Wet season hydrological performance of green roofs using native species under Mediterranean climate

Urban areas generate considerable amounts of stormwater runoff due to a high percentage of impervious surfaces. In Mediterranean climates, during winter, large volumes of rainfall over short periods of time can cause flooding. Green roofs are emerging as a tool for stormwater management under the Sustainable Urban Drainage Systems philosophy. This paper investigates the influence of rainfall patterns and types of native vegetation cover upon the rainfall-runoff relations of a green roof under a Mediterranean climate during the autumn/winter period. Test beds were installed on a rooftop in Lisbon, Portugal, incorporating a substrate layer 150mm deep, three native vegetation covers and one non-vegetated control. Rainfall and runoff data were monitored over a 6-month autumn/winter period. Results show that the vegetated systems reduced the stormwater runoff, attenuated peak flow and delayed runoff. Overall, 69 of 184 events did not produce runoff, median retention ranged from 55 to 100% and median peak attenuation from 97 to 100%. The combination of shrubs, grasses and mosses proved to be the most effective vegetation cover. Antecedent substrate moisture and plant rainfall interception significantly influenced green roof stormwater performance for all the vegetation covers. Estimations based on the experimental green roof data, an empirical model and a detailed spatial analysis, revealed that, by greening 75% of the flat roof area of the municipality of Lisbon, approximately 166 500–224 000m3 of water could be retained, relieving the drainage systems and preventing floods.

Measuring eco-roof mitigation on flash floods via GIS simulation

Purpose The rapid and ongoing expansion of urbanised impervious areas could lead to more frequent flood inundation in urban flood-prone regions. Nowadays, urban flood inundation induced by rainstorm is an expensive natural disaster in many countries. In order to reduce the flooding risk, eco-roof systems (or green roof systems) could be considered as an effective mechanism of mitigating flooding disasters through their rainwater retention capability. However, there is still a lack of examining the stormwater management tool. The purpose of this paper is to evaluate the effects on flooding disaster from extensive green roofs. Design/methodology/approach Based on geographical information system (GIS) simulation, this research presents a frame of assessing eco-roof impacts on urban flash floods. The approach addresses both urban rainfall-runoff and underground hydrologic models for traditional impervious and green roofs. Deakin University’s Geelong Waurn Ponds campus is chosen as a study case. GIS technologies are then utilised to visualise and analyse the effects on flood inundation from surface properties of building roofs. Findings The results reveal that the eco-roof systems generate varying degrees of mitigation of urban flood inundation with different return period storms. Originality/value Although the eco-roof technology is considered as an effective stormwater management tool, it is not commonly adopted and examined in urban floods. This study will bring benefits to urban planners for raising awareness of hazard impacts and to construction technicians for considering disaster mitigation via roof technologies. The approach proposed here could be used for the disaster mitigation in future urban planning.

Integrated design workflow and a new tool for urban rainwater management

Low Impact Development (LID) practices provide more sustainable solutions than traditional piping and storm ponds in stormwater management. However, architects are not equipped with the knowledge to perform runoff calculations at early design stage. In response to this dilemma, we have developed an open-source stormwater runoff evaluation and management tool, Rainwater+. It is seamlessly integrated into computer-aided design (CAD) software to receive instant estimate on the stormwater runoff volume of architecture and landscape designs. Designers can thereby develop appropriate rainwater management strategies based on local precipitation data, specific standards, site conditions and economic considerations. We employed Rainwater+ to conduct two case studies illustrating the importance of considering stormwater runoff in the early design stage. The first case study showed that integrating rainwater management into design modeling is critical for determining LID practice at any specific site. The second case study demonstrated the need of visualizing runoff flow direction in assisting the placement of LID practices at proper locations when the terrain is of great complexity.

Urban Stormwater Management Model and Tools for Designing Stormwater Management of Green Infrastructure Practices

Urbanization is growing rapidly in Malaysia. Rapid urbanization has known to have several negative impacts towards hydrological cycle due to decreasing of pervious area and deterioration of water quality in stormwater runoff. One of the negative impacts of urbanization is the congestion of the stormwater drainage system and this situation leading to flash flood problem and water quality degradation. There are many urban stormwater management softwares available in the market such as Storm Water Drainage System design and analysis program (DRAINS), Urban Drainage and Sewer Model (MOUSE), InfoWorks River Simulation (InfoWork RS), Hydrological Simulation Program-Fortran (HSPF), Distributed Routing Rainfall-Runoff Model (DR3M), Storm Water Management Model (SWMM), XP Storm Water Management Model (XPSWMM), MIKE-SWMM, Quality-Quantity Simulators (QQS), Storage, Treatment, Overflow, Runoff Model (STORM), and Hydrologic Engineering Centre-Hydrologic Modelling System (HEC-HMS). In this paper, we are going to discuss briefly about several softwares and their functionality, accessibility, characteristics and components in the quantity analysis of the hydrological design software and compare it with MSMA Design Aid and Database. Green Infrastructure (GI) is one of the main topics that has widely been discussed all over the world. Every development in the urban area is related to GI. GI can be defined as green area build in the develop area such as forest, park, wetland or floodway. The role of GI is to improve life standard such as water filtration or flood control. Among the twenty models that have been compared to MSMA SME, ten models were selected to conduct a comprehensive review for this study. These are known to be widely accepted by water resource researchers. These ten tools are further classified into three major categories as models that address the stormwater management ability of GI in terms of quantity and quality, models that have the capability of conducting the economic analysis of GI and models that can address both stormwater management and economic aspects together.

Building Water Sensitive Urban Design : Modelling of Green Roof

This project evaluates green roofs as a stormwater management tool. The goal of the project is to develop a computer aided stormwater model incorporating green roof, and evaluate its effectiveness. Specifically, the influence of media type, media depth, duration of rainfall event and average reoccurrence interval are investigated in design rainfall. The finalised model is then validated based on observed rainfall for the months of January and February of 2014. Results indicate that the green roofs are capable of removing 73.5% and 86.9% of the monthly rainfall volumes for January and February 2014, respectively, from a roof through retention. Water retention by green roofs effectively increases the time to reach the peak runoff, and slows the peak flows for a watershed. There are seasonal considerations as more runoff is generated during the month of January (northeast monsoon season) compared with the month of February (normal weather). Green roof is also effective in retaining 100% of several storms of less than 10 mm. The results demonstrate that the proposed extensive green roof for the study area functions as an excellent bio-retention system for stormwater control. The results of this research are in tandem with those of other researches performed throughout the world on hydrologic characteristics of green roof.

Verifying the Potential of New Online Stormwater Management Tools Through Test Marketing with the Development Community

Verifying the Potential of New Online Stormwater Management Tools Through Test Marketing with the Development Community

Hydrologic-Hydraulic Model for Simulating Dual Drainage and Flooding in Urban Areas: Application to a Catchment in the Metropolitan Area of Chicago

A one-dimensional (1D) hydrologic-hydraulic model for simulating dual drainage in urban areas is presented. It consists of four modules: (1) rainfall-runoff transformation, (2) 1D flow routing on a street network, (3) flow interception at street inlets, and (4) flow interaction between surface water on the streets and the underground storm-water system by interfacing with the EPA-SWMM5 engine (U.S. Environmental Protection Agency-Storm Water Management Model). The hydrologic model (first module) transforms rainfall to runoff using the kinematic wave approximation and simulates the infiltration process with the Green-Ampt method. The street network model (second module) is based on a finite-volume shock-capturing scheme that solves the fully conservative Saint-Venant equations and can be used to model both subcritical and supercritical flows. The inlet model (third module) computes the amount of water intercepted by inlets. The formulation of boundary conditions at the street crossings is generalized and can be used for any number of streets, any combination of inflowing and outflowing streets, and flow regime (e.g., subcritical and supercritical flows). Flow interaction between surface water on the streets and underground storm-water system is achieved by interfacing the proposed model with EPA-SWMM5. This interaction allows flow to enter from streets to the underground storm-water system and vice versa. The proposed model has several potential applications such as the identification of critical zones for flooding (e.g., zones with high water depths and flow velocities) in urban developments and can be used to take appropriate measures for drainage control (e.g., to increase number and/or size of inlets), to determine the consequences of different degrees of inlet clogging, and to assess flooding hazards through the application of suitable hazard criteria. A summary of criteria used for storm-water hazard assessment is presented. To demonstrate the dual-drainage model’s potential, an application is performed in a catchment of the metropolitan area of Chicago, Illinois. The results obtained are promising and show that the model can be a useful tool for storm-water management and flooding hazard assessment in urban areas.

The StormWater Management and Planning Tool: Coastal Water Quality Enhancement through the Use of an Internet-Based Geospatial Tool

Increasing development of coastal watersheds has altered groundwater and surface runoff patterns, and led to the progressive eutrophication of freshwater tributaries and adjacent coastal waters. Effective and properly engineered stormwater management systems represent one of the most important water resource protection strategies to counter this trend. Geospatial tools are needed to place existing and proposed development and stormwater management system (SWMS) infrastructure into a watershed context. A Geographic Information System (GIS) inventory of the existing SWMS infrastructure is a critical first step. To be most effective, this geospatial inventory, complemented by decision support tools, needs to be user friendly and readily available to a wide audience of target groups. To address this issue, we developed the StormWater Management Planning Tool (SWMPT) as a suite of on-line interactive mapping and query tools to facilitate access to data for display, assessment and analysis purposes needed for stormwater and sediment control. SWMPT is geared to meet the needs of municipalities and counties in planning and managing their SWMS infrastructure and has been implemented for Ocean County, NJ as a pilot project. To ensure that SWMPT met the needs of its identified target audience, a number of county and local partners and prospective end users were involved in the project from its inception through a highly structured design and evaluation process. The SWMPT interactive mapping tool can be accessed through www.BarnegatBayBasins.rutgers.edu.

Cementitious porous pavement in stormwater quality control: pH and alkalinity elevation

A certain level of alkalinity acts as a buffer and maintains the pH value in a stable range in water bodies. With rapid urban development, more and more acidic pollutants flow to watersheds with runoff and drop alkalinity to a very low level and ultimately degrade the water environment. Cementitious porous pavement is an effective tool for stormwater acidic neutralization. When stormwater infiltrates cement porous pavement (CPP) materials, alkalinity and pH will be elevated due to the basic characteristics of cement concrete. The elevated alkalinity will neutralize acids in water bodies and maintain the pH in a stable level as a buffer. It is expected that CPP materials still have a certain capability of alkalinity elevation after years of service, which is important for CPP as an effective tool for stormwater management. However, few previous studies have reported on how CPP structures would elevate runoff alkalinity and pH after being exposed to rainfall-runoff for years. In this study, three groups of CPP specimens, all exposed to rainfall-runoff for 3 years, were used to test the pH and alkalinity elevation properties. It was found that runoff pH values were elevated from 7.4 to the range of 7.8-8.6 after infiltrating through the uncoated specimens, and from 7.4 to 8.5-10.7 after infiltrating through aluminum-coated specimens. Runoff alkalinity elevation efficiencies are 11.5-14.5% for uncoated specimens and 42.2% for coated specimens. The study shows that CPP is an effective passive unit operation for stormwater acid neutralization in our built environment.

Structural Analysis of Pervious Concrete Pavement

Pervious concrete pavement must perform as both a stormwater management tool and a pavement. While much research has focused on porosity and permeability of pervious concrete, few guidelines exist for structural analysis and design of such pavement. In this paper, an existing pervious concrete pavement was analyzed for stiffness and fatigue by means of Westergaard's theory of a medium-thick plate on a Winkler foundation. The stiffness evaluation compared the responses of pervious and conventional concrete pavements to falling weight deflectometer stresses and to models created in ISLAB2005. Although pervious concrete had a lower modulus of elasticity than conventional concrete pavement, Wester-gaard's model adequately described the behavior of pervious pavements. Additionally, a fatigue analysis of pervious concrete was completed through use of the StreetPave fatigue model.

Integrated Water Quality Improvement Approach with Economic Consideration Using a Decision Support System and Application for Water Quality Design Storm Development

Integrated Water Quality Improvement Approach with Economic Consideration Using a Decision Support System and Application for Water Quality Design Storm DevelopmentAs an effective stormwater management tool implementing the integrated, watershed-based approach, the Los Angeles County Flood Control District has been developing the Watershed Management Modeling System (WMMS) for all of the County's 3,000-square mile coastal watersheds. Details of the hydrologic factors in the watershed have been represented in terms of rainfall variability, impervious cover...Author(s)Youn SimSourceProceedings of the Water Environment FederationSubjectSession 91: Challenges and Successes Implementing TMDLs in Southern California: A Critical Look at Essential Strategies and ApproachesDocument typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2011ISSN1938-6478SICI1938-6478(20110101)2011:9L.6083;1-DOI10.2175/193864711802766597Volume / Issue2011 / 9Content sourceWEFTECFirst / last page(s)6083 - 6093Copyright2011Word count376

Quantifying Evapotranspiration Rates for New Zealand Green Roofs

Green roofs are an emerging storm-water management tool that has predominantly been analyzed for runoff volume reduction and peak flow mitigation. Little research has been completed on evapotranspiration (ET) in green roofs. Sedum mexicanum (Mexican stonecrop) and Disphyma australe (New Zealand iceplant) in a New Zealand designed, pumice- and zeolite-based substrate were analyzed to determine daily and hourly ET rates under both water-abundant and drought-stressed conditions. Water loss, and thus storage recovery of the substrate, was greatest in the first 9 days. Transpiration (T) by S. mexicanum contributed up to 48% of total ET (2.19 mm/day) and D. australe contributed up to 47% of total ET (2.21 mm/day). After the initial rate of rapid water loss, plants conserved water and ET was not significantly different from evaporation (E) from unplanted substrate. S. mexicanum had a greater ability to conserve water and thus a greater longevity of life than D. australe under harsh drought conditions.

Effect of Coarse Aggregate on the Freeze-Thaw Durability of Pervious Concrete

Pervious concrete is becoming more common as a storm-water management tool in freeze-thaw climates. One of the main concerns or obstacles preventing a more widespread application is the aspect of freeze-thaw durability, whether perceived or actual. This paper describes a series of tests designed to determine the specific role coarse aggregate has on the freeze-thaw durability of pervious concrete using the ASTM C666A procedure. 17 different coarse aggregate samples were obtained from locations across the United States and Canada. Pervious concrete mixtures were placed using a mixture proportion previously determined as freeze-thaw durable. The range of durable aggregate gradations clearly defined a gradation specification and suggestions are made for optimizing the gradation with a small portion of sand. Mixtures with excellent freeze-thaw performance contained either granite or highly durable river gravel. The impact of aggregate angularity on mixture proportions and ultimate yield is also discussed.

Test Methods for Characterizing Air Void Systems in Portland Cement Pervious Concrete

Abstract Portland cement pervious concrete is becoming a common tool for stormwater management across the United States. The air void system in pervious concrete is particularly important because of its effect on stormwater infiltration, concrete strength, and long-term durability. However, currently the concrete industry lacks standardized testing techniques for characterizing air void systems in pervious concrete. In this paper a series of air system characterization tests performed during a field placement of pervious concrete is detailed, and the test results are compared. Fresh pervious concrete samples from two delivered mixtures were evaluated using pressure, volumetric, Chace, and air void analyzer air test methods. The hardened concrete samples were tested for water-permeable void content, water permeability, air voids (using ASTM Standard C457 method), and freeze-thaw durability (using ASTM Standard C666A method). Based on the results of the study, determination of air systems for the freeze-thaw protection of pervious concrete is proposed.