Urban Stormwater Management Systems Research Articles

Suitability of reclaimed asphalt pavement and recycled crushed brick as filter media in bioretention applications

Bioretention systems are increasingly being used in urban stormwater management systems, whereas quarry materials are used as filter media; however the use of quarry materials in this application reduces valuable natural resources. Such a novel approach of using recycled waste materials would significantly conserve valuable natural resources. A series of laboratory tests included particle size distribution, organic content, pH, specific gravity, flakiness index and hydraulic conductivity. Among the pollutants, total suspended solid (TSS), total phosphorus (TP) and total nitrogen (TN) were selected. A model for bioretention system was simulated to investigate the effectiveness of reclaimed asphalt material (RAP) and crushed brick (CB) materials in trapping selected pollutants. In terms of physical and chemical properties, RAP and CB were found to meet the stringent requirements of various environmental protection authorities. This research further indicates that recycled waste materials can be reused viably as alternative materials in bioretention systems.

Development of Simulation-Optimization Model (MUSIC-GA) for Urban Stormwater Management

Urban development leads to replacement of impervious surfaces with pervious surfaces, vegetation and production of various environmental pollutants. In addition, this phenomenon has increased the devastating effects of urban stormwater and has exacerbated the water quality of many freshwater resources (surface and underground) throughout the world. To alleviate this condition, new models of urban stormwater systems, including Water Sensitive Urban Design (WSUD) as well as its software package, MUSIC, have been developed. Regarding the water sensitive urban design, some urban stormwater treatment devices have been proposed and implemented to alleviate the effects of land use changes and improve the quality of downstream water. Although this new models provide cost-effective urban stormwater management methods, it is very challenging to determine an optimal mixture of various treatment devices and minimize the cost of urban stormwater control systems in this regard. Traditionally, the optimum and cost-effective urban stormwater treatment systems have been developed using simulation models such as MUSIC on the basis of trial and error. It should be noted that the latter models require considerable time to get close to an optimal solution. In this study, a simulation-optimization model of urban stormwater management system has been developed using a combination of MUSIC simulation model and Genetic Algorithm thereof. The simulation-optimization model (MUSIC-GA) greatly reduces the computation time and facilitates direct access to absolute optimal solution. The results of a case study on the application of the developed model in Australia have also shown that there have been some desirable convergences between the results of the simulation-optimization model and absolute optimal solution over various implementations of the model.

Engineering and Environmental Assessment of Recycled Construction and Demolition Materials Used with Geotextile for Permeable Pavements

This paper describes laboratory testing to investigate the suitability of recycled construction and demolition (C&D) materials as alternative subbase materials for permeable pavements. Permeable pavements are increasingly being used as urban stormwater management systems. Three commonly found recycled C&D waste materials, crushed brick (CB), recycled concrete aggregate (RCA), and reclaimed asphalt pavement (RAP), were investigated to assess their suitability as permeable pavement subbase materials. Geotextile was also used in this research to trap pollutants. The laboratory tests included basic physical characterization such as particle size distribution, specific gravity, water absorption, Los Angeles abrasion, California Bearing Ratio (CBR), and modified Proctor compaction tests. In addition, hydraulic conductivity tests were undertaken in a laboratory test setup with different influent suspension percentages and moisture contents. Temporal variations of effluent suspension percentages were investigated to assess clogging effects. It was found that the geotextile layer did not have any effect in terms of permeability of the C&D materials. The chemical assessment included organic content, pH value, trace element, and leachate concentration for a range of contaminant constituents and compared with maximum allowable limits in soil and natural water as well as with the environmental protection authorities' requirements. In terms of geotechnical and chemical assessment for permeable pavement applications, RCA was found to be a suitable alternative construction material for permeable pavements, while CB was borderline and RAP did not meet some of the specified requirements.

Climate Change Impact on Design Storm and Performance of Urban Storm-Water Management System - A Case Study on West Central Mountain Drainage Area in Canada

A number of future climate projections indicate a likelihood of increased magnitude and frequency of hydrological extremes for many regions around the world. The urban storm-water management infrastructures are designed to mitigate the effect of extreme hydrological events. Changes in extreme rainfall events will have a significant implication on the design of storm-water management infrastructures. This study assessed the potential impact of changed rainfall extreme on drainage systems in the West Central Mountain drainage area located in Southern Ontario, Canada. First, the design storms for the study area were calculated from observed rainfall data and the North American Regional Climate Change Assessment Program (NARCCAP) climate simulations based on SRES A2 Scenario. Frequency analysis was performed on the annual maximum time series data by using the best fitted distribution among twenty seven distributions. The Pearson chi-square test and Kolmogorov-Smirnov were used to test the goodness of fit of each distribution. The results show that L-moment Pareto distribution was selected the most often for data from six RCM+GCM pairs. Overall increase of storm depth in the future is highest when the distributions were identified by the Kolmogorov-Smirnov test. The design storm depths calculated from the observed and climate model simulated data were used as input into an existing PCSWMM model of the study area for flow simulation and hydraulic analysis for the storm-water management system, specifically storm sewer and detention pond. The results show an increase in design storm depths under projected climatic change scenarios that suggest an update of current standard for designing both the minor system and detention pond in the study area. The assessment results of storm water management infrastructures indicate that performance of the detention pond as well as the storm sewer network will deteriorate under future climate condition.

都市雨水管理システムの実時間制御におけるXバンド偏波レーダーによる降水予測情報の有効利用方策に関する研究

Urban flood problems have recently become severe, especially promoted by so-called guerrilla heavy rainfall, and water pollution problems in urban river derived from the non-point source also have continued since 1980s. Therefore, the urban stormwater storage system should be used more effectively in order to manage urban stormwater for both objectives. It requires the real time control of urban stormwater management system (RTCUMS) by using of rainfall forecasting information with some uncertainty. The latest high resolution X-band polarimetric RADAR system is expected to bring more effective control strategy for urban stormwater management. In this study, an available application strategy for RTCUMS is designed and evaluated under actual urban basin conditions.

Recycled construction and demolition materials in permeable pavement systems: geotechnical and hydraulic characteristics

Permeable pavements are increasingly being used as urban stormwater management systems. Permeable pavement systems enable stormwater to infiltrate through the pavement surface and into the filter layer. Three common recycled construction and demolition (CD crushed brick (CB), recycled concrete aggregate (RCA) and reclaimed asphalt pavement (RAP) were investigated in combination with nonwoven geotextile to assess their suitability as filter materials in permeable pavements. A series of laboratory tests was undertaken to assess the geotechnical and hydraulic characteristics of the CD however has potential to cause more clogging due to continuous accumulations of sediments in a long period. In terms of usage in permeable pavement filter layer, C&D materials were found to have geotechnical and hydraulic properties equivalent or superior to that of typical quarry granular materials. The Model for Urban Stormwater Improvement Conceptualisation (MUSIC) was furthermore employed to predict the pollutant removal efficiency of the C&D materials and the predicted results were validated with the laboratory experiments.

Application of Rainwater Garden in Economical Ecological Urban Landscape

With the acceleration of global sustainable development, the shortage of water resources especially the city has become the focus of attention in all countries since water is the key to build a resources-saving ecological city. The article improved the existing "rain garden" project and replenished the purification of the rain in order to realize the urban water cyclic utilization ,through recycling rainwater, which can manage rainstorm effectively , improve the urban water cycle system, as well as supply urban irrigation and underground water. Besides, the combination of urban landscape and stormwater management system, if widely accepted, will not only improve the urban water problem, but also improve the urban environment, alleviating the urban heat island effect and improving the local climate. It can shape a new resources-saving ecological city and then realize the sustainable development of resources.

The aesthetic performance of urban landscape-based stormwater management systems: a review of twenty projects in Northern Europe

Driven by the challenge of adapting cities to climate change, stormwater management is high on the agenda of landscape architectural practice. This article aims to set light on associated landscape changes, presenting and evaluating twenty Northern European stormwater management projects with a specific view on their aesthetic performance. Five key parameters form the base for the analysis. These include 1) terrain changes, 2) construction and maintenance, 3) site history and context, 4) water dynamics and dimensioning, and 5) stormwater accentuation. Observations are illustrated by exemplary photos, arranged and discussed among varying cases. The study indicates that visible stormwater management enhances the experience of local terrain. However, stormwater management is weak as a main design feature and staging water ‘at any cost’ results in unsettled designs. Successful projects include only a few key water features and focus on programmatic interaction within the specific context.

Enlightenment from ancient Chinese urban and rural stormwater management practices

Hundreds of years ago, the ancient Chinese implemented several outstanding projects to cope with the changing climate and violent floods. Some of these projects are still in use today. These projects evolved from the experience and knowledge accumulated through the long coexistence of people with nature. The concepts behind these ancient stormwater management practices, such as low-impact development and sustainable drainage systems, are similar to the technology applied in modern stormwater management. This paper presents the cases of the Hani Terrace in Yunnan and the Fushou drainage system of Ganzhou in Jiangxi. The ancient Chinese knowledge behind these cases is seen in the design concepts and the features of these projects. These features help us to understand better their applications in the contemporary environment. In today's more complex environment, integrating traditional and advanced philosophy with modern technologies is extremely useful in building urban and rural stormwater management systems in China.

Applying multi-criteria decision analysis to select WSUD and LID technologies

Water Sensitive Urban Design (WSUD) and Low Impact Development (LID) principles were investigated in Dhaka's drainage network using ‘Regime in Balance’ strategy for Average Recurrence Interval (ARI), Y = 100 years. Three feasible alternatives, such as, leaky-well, soak-away and infiltration trench were identified and designed to improve Dhaka's present unsatisfactory stormwater drainage system into one which is sustainable. For selecting the best one, we applied a multi-criteria decision analysis approach and chose the Analytic Hierarchy Process (AHP) model. Eleven criteria under three categories (technical, economic and social) were considered to quantify relative priorities of alternatives. Pair-wise comparisons of alternatives were performed against each criterion and ranked using a scale from 0 to 9. During the process of applying AHP model, consistency of ranking was thoroughly checked and a reasonable level of inconsistency was accepted due to the nature of human judgement. After the analysis, it was found that leaky-well (percentage priority 43%) followed by soak-away (38%) was the most appropriate technology for improving urban stormwater management system in Dhaka, Bangladesh. The proposed model can also be used in better selecting WSUD and LID technologies in other geographic locations.

A novel tracer technique for the assessment of fine sediment dynamics in urban water management systems

Urban storm water run off can reduce the quality of receiving waters due to high sediment load and associated sediment-bound contaminants. Consequently, urban water management systems, such as detention ponds, that both modify water quantity through storage and improve water quality through sediment retention are frequently-used best management practices. To manage such systems effectively and to improve their efficiency, there is a need to understand the dynamics (transport and settling) of sediment, and in particular the fine sediment fraction (<63 μm) and its associated contaminants within urban storm water management systems. This can be difficult to achieve, as modelling the transport behaviour of fine-grained and cohesive sediment is problematic and field-based measurements can be costly, time-consuming and unrepresentative. The aim of this study was to test the application of a novel cohesive sediment tracer and to determine fine sediment transport dynamics within a storm water detention pond. The cohesive sediment tracer used was a holmium labelled montmorillonite clay which flocculated and had similar size and settling velocity to the natural pond sediment it was intended to mimic. The tracer demonstrated that fine sediment was deposited across the entire pond, with the presence of reed beds and water depth being important factors for maximising sediment retention. The results of the sediment tracer experiment were in good agreement with those of a mathematical sediment transport model. Here, the deposited sediment tracer was sampled by collecting and analysing surface pond sediments for holmium. However, analysis and sampling of the three dimensional suspended tracer ‘cloud’ may provide more accurate information regarding internal pond sediment dynamics.

The spread of sustainable urban drainage systems for managing urban stormwater: A multi-level perspective analysis

Following the Brundtland Commission in 1987 (United Nation, 1987), numerous reports have condemned the impact of human activities on the environment, with the result that &#8220;sustainable development&#8221; has become a major issue for society. The move towards creating more sustainable cities, as described in the New Charter of Athens (ECTP, 2003), is a clear reflection of these concerns. The present article examines this final category of alternative techniques, focusing on urban stormwater management systems, which are designed to avoid the problems rainwater runoff can cause in urban environments, such as erosion of urban surfaces, floods, traffic disruption, and disruption to urban activities in general. More precisely, the barriers of uptake of innovation for sustainability in urban stormwater management systems are discussed.JEL Codes: Q01, Q25, R, L32, H75

Watershed Retrofit and Management Evaluation for Urban Stormwater Management Systems in North Carolina

Abstract:In response to water quality concerns in the Jordan Lake Reservoir and state and federal mandates, several cities in North Carolina are being required for the first time to reduce nutrient loads in stormwater from previously developed lands; that is, install retrofits. It is anticipated that similar requirements will become necessary for other urban areas in North Carolina. The goal of this study is to evaluate the feasibility of alternative approaches to stormwater management for existing developments within North Carolina cities. Geographic coverage of the study included a portion of the New Hope Creek watershed, located within the City of Durham in central North Carolina. The watershed was analyzed to identify potential retrofit opportunities that could be implemented to reduce pollutant loadings entering New Hope Creek and, ultimately, Jordan Lake. Current pollutant loadings generated by the watershed, as well as reductions in annual loadings of total suspended solids, total nitrogen and total phosphorus that could be achieved by implementing the identified retrofits, were estimated. Trends and relationships between land use type and the quantity and type of retrofit opportunities were identified and conclusions were drawn as to the most appropriate types of retrofits for certain land uses.

Sizing of Rainwater Storage Units for Green Building Applications

Green building design principles advocate the use of rainwater storage units to collect roof runoff during nonwinter seasons for landscaping, hardscape cleaning, and/or maintenance purposes, either in the form of rain barrels for smaller scale applications or cisterns for larger scale applications. This not only saves water which would otherwise be supplied from municipal water distribution systems but also reduces storm-water runoff which would otherwise be handled through urban storm-water management systems. The size of the storage units needs to be commensurate with the area of the roof and the desired water use rate. The local climate has an influence on the required size and achievable use rate as well. In this paper, analytical formulas are derived to estimate the required rainwater storage volume as a function of desired water use rate, reliability and local climate. In deriving these formulas, local climate characteristics are represented by probabilistic models and incorporated into the stochastic description of storage unit operating procedures and requirements. The resulting formulas may be used by engineers, architects, municipal governments, and storage unit manufactures for the estimation or recommendation of suitable rainwater storage unit sizes.

Understanding heavy metal and suspended solids relationships in urban stormwater using simulated rainfall

Urban stormwater from simulated rainfall on three different landuses in Queensland State, Australia (residential, industrial, commercial) was analysed for heavy metals and physico-chemical parameters such as Dissolved Organic Carbon (DOC) and Total Suspended Solids (TSS). Rainfall events were simulated using a specially designed rainfall simulator for paved surfaces. Event mean concentration samples were separated into five different particle sizes and analysed individually for eight metal elements (Zn, Fe, Cr, Cd, Cu, Al, Mn and Pb). Multivariate data analysis was carried out for the data thus generated. It was found that DOC and TSS influence the distribution of the metals in the different particle size classes. Zn was correlated with DOC at all three sites. Similarly, Pb, Fe and Al were correlated with TSS at all sites. The distribution of Cu was found to vary between the three sites, whilst Cd concentrations were too low to assess any relationships with other parameters. No correlation between Electrical Conductivity (EC), pH and heavy metals was found at the three sites. The identification of physico-chemical parameters influencing the distribution process kinetics of heavy metals in urban stormwater will significantly enhance the efficiency of urban stormwater management systems.

Urban drainage in developing countries – challenges and opportunities

Wastewater, the 'unwanted' water of a city, includes all types of domestic, commercial and industrial effluent as well as stormwater runoff during times of rainfall. This article highlights some of the challenges for urban planners and engineers in the design of effective urban drainage and stormwater management systems in developing countries.

The epidemiology of injuries in Atlanta day-care centers

The severity and frequency of short-duration, but damaging, urban area floods have increased in recent years across the world. Alteration to the urban micro-climate due to global climate change impacts may also exacerbate the situation in future. Sustainable urban stormwater management using low impact development (LID) techniques, along with conventional urban stormwater management systems, can be implemented to mitigate climate-change-induced flood impacts. In this study, the effectiveness of LIDs in the mitigation of urban flood are analyzed to identify their limitations. Further research on the success of these techniques in urban flood mitigation planning is also recommended. The results revealed that LIDs can be an efficient method for mitigating urban flood impacts. Most of the LID methods developed so far, however, are found to be effective only for small flood peaks. They also often fail due to non-optimization of the site-specific and time-varying climatic conditions. Major challenges include identification of the best LID practices for the region of interest, efficiency improvements in technical areas, and site-specific optimization of LID parameters. Improvements in these areas will allow better mitigation of climate-change-induced urban floods in a cost-effective manner and will also assist in the achievement of sustainable development goals for cities.