Stormwater Detention Facilities Research Articles

Planning and Design Strategies for Green Stormwater Infrastructure from an Urban Design Perspective

With the rapid advancement of ecological civilization construction, prioritizing green stormwater infrastructure to address urban stormwater management issues has become an important strategy for ecological priority and green development in sustainable urban development. Green stormwater infrastructure, as a major facility in the construction of sponge cities, can reduce the generation and external discharge of runoff and play a purification role. However, there are various types of green stormwater infrastructure, each with different control effects and applicable conditions. Therefore, to facilitate the planning, design, acceptance, assessment, and monitoring evaluation of sponge city green stormwater infrastructure, this study proposes the “sponge equivalent” method. By comparing the control effects of different facilities with bioretention facilities, the method standardizes the effects, making them easier to understand and apply. Taking a typical area of Beijing and its urban roads as examples, the study analyzed and applied planning and design control strategies. The results show that for a residential area of 1 km2, to achieve the annual runoff total control rate target of 85%, the method of converting runoff volume control equivalents, using bioretention pools as a benchmark, allows for the calculation of various combinations of areas of different types of green stormwater infrastructure, such as sunken green spaces, permeable paving bricks, green roofs, and water storage tanks. This optimizes the planning index of Beijing, which mandates stormwater detention facilities for new projects with a hardened surface area of 2000 m2 or more. The sponge equivalent method can optimize the planning and design control strategy of green stormwater infrastructure, allowing for rapid assessment and application of the design scale of green stormwater infrastructure in areas during the planning and design stage, providing theoretical and technical support for ecological and green urban stormwater management. The application of this research method helps promote green development and ecological priority in urban sustainable development strategies, and the conclusions provide valuable references for decision-makers and practitioners in related fields.

Role of Hydrodynamic Forces in Shaping the Dynamics of Channel Evolution in Urban Watershed

This study explores the impact of urbanization on stream channel erosion. The effect of changes in flow regimes and the associated changes in hydrodynamic forces were studied using monitored data for nine outfalls in Fairfax County, Virginia. The Stormwater Management Model (SWMM) simulated the flow and velocity hydrographs at each outfall site, using continuous rainfall records for the period 2004–2014. The cumulative stream flow work was used to study the impact of change in hydrology and hydraulics on the dynamics of channel evolution. The cumulative stream flow work at each section was determined by integrating the stream power (discharge time velocity) with time. The results show heterogeneity in the responses of the downstream channel reaches. However, the aggregation of results shows that the cumulative stream flow work accounts for about 70% of the variance in the observed changes in stream cross sectional areas. The cumulative stream flow work was suggested as a method for sizing stormwater detention facilities to meet the channel protection criteria for adequacy of outfalls. The advantage of the method is that it accounts for both the generated runoff at point of discharge and the connectivity of the site to the downstream watercourse. The study suggests that the channel protection criteria for adequacy of outfall should be based on limiting the post-developed cumulative stream flow work to its pre-developed conditions.

Reliability-Based Design of Urban Stormwater Detention Facilities with Random Carryover Storage

AbstractEvaluation of the operational efficiency of a stormwater detention facility may involve deterministic simulation or application of probabilistic models derived from runoff statistics. Using...

AI-based design of urban stormwater detention facilities accounting for carryover storage

Rapid urbanization in metropolitan areas easily triggers flashy floods. Urban drainage systems conveying stormwater out of cities are key infrastructure elements for flood mitigation. This study develops an intelligent urban flood drainage system accounting for carryover storage through optimizing the multi-objective operation rules of pumping stations for effectual flood management in Taipei City. The Yu-Cheng pumping station constitutes the study case, and a large number of datasets collected from 17 typhoon/storm events are adopted for model construction and validation. Three objective functions are designed to minimize: (1) the sum of water level fluctuations in the flood storage pond (FSP); (2) the sum of peak FSP water levels; and (3) the mean absolute difference of pump switches between two consecutive times along operation sequence. The non-dominated sorting genetic algorithm II (NSGA-II) is applied to searching the Pareto-optimal solutions that optimize the trade-off between the objectives. We next formulate the optimal operation rules through a two-tier sorting process based on a compromised Pareto-optimal solution. The comparison of the simulated results obtained from both the optimal operation rules and current operation rules indicate that the optimal operation rules outperform current operation rules for all three objectives, with improvement rates reaching 43% (OBJ1), 3% (OBJ2) and 71% (OBJ3), respectively. We demonstrate that the derived intelligent urban flood drainage system can serve as reliable and efficient operational strategies for urban flood management and flood risk mitigation.

Probabilistic modeling of the efficiency of a stormwater detention facility

In modern urban drainage systems, stormwater detention facilities are important tools to reduce flood effects and discharges of uncontrolled pollutants into water receivers. For their design, simplified methods and continuous simulations of observed data are generally used. One of the main targets is to limit the frequency and the entity of overflows. In this article, a probabilistic approach for the derivation of the distribution functions of spilled volumes to evaluate the efficiency of a stormwater detention facility is proposed. The possibility of pre-filling of the storage capacity from a previous rainfall event, which can increase the probability of overflows from the stormwater detention facility, has been considered. The effects of the simplified assumptions have been deeply investigated and discussed. Final expressions have been applied to a case study, and results have been compared to those obtained from the continuous simulation.

Probabilistic Analysis of the Retention Time in Stormwater Detention Facilities

Stormwater detention facilities are often used in modern drainage systems to reduce the hydraulic load on existing sewers, due to the increase of impermeable surfaces and to the more frequent extreme rainfalls, consequence of climate changes. Although their design is mainly aimed to limit uncontrolled spills into receiving water bodies, storage capacity for water quality enhancement is often considered, mainly with the purpose of increasing the retention time. Standard analysis is usually based on empirical methods or on continuous simulations. This paper focuses on the probabilistic analysis of retention times aimed to provide guidance to engineers for the design of stormwater detention facilities. In particular, the influence on retention time of the possibility of water mixing from consecutive rainfall events, due to the pre-filling of the storage capacity from previous runoffs has been investigated. Derived expression has been tested by their application to a case study.

Revised design criteria for stormwater facilities to meet pollution reduction and flow control requirements, also considering predicted climate effects

There is a need to revise existing design methods for stormwater pollutant treatment, flow transport and detention facilities. The aim is to increase the accuracy in predicting the performance compared with design only based upon areal and volumetric functions and to optimize design by considering more site-specific data, receiving water quality criteria and forecasted climate effects. During the latest years, flow proportional concentration data from in- and outlets from wet ponds and constructed wetlands, have been compiled. Furthermore, other kind of data from the specific facilities have been compiled, such as areas, volumes, proportion of vegetation, outlet design details and length:width ratio. The parameters are used to revise design methods and are implemented in the operative stormwater and recipient software model StormTac. Design criteria and parameters for calculating design flow and sizing required detention volume are also presented. The climate effects on some of the studied parameters, e.g. design flow and inlet concentration, are discussed. The paper presents the climate factor based upon the hypothesis that it is a function of the design rain duration and reoccurrence time.

Stormwater Pond Sediment Loading and Accumulation Analysis

The permanent pool in stormwater detention facilities is designed for water quality treatment by providing an appropriate storage volume for the settling of th…

지구내 저류시설의 유출저감효과 정량화 및 적정용량 결정

본 연구에서는 시가지 유역에서 이용 가능한 지구내 저류시설의 유출저감효과를 정량화하였으며, 저류시설 가용지를 대상으로 적정 설계용량을 산정해보았다. 대상 시설에 대한 유출모의를 위해 수정합리식을 이용하였으며, 유출저감효과는 집수면의 토지 피복 특성, 강우특성, 저류시설의 규모별로 정리하였다. 아울러 기성시가지 유역에서 적용 가능한 지구내 저류시설 지역을 조사하였으며, 시설물 설치시 적정 설계규모를 결정하였다. 본 연구의 결과는 기성시가지의 제한된 여건 속에서 침수재해 저감을 목적으로 지구내 저류시설을 고려할 경우, 예상되는 유출저감효과를 간단히 파악할 수 있을 뿐만 아니라 적정 설계규모를 결정하는데 이용될 수 있을 것이다. The purpose of this study is to quantify the runoff reduction effects of on-site stormwater detention facilities in urban area, and to determine the optimal size of storage capacity. The modified rational equation was used to calculate the hydrograph into detention facilities. The storage effect by the facilities was estimated with respect to rainfall characteristics, land cover type, and facility sizes. Also, the optimal storage volume and the condition of location of on-site stormwater detention facilities analyzed through field survey in a case study area. This study results could be helpful to easily understand the flood reduction effect, and to determine the optimal capacity when designing on-site stormwater detention facilities in built-up areas.

Stormwater Pond Sediment Loading and Accumulation Analysis Using Continuous Simulation

Stormwater Pond Sediment Loading and Accumulation Analysis Using Continuous SimulationThe permanent pool in stormwater detention facilities is designed for water quality treatment by providing an appropriate storage volume for the settling of suspended solids and particulate matter that is carried in stormwater runoff. Sizing of the permanent pool volume is often based on local regulatory requirements that dictate a prescribed Total Suspended Solids (TSS) removal rate, expressed as...Author(s)Mike GregorySourceProceedings of the Water Environment FederationDocument typeConference PaperPublisherWater Environment FederationPrint publication date Oct, 2013ISSN1938-6478DOI10.2175/193864713813668169Volume / Issue2013 / 18Content sourceWEFTECCopyright2013Word count167

New Method for Modeling Thin-Walled Orifice Flow under Partially Submerged Conditions

AbstractOrifices are often used in stormwater detention facilities for reducing runoff peak flow and achieving extended detention times to improve water quality. Orifices often flow partially full; therefore, accurate and easily implemented methods of modeling basin outflow under such conditions are needed. In this paper we describe two models of partially submerged flow in thin-walled orifices and conduct full-scale testing of these models. The best model (termed the top-width weir approach) treats the orifice as an equivalently sized rectangular weir, where the equivalent weir length equals the top width of flow in the orifice until half-full and the diameter of the orifice when greater than half-full. A single fitting coefficient Cw is required, which is directly proportional to the discharge coefficient for submerged orifice flow. This method provides results that, except for low submergence conditions, are within 2 to 5% of experimental data for steady flow, a significant improvement over the existin...

Compliance Rates for Storm Water Detention Facility Installation

Best management practices (BMPs) are designs and practices used to mitigate the environmental impacts of nonpoint source pollution, a leading cause of receiving water quality degradation in the United States. Proper selection and design of a BMP should consider its performance throughout its anticipated life. The magnitude of one particular life cycle variable, representing the likelihood of installation of a required storm water detention facility, was analyzed based on data from 716 privately developed sites in a county in South Carolina. This yielded an overall 86% probability for storm water detention facility construction. This variable was found to be approximately 79 and 88% for areas of disturbances of less than 0.4 ha and greater than 0.4 ha, respectively. Such compliance rates are useful information in conducting BMP life cycle analyses as well as for improving nonpoint source pollution estimates for postconstruction watershed conditions.

SIMULATION OF THE EFFECTS OF STRUCTURAL SCALE OF DETENTION FACILITIES ON FLOOD CONTROL

Stormwater detention facilities have been used to reduce flood runoff from urbanized areas. They are recognized as means to reduce peak flows of downstream rivers, and it is needed that the planning of them are done on a watershed-wide basis. In this paper a method to estimate the flood control effects of detention facilities on a watershed-wide basis, and the results of its application to Tsurumi river basin are presented. We could estimate the flood control effects of detention facilities by comparing the hydrographs calculated by the present method for Tsurumi river basin with and without detention basins respectively. It is found that there was little effect on flood control of the small scale detention facilities.

The influence of stormwater treatment on the hydraulic and pollution load – balance for an entire river basin

The installation of about 500 stormwater detention facilities (SDFs) led to a significant drop of the pollution originating from stormwater runoff in the river basin of the Ruhr which covers 4,488 km2. The German technical directives on the design of SDFs are briefly outlined and the specific costs for such plants are given. The average costs for one kilogram COD held back by SDFs in combined systems amount to Euro 3.73 (calculated without consideration of the subsequent removal in the municipal wastewater treatment plant (WWTP)). The tank volume for stormwater storage can be minimised by application of real-time management systems which allow a dynamic operation of all SDFs in a catchment area.

Vacuum-driven CSO detention tanks

The issue of how to increase the storage capacity of existing sewerage networks gained in recent times high national priority in Poland as well as in other countries of former Eastern Europe. An interesting and novel technology of constructing stormwater detention facilities using vacuum for enhanced evacuation of water from the tank developed by Polish scientists is presented. Technical description and comparison of traditional and vacuum-driven detention tanks is given. These solutions may constitute an efficient means of reducing the number of Combined sewer overflow occurrences and, consequently, reducing environmental pollution in any country.

Evaluation of a Combined Sewer Overflow Tank Cleaning System in the City of Sarnia

Abstract The International Joint Commission has identified the St. Clair River in Sarnia as an area of concern requiring a remedial action plan in order to restore and protect the water quality. To attain this objective, the City of Sarnia has completed a Pollution Control Plan in March 1993 to develop the approach in resolving the pollution problems along the City of Sarnia waterfront and the St. Clair River. The Pollution Control Plan identified the following three areas for improvement: (1) upgrade the water pollution control plant to provide secondary treatment for three times the average dry weather flow; (2) install four tanks to intercept combined sewer overflows; and (3) intercept storm runoff discharges along the waterfront and provide their treatment through sedimentation and/or flow through a wetland. The City of Sarnia is presently installing the first of the CSO control tanks at Devine Street. During the operation of combined sewage or stormwater detention facilities, settling of solids will occur along the invert of the facility. These sediments have to be removed after every storage event to minimize future problems such as caking and/or odour. This paper presents the evaluation and selection process carried out in developing a cost effective cleaning system for the Devine Street detention tank.

Optimal Estimation of Storage-Release Alternatives for Storm-Water Detention Systems

A heuristic optimization methodology is developed for obtaining the optimal allocation of storage capacity and release rate for the design of storm-water detention facilities. The nonlinear optimization procedure is formulated within the framework of production function theory. The model is set up in terms of a nonlinear cost-objective function with a technological production constraint, which is the storage/release isoquant defining runoff volume or pollutant load trap efficiencies. The process constraint is expressed as a function of the design variables of storage capacity and release rate, in terms of runoff process statistical parameters and desired trap efficiency. The analytical structure of the model allows the use of marginal analysis in obtaining the least cost solutions of storage capacity and release rate for any level of pollutant trap efficiency. It also allows prompt assessment of sensitivity, resiliency, and variability of pollutant loading rates. The methodology is applied to a catchment in Minneapolis.

Integrating Drainage, Water Quality, Wetlands, and Habitat in a Planned Community Development

This paper describes the planning, design, and construction of multiuse drainage facilities for the Rock Creek development, a planned residential community in the town of Superior, located between Denver and Boulder, Colorado. The Master Drainage Plan provides for a regional system of storm-water channels and detention facilities that provide management of the increased runoff due to urbanization and multiple use of the channels and ponds for open space, recreational greenway corridors, wetland preservation, and riparian habitat. Rock Creek is also the first community in Colorado to implement a comprehensive plan for quality enhancement of urban storm-water runoff. Under the plan, all storm flows from the development are routed through specially designed extended detention basins prior to discharge into the receiving drainageway. Selected stabilization measures are used along the channels to preserve their natural character and maintain stability.

Optimal design of runoff storage/release systems

An optimization methodology is developed for obtaining the optimal allocation of storage capacity and release rate for the design of storm water detention facilities. A trap efficiency expression for the detention unit relates process hydrologic variables with the design variables of total storage capacity and release rate. The optimization model, formulated within the framework of production function theory and marginal analysis, yields least cost combinations of storage capacity and release rate under the performance constraint of runoff or pollutant trap efficiency. The whole procedure is implemented in an electronic spreadsheet. The model is applied to a 640 acre catchment in Minneapolis, where a minimum cost earthen basin is designed for storing runoff to provide a uniform release rate to a sedimentation facility. The methodology provides an efficient table top procedure for identifying optimal solutions for a given set of process parameters. Sensitivity and resilience can be promptly assessed through a simple manipulation of input parameters.

Optimal design of runoff storage/release systems

An optimization methodology is developed for obtaining the optimal allocation of storage capacity and release rate for the design of storm water detention facilities. A trap efficiency expression for the detention unit relates process hydrologic variables with the design variables of total storage capacity and release rate. The optimization model, formulated within the framework of production function theory and marginal analysis, yields least cost combinations of storage capacity and release rate under the performance constraint of runoff or pollutant trap efficiency. The whole procedure is implemented in an electronic spreadsheet. The model is applied to a 640 acre catchment in Minneapolis, where a minimum cost earthen basin is designed for storing runoff to provide a uniform release rate to a sedimentation facility. The methodology provides an efficient table top procedure for identifying optimal solutions for a given set of process parameters. Sensitivity and resilience can be promptly assessed through a simple manipulation of input parameters.