Storm Drainage Systems Research Articles

DEM-based pluvial flood inundation modeling at a metropolitan scale

The global increase in urban flooding presents a substantial challenge that affects communities across the globe. This study introduces a post-flood inundation modeling framework tailored to pluvial floods on a metropolitan scale. We employ a dual drainage modeling approach for enhanced accuracy. The framework comprises two primary components: a Storm Water Management Model (SWMM) for simulating water movement within the storm drain system, and an advanced DEM-based flood inundation module that leverages SWMM results to predict flood inundation areas. Compared to the conventional flood spreading models commonly used in dual drainage modeling, this module incorporates high-resolution DEM cells into the surface flow routing processes, allowing to capture intricate surface terrain complexities. Additionally, the proposed module considers direct rainfall impacts on pluvial flood inundation mapping, resulting in enhanced accuracy. To evaluate the proposed model's accuracy, a two-step validation approach has been implemented. This includes comparing the proposed model results with both the high water marks measured in the aftermath of Hurricane Harvey and the flood depth map generated by a hydrodynamic model. The findings affirm the effectiveness of our proposed framework for post-flood inundation mapping within metropolitan settings. This method provides a dependable approach to urban flood modeling and represents an advancement in addressing the challenges associated with urban flooding.

Minimizing Urban Flooding by Optimal Design of Drainage System Using Sequential Least Squares Quadratic Programming and Spatial Datasets

Urban flooding is caused due to poor drainage design and excessive rain. It severely affects the road infrastructure. Existing hydrologic software tools to examine the extent of urban flooding primarily require walking through a series of manual steps and address each study area individually, preventing a collective review of poor storm-drains in an efficient manner. Previous methods for optimal drainage design were inefficient and lacked the ability of solving the underlying optimization problem due to the inherent nonlinearity of the decision variables. In this paper, we develop a nonlinear optimization formulation to minimize urban flooding using underground pipe size as a decision variable. We propose a solution algorithm using sequential least squares quadratic programming and spatial datasets. The proposed method eliminates the need to examine each study area manually using existing hydrologic tools. An example using the storm-drain system for the Baltimore County is performed. The results show that the model is effective in identifying storm-drain deficiencies and correcting them by choosing appropriate storm-drain inlet types to minimize flooding. Future works may include using large datasets and a more sophisticated modeling approach for estimating rainfall intensity based on extreme weather patterns. The method can be applied to other jurisdictions if relevant hydrological and underdrain piping network data were available.

Classification and description of the drainage state of manholes in urban drainage systems.

Manholes are important structures in urban storm drainage systems connecting roads and underground drainage networks, and they are also an important part of the research on improving urban resistance to storm flooding. Due to cost and space constraints, most of the existing experimental data on manholes come from scale model experiments obtained by scaling according to Froude's similarity criterion, and there is a lack of validation based on full-size experimental data. This also leads to inconsistencies in the form and parameter values of the manhole flow exchange equations derived from different experiments. To remedy this deficiency, a full-scale urban drainage engineering physics model was developed in this study with the aim of investigating the flow exchange of surface water as it flows through manholes into the sewer system. Experiments were conducted under steady flow conditions and compared with predictions from the existing models. The results show that the predictions of the existing model deviate significantly from the measured values when the flow is between free weir flow and submerged orifice flow. Therefore, we constructed a weighting equation based on weir and orifice flows and found that the weighting coefficients decayed exponentially during the transition from weir to orifice flow.

Distribution of pyrethroid insecticides in urban storm drain structures: Catch basins, open channels, and outfalls

Surface water runoff can transport contaminants offsite to downstream aquatic ecosystems. The prevalence of impervious surfaces in urban areas enhances surface runoff and contributes to contamination of urban surface streams. Urban areas have complex drainage systems for the conveyance of drainage water, however, there is a dearth of information on the distribution of contaminants within storm drain system structures. Pyrethroid insecticides are among the most used insecticides in urban areas, and trace levels of pyrethroids are known to exert toxicity to aquatic invertebrates. To investigate pyrethroid occurrence and distribution throughout an urban drainage system, samples of water, sediment, algae, and biofilm were collected from catch basins, open channels, and outfalls in Los Angeles County, California, during the dry season. From 3 catch basins, 7 open channels, and 7 outfalls, a total of 28 water samples, 4 sediment samples, 8 algae samples, and 4 biofilm samples were collected and analyzed. Pyrethroid concentrations above the reporting limit were detected in 89% of water samples and all sediment, algae, and biofilm samples, with bifenthrin and cyfluthrin being the most frequently detected compounds. The median total pyrethroid concentrations in water, sediments, algae, and biofilms were 27 ng/L, 88 ng/g, 356 ng/g, and 3556 ng/g, respectively. Bifenthrin concentrations in catch basins were found to be significantly higher than those in open channels or outfalls. Significant correlations were found for various metrics, including between pyrethroid partitioning in water samples and total suspended solids. These findings highlight the role of underground catch basins as a sink as well as a secondary source for contaminants such as pyrethroid insecticides. Prevention of the input of these urban originated contaminants to catch basins is crucial for protecting the water quality of urban surface waters.

Evaluating Compound Flooding Risks in Coastal Cities under Climate Change—The Maputo Case Study, in Mozambique

Flooding is a truly ubiquitous problem. Today, it puts an estimated 1.81 billion people at risk. Floods particularly affect coastal cities, where it is expected that the damage associated with inundations exceed the staggering value of USD 50 billion by 2050. Indeed, the risk associated with flooding in coastal cities is increasing due to three unequivocal trends: growing population in large urban centres, sea level rise, and increased intensity of extreme weather events. Planning and implementation of storm drainage systems in large cities is a complex, long, and expensive process. Typically, the effective lifespan of storm drainage systems may extend to nearly a century. Accordingly, such systems should be designed for the future, not the present. Addressing these important challenges, the paper evaluates flood risks in the coastal city of Maputo, in Mozambique. Results show that, although downtown Maputo is not particularly exposed to compound flooding, accounting for rainfall-tide events is essential to understand flooding in the area and evaluating the performance of the storm drainage system.

Comparative Activity And Efficacy of Sumilarv 0.5G and Altosid Xr Briquet Against Culex Quinquefasciatus and Aedes Aegypti in Simulated Catch Basins.

Mosquito control plays a crucial role in the mitigation of mosquito-borne diseases. Larviciding that targets one of the aquatic stages is among the routine practices in mosquito control operations. One of the most extensive and challenging mosquito production sources in urban environments is underground storm drain systems. Along with the research and development of biorational larvicides in recent decades, numerous products based on microbial and insect growth regulators have become available. However, the performance of these products often varies because of product design and challenges associated with urban storm drain systems. This paper validates the comparative bioactivity and semifield efficacy of 2 control release products based on pyriproxyfen and S-methoprene. In laboratory bioassays, pyriproxyfen was significantly more active than S-methoprene against the test species, Culex quinquefasciatus Say and Aedes aegypti (L.). Culex quinquefasciatus was less susceptible than Ae. aegypti to both test materials. During a 26-wk-long semifield evaluation using the cast concrete simulated catch basins, the inhibition of emergence pretreatment and posttreatment in untreated control was negligible. The Sumilarv 0.5G applied at 75 g per catch basin provided 100% IE, whereas the Altosid XR briquet applied at 1 per catch basin yielded only partial control fluctuating from 12.7% to 82.7% (average 40.7%) of Cx. quinquefasciatus and 8.0% to 78.8% (average 37.4%) of Ae. aegypti. The Altosid XR briquet had an average residual weight of 59.9% at the end of semifield evaluation. Results are discussed in relation to field mosquito control operations in urban storm drain systems.

Optimized strategies of green and grey infrastructures for integrated control objectives of runoff, waterlogging and WWDP in old storm drainages

Frequent waterlogging occurs in old high-density urban areas where the sewage is inappropriately connected to storm drainages, resulting in serious wet weather discharge pollution (WWDP). To address urban waterlogging and runoff, the optimization of green infrastructures (GIs) and grey infrastructures (GRs) has been proposed to improve rainwater management efficiency. However, most strategies neglect WWDP and fail to achieve integrated control of runoff, waterlogging, and discharge pollution. In the present study, a new optimization method was introduced to identify optimal solutions for renovating outdated storm drainage systems, considering the management of discharge pollution in wet weather. A case study in Shanghai, China was conducted to demonstrate the application of the method. The cost-benefit index (CBI) of optimized GIs (0.06) was lower than that of optimized GRs (2.78) under 22.2 mm rainfall (no runoff and WWDP), but the costs of the former were only half those of the latter. In a 5-year return period storm (no waterlogging), optimized GIs had a significantly higher CBI (2.85 times) compared to optimized GRs, costing only 44 % of the latter. When WWDP reached the control objective (COD≤70 mg/L), the optimized GIs needed to be further optimized with GRs. The CBI of optimized GI-GRs was higher than GRs by 2.50, and the cost was 58% of the latter. In areas with frequent low-intensity rainfall, optimized GIs and GRs should be selected based on local cost or benefit requirements for drainage reconstruction. In high-intensity storm-prone areas, the optimized GI-GR combination should be selected for drainage reconstruction. The proposed method can compensate for the shortcomings of existing optimization methods in controlling WWDP for the reconstruction of old storm drainages.

Enhancing the Vulnerability Assessment of Rainwater Pipe Networks: An Advanced Fuzzy Borda Combination Evaluation Approach

A vulnerability assessment system for rainwater pipe networks, comprising 13 indexes, was developed to facilitate the rational allocation and timely updating of urban storm drainage systems. An enhanced Borda combination evaluation method, which considers both the optimal and worst solutions, was proposed, accompanied by the operation procedure and numerical calculation method. Five stormwater systems in Central China were selected as case studies, and their vulnerability was evaluated and compared using five distinct evaluation methods: the entropy weight method, the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS), the efficacy coefficient method, the fuzzy comprehensive evaluation method, and the improved fuzzy Borda combination evaluation method. The results demonstrated that the correlation coefficients between the fuzzy Borda combination evaluation method and the four individual evaluation methods were equal to or greater than 0.88, indicating strong agreement. Additionally, the compatibility of the combination evaluation method was found to be 0.96. This study holds both theoretical significance and practical value for preventing urban waterlogging and contributes to the development of more resilient urban storm drainage systems.

Analysis of the Combination of the Soil Stability and the Slope Analysis Methods to Design a Retaining Wall on the Akoasa Mountain Mudslide (Accra, Ghana)

Purpose: The most unsafe geological chance in steep places is landslides. Landslides in Ghana have long been a most important source of worry, mainly during the rainy season. In some highland settlements, most of the buildings in Kasoa are impacted because the community is situated on a landslide terrain. Methodology: In this project, cantilever and relieving platform retaining walls with varied heights of 3 to 10 meters and SBC 160 KN/m2 were analyzed and designed. Additionally, a comparative of factors like cost, efficiency, bending moment, stability against overturning, and sliding between the two retaining walls are shown. The cost comparison is done together with the comparative analysis, and the lowest or best estimate is selected. Findings: This research also demonstrated that the relieving platform retaining wall is less expensive, more stable, and relieves the heel portion's bending moment Unique Contributions to Theory, Policy and Practice: To reduce the risk of landslides on the road or in the town as a whole, we plan to construct or design a retaining wall model and, if possible, add a storm drainage system to the project.

An AHP-TOWS Analysis of Options for Promoting Disaster Risk Reduction Infrastructure in Informal Settlements of Greater Giyani Local Municipality, South Africa

In the face of unstoppable urbanisation, disaster risks are projected to increase, mainly in unplanned areas that usually lack disaster risk reducing infrastructure. In Africa, including South Africa, limited resources and capacity hinder the provision of such infrastructure. The objective of this study was to determine options for promoting disaster risk reducing infrastructure in informal settlements in Giyani Municipality, Limpopo Province, South Africa, a disaster risk-prone area. A case study was conducted to collect primary data from purposively selected experts and the SWOT factors from the Integrated Development Plan Report of 2019/2020. A TOWS analytical hierarchical process was applied to pairwise comparisons of factors to prioritize them using eigenvalues and generate strategic options for promoting disaster risk reduction infrastructure in the informal settlements of Giyani Local Municipality. In the TOWS results, the experts suggested integrating traditional authorities into the municipal development processes, implementing an environmental framework that includes disaster management policies and an integrated waste management plan, and developing innovative technological projects that provide up-to-date spatial planning data to provide disaster risk reducing infrastructure in informal areas. This study concludes that the provision of affordable housing, clean regular piped water, storm and sewer drainage systems, street lighting, accessible routes, solid waste collection, electricity, and healthcare services would reduce a range of disaster risks.

Data analysis and integrated modeling of compound flooding impacts on coastal drainage infrastructure under a changing climate

Low-lying coastal areas are susceptible to multiple types of flooding from marine, subsurface, and surface sources. The co-occurrence of a rainfall event with high sea level, which raises coastal groundwater tables conjointly, may result in a compound flooding event, which could be much more widespread and dangerous than that of an individual flooding source. Focusing on Imperial Beach as a low-elevation coastal community in California, this paper provides a generalized methodology to determine the vulnerability of coastal stormdrain systems to compound seawater, groundwater, and stormwater flooding under a changing climate. Although marine inundation by itself is expected to flood only 7% of the study area by 2100 under the most pessimistic scenario (i.e. 2 m rise), our results show that more than 20% of the study area's subterranean stormdrain system is already at the risk of subsurface flooding at current sea levels. While marine inundation is a concern near the coastline as sea level rises, the results show that seawater intrusion into the stormdrain system can impact areas kilometers away from the coastline. The consequences of sea-level rise (SLR) can be exacerbated by an under-resourced stormdrain system, caused by groundwater infiltration through system defects. As such, by a 2 m rise in current sea-level, the flooding volume may double in an ideal system (i.e., no defects) while this ratio can increase six fold in a slightly defective stormdrain system (with 0.25 % porosity systemwide). The continuous simulations of the stormdrain system performance indicate that flood events will be more destructive and frequent under these circumstances.

Hydrologic Performance of Low Impact Developments in a Cold Climate

The application of the low impact development (LID) in a cold climate such as northeastern China is constrained by two unresolved research questions with regards to its infiltration potential through the winter and its varied runoff regimes between winters and summers. This study picked a typical residential district under construction in Changchun, China, and modeled the storm drainage system with and without LID facilities based on the Storm Water Management Model. The hydrological performance of LID was evaluated through various design storms and historic rain events in dry, average, and wet years. The influence of the Horton and the Green–Ampt infiltration methods on the seasonal water budgets was particularly compared since the former is universally adopted in China while the latter is more widely used in the U.S. and other countries. The results indicate that the Horton method tended to generate a higher infiltration volume than the Green–Ampt method. Consequently, when driven by the 100-year design storm, the Horton method led to a 17.4% higher outflow than the Green–Ampt method; when driven by the measured 3-year precipitation in the study area, the yearly runoff coefficients, with regards to the Horton method, were at least 1.3 times higher than those modeled by the Green–Ampt method. This finding challenged the interchangeable use of the Horton and Green–Ampt methods without tests. Furthermore, the formation of snow covers in winter also reduced the permeability of LID and its capacity of managing runoff compared to summer. However, LID still exhibited a decent potential of regulating the winter runoff in the cold region compared to the baseline, possibly owing to the presence of frequent freezing-thawing cycles.

Multisurrogate Assisted Evolutionary Algorithm–Based Optimal Operation of Drainage Facilities in Urban Storm Drainage Systems for Flood Mitigation

Multisurrogate Assisted Evolutionary Algorithm–Based Optimal Operation of Drainage Facilities in Urban Storm Drainage Systems for Flood Mitigation

Combined Optimization of LID Patches and the Gray Drainage System to Control Wet Weather Discharge Pollution

Low impact development (LID) has emerged as an effective management to control urban runoff. However, for storm drainage systems located in high-density old urban areas with scarce land resources and fragmented landscapes, there are difficulties in the application of LID layouts. To solve the waterlogging and wet weather discharge pollution (WWDP), based on the spatial distribution of available land resources, runoff path, ponding area, overflow nodes, and sediments in drainages, a spatial optimized layout method of LID patches combined with gray drainages was proposed and applied to a typical storm drainage system in Shanghai, China. Only 22.9% of the ground surface and 14.0% of the roof, which accounted for the study area were reconstructed to LIDs, and the optimal LID patches combined with 0.4 m storage capacity depth (SCD) could prevent discharge below 6.5 mm rainfall. The optimal LID-gray drainages increased the reduction ratios of suspended substances (SSs) in WWDP by 37–74% compared with only LID patches in 9.1–21.8 mm rainfall. The “LID patches-gray system” could effectively control WWDP in old urban areas with high frequencies of moderate and light rain. The proposed methodology can be instructive for the sustainable reconstruction of storm drainages inappropriately connected with sewage.

PROPOSED DRAINAGE SYSTEM AND STROM WATER MANAGEMENT STRATEGY

This paper focuses on the provision of drainage systems and stormwater management strategies at CT University. Although engineered infrastructure is a component for drainage of urban runoff, non-structural approaches are important complementary measures, focusing on actions to prevent and mitigate problems related to flooding as well as those related to pollution and deterioration in environmental health conditions. The following will be the analysis taken at CT University to provide solutions to the improper functioning of the drainage system. A participatory approach is recommended within a strategic framework of stormwater planning. Keywords: Storm Drainage system, storm water management, run off.

AUTONOMOUS ROBOTIC SYSTEMS FOR PIPE INSPECTION USING MAPPING AND NONDESTRUCTIVE TESTING

This paper presents the development of a mapping and nondestructive technique (NDT) for the assessment of concrete pipeline networks. It focuses on the inspection of open-end culverts and storm drain systems using sensor networks. The network consists of 3D Lidar/3D camera/radar with NDT sensors. These sensors are mounted on autonomous vehicles that are set to reduce the extent of human operator involvement through intelligent control algorithms. More accurate remote monitoring is achieved by using smart robots and sensor networks equipped with advanced AI-based techniques. In the systems, ground robots are used with onboard sensing to enable environmental observation. The ground robots have the capability of remote communication, teleoperation, and the transmission of collected data. Effective automated mapping requires the flexibility to allow real-time changes in planning to accommodate unmodeled/unexpected uncertainties and disturbances. The autonomous system can be used repeatedly with reduced cost, primarily for maintenance. In addition, making the process autonomous can reduce the risk to human inspectors and save time during inspections. Also, it can be operated by personnel who require less training to obtain the data than standard inspection processes. The developed technology is demonstrated by actual field and lab testing. It provides accurate assessment tools for underground pipeline networks.

AUTONOMOUS ROBOTIC SYSTEMS FOR PIPE INSPECTION USING MAPPING AND NONDESTRUCTIVE TESTING

This paper presents the development of a mapping and nondestructive technique (NDT) for the assessment of concrete pipeline networks. It focuses on the inspection of open-end culverts and storm drain systems using sensor networks. The network consists of 3D Lidar/3D camera/radar with NDT sensors. These sensors are mounted on autonomous vehicles that are set to reduce the extent of human operator involvement through intelligent control algorithms. More accurate remote monitoring is achieved by using smart robots and sensor networks equipped with advanced AI-based techniques. In the systems, ground robots are used with onboard sensing to enable environmental observation. The ground robots have the capability of remote communication, teleoperation, and the transmission of collected data. Effective automated mapping requires the flexibility to allow real-time changes in planning to accommodate unmodeled/unexpected uncertainties and disturbances. The autonomous system can be used repeatedly with reduced cost, primarily for maintenance. In addition, making the process autonomous can reduce the risk to human inspectors and save time during inspections. Also, it can be operated by personnel who require less training to obtain the data than standard inspection processes. The developed technology is demonstrated by actual field and lab testing. It provides accurate assessment tools for underground pipeline networks.

Modeling Sediment Load in Storm Drain System of Southeast Texas Coastal Region

Modeling Sediment Load in Storm Drain System of Southeast Texas Coastal Region

Pesticide concentrations in agricultural storm drainage inlets of a small Swiss catchment

Agricultural pesticides transported to surface waters pose a major risk for aquatic ecosystems. Modelling studies indicate that the inlets of agricultural storm drainage systems can considerably increase the connectivity of surface runoff and pesticides to surface waters. These model results have however not yet been validated with field measurements. In this study, we measured discharge and concentrations of 51 pesticides in four out of 158 storm drainage inlets of a small Swiss agricultural catchment (2.8 km2) and in the receiving stream. For this, we performed an event-triggered sampling during 19 rain events and collected plot-specific pesticide application data. Our results show that agricultural storm drainage inlets strongly influence surface runoff and pesticide transport in the study catchment. The concentrations of single pesticides in inlets amounted up to 62 µg/L. During some rain events, transport through single inlets caused more than 10% of the stream load of certain pesticides. An extrapolation to the entire catchment suggests that during selected events on average 30 to 70% of the load in the stream was transported through inlets. Pesticide applications on fields with surface runoff or spray drift potential to inlets led to increased concentrations in the corresponding inlets. Overall, this study corroborates the relevance of such inlets for pesticide transport by establishing a connectivity between fields and surface waters, and by their potential to deliver substantial pesticide loads to surface waters.

Assessing the Benefits of Nature-Based Solutions in a Storm Drainage System – a Case Study

<p>In most developing countries, stormwater drainage practice consists of a conventional storm drainage system designed to collect and convey excess runoff to the recipient as soon as possible, without any attenuation or peak flow decreasing effects. This paper aims to show the overall need for change in the urban drainage paradigm by showing the effects of reconstruction of the existing conventional stormwater drainage system into a new one by including green elements. Part of the existing system is replaced with vegetated swales, and two detention ponds are added in the common green areas (parks). Effects are analysed through a comparison of results from a mathematical rainfall-runoff model for the existing and reconstructed stormwater drainage system for both water quality and quantity at the sub-basin outlet point. The cost-effectiveness of the applied measures is quantified by comparing construction prices for the existing and the reconstructed system. The obtained results clearly show an urgent need for stormwater drainage practice improvement in countries where the conventional approach is still in use.</p>