Stormwater Detention Systems Research Articles

FIELD DATA ANALYSIS OF HOME-BASED STORMWATER ON-SITE DETENTION SYSTEM

This paper describes the field test of a stormwater detention system which is a system designed to hold a specific volume of water and release it slowly over time, in this test case precast concrete modular units are assembled in a residential car porch and connected to a partial roof catchment via a downpipe. Stormwater is held and stored temporarily within the chambers created by the precast concrete pieces. Rainfall and flow data associated with the detention system in terms of the inflow, outflow and water levels data are collected and verification process are performed by comparing the collected data to design data for the intended system. Analyses of five storm events confirm that the estimated design inflow, outflow and water levels in response to 5- and 10-minute 10-year Average Recurrent Intervals (ARI) design rainfall are safe against the actual rainfall and actual detention and discharge performances.

Hydraulic retrofits can economically increase water and phosphorus retentions in end-of-the-farm stormwater systems

Aging agricultural stormwater detention systems (SDSs) are losing their ability to retain phosphorus (P) due to saturation. Soil P saturation leads to P retention being primarily dependent on water volume retention. The water quality and economic feasibility of hydraulic modifications were evaluated at an SDS in the Everglades basin. Modifications included compartmentalizing and increasing the retention volume by raising the discharge control elevation. Measurements showed increase in volumetric retention from 49% to 72% and P retention from 52% to 76%. Model simulations for a 25-year period showed that volume and P retentions could be as high as 92% with modifications, depending on the rainfall distribution. Economic analyses showed that modifications can provide additional water storage at $10/ac-ft ($81/ha-m) and P retention at $14/kg, which is more economical than the respective costs of 103/ac-ft ($835/ha-m) and $355-$909/kg P for the state-funded treatment systems. Basin-wide scale-up showed a potential reduction of 43,000 kg P per year. Modification costs are conservative since we assumed that additional water and P would be retained once every two years due to the occurrence of drier/wetter than normal years. Everglades is facing a multitude of challenges such as the timing and amounts of excess discharges of freshwater and P. We propose a payment for environmental services (PES) approach which lets the state choose the services depending on the specific challenges, such as excess water or P or both. Given the large-scale presence of SDSs or similar features globally, a public-private partnership to modify their hydraulic design can help achieve environmental goals, economically benefitting both the public (buyer) and private landowners (sellers).

EVALUATING THE EFFICIENCY OF HOUSEHOLD STORMWATER DETENTION SYSTEM

This paper describes the evaluation of water storing capacity of a household stormwater detention system based on field data. Collection of field data is often sidelined due to the cost and human capital incurred. However, the true value of field data is demonstrated here by comparing the observed and design data. A field test is completed in a real-life terrace house, utilizing the house’s 95m2 side canopy as roof catchment and 4.40m x 4.70m car porch area to station a detention tank. Precast concrete modular units with 3.9m3 effective storage volume are assembled within the tank. Downpipe with 0.1m diameter is installed to connect the roof gutter to the detention tank; while pipeline with 0.05m diameter is installed as the outlet from tank to the house perimeter drain. The mentioned setup is subjected to actual rainfalls from December 2019 till February 2020 that corresponded with the peak of Northeast Monsoon season. Ten observed storm events with peak hourly total rainfall readings ranging from 22 to 48mm are selected for analysis. Rainfall and water level readings from the field test allow the derivation of roof runoff volume and detained water volume in the tank. It is found that the household stormwater detention system is able to capture about 50% of the roof runoff. However, the current setup is found to cause flooding for rainfall over 40mm. The flooding issue, however, is undetected by the design data that underestimated the water storing capacity. This is due to the use of uncommon precast concrete modular units that may not have its flow characteristics represented by existing formula and model. No matter how uncommon the modular units be, various types and forms of stormwater detention system are becoming the new normal in the industry and field test is the best tool to validate their performances.

Case Study of Modular Pre-cast Concrete On-Site Stormwater Detention System during Monsoon Season in Southeast Asia

On-site stormwater detention system within a residential property is meant for an environmental protection device that temporarily stores stormwater within the property lot to mitigate flash flood, particularly during rainy seasons brought by the northeast monsoon. A field test was constructed in a house’s car porch with a 4.40 m x 4.70 m x 0.45 m tank filled with precast-concrete modular units with an effective storage volume of 3.97 m3. The system received water from a 95 m2 house roof via 0.1 m diameter pipe, discharged water via 0.05 m diameter pipe. It had recorded six observed storm events coincided with the 2019/2020 monsoon season that consisted 20–50 mm peak hourly rainfall, 0.0007–0.0018 m3 s-1 inflow, 0.0005–0.0012 m3 s-1 outflow and 0.21–0.47 m water level. Another four historical storm events coincided with the monsoon from 2015–2017 were sourced to augment the analysis. A computer model developed using the storm water management model was calibrated and verified using the six observed events. The Kolmogorov-Smirnov goodness of fit tests between the observed and modelled cumulative distributions had produced 0.01–0.14 maximum vertical distances that were lower than the 0.41–0.68 critical values indicating close matches. As such, the calibrated and verified model was used to simulate the historical storm events with 40–50 mm peak hourly rainfall and produced 0.0010–0.0013 m3 s-1 inflow, 0.00072–0.00076 m3 s-1 outflow and 0.41–0.45 m water level. By combining the field test and computer simulation model, it was found the system was able to contain all stormwaters from northeast monsoon. However, it had a weakness which the system was approaching its maximum capacity once the peak hourly rainfall exceeded 45 mm. With such a procedure in place, improvement could be carried out.

Catchment Size to Effective Tank Volume Relationships for Individual Lot Stormwater Detention System in Malaysian Detached House

Catchment Size to Effective Tank Volume Relationships for Individual Lot Stormwater Detention System in Malaysian Detached House

Valorization of farm pond biomass as fertilizer for reducing basin-scale phosphorus losses

Long-term fertilizer phosphorus (P) inputs are causing phosphorous saturation of agricultural soils globally. The saturation is spreading to the edge-of-the-farm stormwater detention systems (SDSs) from where the legacy P is potentially being released to downstream surface waters. We use site-specific and literature data for P-saturated SDSs, to develop and evaluate the biogeochemical and economic feasibility of a P recycling program that targets both low (LIC, sugarcane) and high intensity cropping (HIC, fresh-produce) systems within a watershed. The focus is to close the P cycle loop to rejuvenate P sink function of SDSs. It involves harvesting and composting the SDS's biomass and it's on-farm use as an organic fertilizer for crops. Results showed that harvesting-composting can conservatively increase the P retention from 50% to 77% for HIC and almost complete treatment for LIC. Beyond potentially increasing yield and improving soil health, compost use can further increase in-field retention of P (and water). Additional costs incurred in harvesting and composting can be offset by the economic value of compost and the reduction in State's expenditure on regional P treatment systems. Treatment costs were $26/kg of P for HIC and $42/kg for LIC, 10 times less than the current state expenditure of $355–$909/kg P using constructed wetlands. We propose an incentivized, payment for services (PS) program, where producers are paid for P recycling. The PS program considers the intensity of cropping systems and their location along the drainage network from headwaters to the outlet, to achieve basin-scale P load reduction. The LIC SDSs recover regional P by passing the public water through them while recycling is implemented at the HIC. The estimated basin-scale P retention with harvest-compost approach was 854 metric tons, 5 times the P that entered the Everglades Protection Area in 2018, at 88%–93% less cost than the State treatment systems.

Modelling of Compartmentalized Household Storm water Detention System using SWMM5

Modelling of Compartmentalized Household Storm water Detention System using SWMM5

Using nocturnal water level fluctuations for estimating seepage from stormwater detention systems

AbstractA simple method, modified from White's method, was developed and verified for estimating seepage from two stormwater detention areas (SDAs) for 2 years, using night‐time changes in surface water levels. The SDAs were located in warm sub‐tropical Florida where the assumption of negligible night‐time evaporation for White's method does not hold true. Daily seepage was estimated using the nocturnal water level fluctuations on no flow days during winter when evaporation losses were insignificant. Specific yield, rather than the composite specific yield, provided accurate seepage estimates. The average annual seepage from the two SDAs was 2.03 m/year. At almost 70% of surface flows, seepage is a significant contributor to regional surface and sub‐surface flows. Comparison of seepage estimates from the night‐time method (NM) and the water balance (WB) method showed that the NM‐based estimates were within the range of the estimates from the WB method. At SDA1, the differences between the NM and WB estimates were 1% and 11%, for the 2 years. The discrepancy between the two estimates became higher (27% and 23%) at SDA2. Larger differences at SDA2 were because of higher error in quantifying pumped inflows for the WB method. Successful performance of NM combined with its low resource (single well monitoring) requirements will help quantify seepage from detention areas and other similar features (e.g. ponds, constructed wetlands) in warmer climates. A scale‐up for the Caloosahatchee River basin showed that seepage from SDA's accounted for 15% of annual river flows indicating the importance of seepage in evaluating water and chemical balances. Copyright © 2015 John Wiley & Sons, Ltd.

Thermal Reduction by an Underground Storm-Water Detention System

Increases in stream temperatures by heated storm-water runoff from impervious surfaces are a serious environmental problem. An underground detention with slow-release facility is a versatile storm-water best management practice (BMP) for buffering high flows. Temperature reductions in underground storm-water storage BMPs, however, have not been quantified. A field study on an underground detention BMP located in Maryland was undertaken to characterize its effect on storm-water runoff temperatures. In colder months, when the runoff temperature ranged from 5 to 15°C , small or no temperature change was observed. Runoff produced during summer storm events, however, with event mean temperatures over 20°C , exhibited mean temperature reductions of 1.6°C through the BMP. While statistically significant, the reductions were not sufficient to cool the summer runoff discharges below the Maryland Class III temperature standard ( 20°C ) 100% of the time. The results indicate that underground facilities can moderate ...

Copper mobilization affected by weather conditions in a stormwater detention system receiving runoff waters from vineyard soils (Champagne, France)

Copper, a priority substance on the EU-Water Framework Directive list, is widely used to protect grapevines against fungus diseases. Many vineyards being located on steep slopes, large amounts of Cu could be discharged in downstream systems by runoff water. The efficiency of stormwater detention basins to retain copper in a vineyard catchment was estimated. Suspended solids, dissolved (Cu diss) and total Cu (Cu tot) concentrations were monitored in runoff water, upstream, into and downstream from a detention pond. Mean Cu tot concentrations in entering water was 53.6 μg/L whereas it never exceeded 2.4 μg/L in seepage. Cu tot concentrations in basin water (>100 μg/L in 24% of the samples) exceeded LC 50 values for several aquatic animals. Copper was principally sequestered by reduced compounds in the basin sediments (2/3 of Cu tot). Metal sequestration was reversible since sediment resuspension resulted in Cu remobilization. Wind velocity controlled resuspension, explained 70% of Cu diss variability and could help predicting Cu mobilization.

Assessing Storm Water Detention Systems Treating Road Runoff with an Artificial Neural Network Predicting Fecal Indicator Organisms

This paper examines whether multiple regression analysis and neural network models can be applied successfully for the indirect prediction of the runoff treatment performance with water quality indicator variables in an experimental storm water detention system rig. Five biologically mature experimental storm water detention systems with different designs treating concentrated gully pot liquor (spiked with dog droppings) were assessed. The systems were located on The King’s Buildings campus at The University of Edinburgh and were monitored for a period of 18 months. Multiple regression analyses indicated a relatively successful prediction of the biochemical oxygen demand and total suspended solids for most systems, but due to a relatively weak correlation between the predictors and both microbial indicators, multiple regression analyses were not applied for the prediction of intestinal enterococci and total coliform colony-forming units. However, artificial neural network models predicted microbial counts relatively well for most detention systems.

Evaluation of Mitigation Methods to Manage Contaminant Transfer in Urban Watersheds

Abstract Three case studies on trace metal contamination in urban stormwater are presented from the Greater Vancouver area of British Columbia. In the first case study, the spatial and temporal variability in trace metals in sediments were determined in the completely urbanized Brunette watershed. A natural lake in the middle of the watershed acts as a sediment detention system, and an analysis of the sediment core showed the historic accumulation of metal and selective organic contaminants in sediments since the early 1800s. Suspended sediments transported during storm events showed significantly higher concentrations of trace metals than bedload sediments, and the largest proportion of the geochemically active metals was found to be associated with the organic-sulphur-based fraction. Benthic organism survival tests showed mixed results with lower survival and growth in urban sediments than in control sediments from a forested watershed. In the second case study, significant correlations were obtained between percent impervious cover and trace metal concentrations in 28 subwatersheds with various degrees of urbanization. It is shown that imperviousness combined with traffic density can significantly improve the prediction of metal contamination in highly urbanized watersheds. In the third case study five urban stormwater detention systems were examined over one year to determine how effective these systems were in removing metal contamination. The results were highly variable depending on a wide range of physical conditions, land use activities, traffic volume, and detention system designs. The range of total metal detention was between −15 to +72% for copper (Cu), lead (Pb), and zinc (Zn), while iron (Fe) and manganese (Mn) retention was generally poor. Labile Zn was more effectively retained in four of the five ponds, and a significant relationship was found between percent imperviousness, traffic volume, and Zn concentrations in water, sediment, and labile form.

Design comparison of experimental storm water detention systems treating concentrated road runoff

The aim was to assess the treatment efficiencies of experimental storm water detention (extended storage) systems based on the Atlantis Water Management Limited detention cells receiving concentrated runoff that has been primarily treated by filtration with different inert aggregates. Randomly collected gully pot liquor was used in stead of road runoff. To test for a 'worst case scenario', the experimental system received higher volumes and pollutant concentrations in comparison to real detention systems under real (frequently longer but diluted) runoff events. Gravel (6 and 20 mm), sand (1.5 mm), Ecosoil (inert 2 mm aggregate provided by Atlantis Water Management Limited), block paving and turf were tested in terms of their influence on the water quality. Concentrations of five-day at 20 degrees C ATU biochemical oxygen demand (BOD) in contrast to suspended solids (SS) were frequently reduced to below international secondary wastewater treatment standards. The denitrification process was not completed. This resulted in higher outflow than inflow nitrate-nitrogen concentrations. An analysis of variance indicated that some systems were similar in terms of most of their treatment performance variables including BOD and SS. It follows that there is no advantage in using additional aggregates with high adsorption capacities in the primary treatment stage.

Structural Performance of Storm Water Detention System with Bundled High-Density Polyethylene Pipes

Buried parallel pipes are used for storm retention systems. Traditional retention-detention systems have spaced parallel pipes that permit soil columns between pipes. A new design allows for the parallel pipes to be placed side by side in contact with each other. The performance of such a system of bundled high-density polyethylene (HDPE) pipes that is subjected to vertical earth loads is reported. This bundled system consists of parallel HDPE pipes wrapped with a geogrid and a geofabric. The actual loads ranged from shallow cover to vertical loads equivalent to 55 ft (16.8 m) of cover. The embedment soil selected for the research was a silty sand. This soil was selected because its structural qualities are generally considered to be the least acceptable for these types of applications. The soil that typically would be specified is a crushed stone. Therefore, the results from the tests are conservative. Structural performance is reported, and photographs present the pipes in the bundled system during installation and after subjection to earth loads. Load-deflection curves for the pipes in the system are also given.

Hydrologic Mitigation Using On-Site Residential Storm-Water Detention

On-site storm-water detention systems can be used to mitigate the hydrologic effects of residential development and to provide a supplemental water supply at the scale of single residences. A three-year rainfall record from a site in the Puget lowland, Washington state, is used in a simple mass-balance model to simulate outflow from single- and multiple-purpose detention systems. Simulations are compared to time series of measured runoff from Evans Creek, a 37 km2, rural basis, and a 0.37 km2, zero-order forested subbasin. Discharge from a small on-site reservoir is sensitive to both the storage capacity and maximum controlled release rate of the system for extreme high flows (those exceeded 1% of the time) and low flows (those exceeded 80% of the time). An intermediate range of discharges (those exceeded 10–30% of the time) is primarily sensitive to release rate, rather than its storage capacity, suggesting that single-purpose systems with small reservoirs can be effective for hydrologic mitigation over ...

Tracking pollutant detention in constructed stormwater wetlands

The detention of stormwater in constructed ponds and wetlands is a widely adopted means of improving the quality of stormwater. The effectiveness of these detention systems in the removal of suspended solids and associated pollutants from stormwater is related to a number of factors, many of which are influenced by the detention period of pollutants. Stormwater detention systems operate over a wide range of hydrodynamic and pollutant loading conditions owing to the stochastic characteristics of stormwater quantity and quality. Stormwater pollutant detention periods vary according to the system hydrology (e.g. inflow characteristics and antecedent storage conditions) and the characteristics of the pollutographs. This paper presents a methodology and two case studies of a research project directed at tracking pollutant detention in basins controlled by two different outlet structures and a range of inflow characteristics. The results of the simulations provide an interesting insight on the influence of the types of outlet structures and stormwater inflow characteristics on the distribution of pollutant detention times.

Multiobjective Watershed-Level Planning of Storm Water Detention Systems

Detention basins are the most popular structural measure for urban flood control and have proven effective for both water quantity and quality management. Integrated, watershed-level planning of the layout and sizing of detention systems is essential because localized solutions may actually aggravate the negative impacts of urban drainage. Successive reaching dynamic programming (SRDP) is applied to minimize detention system costs of maintaining ranges of desired downstream peak flow attenuation, with basin and channel routing imbedded within the algorithm. A multiobjective genetic algorithm (MOGA) is also applied to generating nondominated solutions for system cost and detention effect for a watershed-level detention system. These algorithms are applied to a layout and design of a stormwater detention system in the Pazam watershed located in southern Taiwan. The case study confirms the robustness and computational efficiency of the SRDP algorithm, and the MOGA generates a wide range of nondominated solutions for trade-off analysis using a proposed \Ielite solutions conservation\N procedure.

On Integrating Continous Simulation and Statistical Methods for Evaluating Urban Stormwater Systems

The purpose of this chapter is to discuss various approaches for estimating the pollutant removal by urban stormwater detention systems. After a brief descript…

On-site stormwater detention systems in Sydney

On-site stormwater detention (OSD) requirements are applied by most municipalities in Sydney, Australia. Persons redeveloping properties served by existing drainage systems must provide storages for stormwater, to compensate for increased runoff from the new development. While OSD is widely accepted, procedures differ considerably between municipalities. Many designers criticise guidelines and design methods, and express doubts about the maintenance and economy of OSD systems. This paper surveys the application of OSD in Sydney, describes typical installations, and reviews their effectiveness. It sets out the main arguments for and against OSD systems, discusses alternatives, and indicates how systems and procedures will evolve in the future.

On-site stormwater detention systems in Sydney

On-site stormwater detention (OSD) requirements are applied by most municipalities in Sydney, Australia. Persons redeveloping properties served by existing drainage systems must provide storages for stormwater, to compensate for increased runoff from the new development. While OSD is widely accepted, procedures differ considerably between municipalities. Many designers criticise guidelines and design methods, and express doubts about the maintenance and economy of OSD systems. This paper surveys the application of OSD in Sydney, describes typical installations, and reviews their effectiveness. It sets out the main arguments for and against OSD systems, discusses alternatives, and indicates how systems and procedures will evolve in the future.Le stockage à la parcelle des eaux de pluie (on-site stormwater detention, OSD) est appliqué par plusieurs municipalités autour de Sydney, Australie. Quand quel-qu'un souhaite réaménager des terrains préalablement drainés par on système existent d'assaissement, il doit installer des réservoirs de stockage destinés à compenser l'augmentation du ruissellement dû à l'évolution de l'urbanisation. Bien quo la stockage à la parcelle des eaux de pluie soit généralment bien accepté, leg procédures utilisées différent sensiblement selon leg municipalités. Beaucoup d'ingénieurs critiquent les norms et les méthodes de conception, et expriment des doutes relatifs aux coûts et aux difficultés d'entretien de ces systèmes. Cet article étudie les modalités d'applicadon des systémes de stockage à la parcelle à Sydney; it décrit en particuller leg différents types d'installations et analyse leur efficacité. Il discute leg avantages et leg inconvénients du stockage à la parcelle, présente leg différentes alternatives et tente de prévoir comment leg systémes et leg procédures vont se développer thing l'avenir.