Low Impact Development Stormwater Management Research Articles

Assessment of low impact development stormwater management alternatives in the city of Bojnord, Iran

ABSTRACT This study addresses the stormwater management challenges and opportunities in the recently growing city of Bojnord in the northeast of Iran assessing six Low Impact Development (LID) stormwater management alternatives using hydrological, social and economic criteria through a questionnaire survey and modeling effort. Hydrological and economic effects were assessed using the SWMM model and cost analysis, respectively. Different LID alternatives were evaluated using six different multi-criteria decision-making (MCDM) approaches including TOPSIS, VICOR, SAW, MEW, ELECTRE III, and NFM. Due to differences in the ranking results of the MCDM methods, three aggregation methods of Rank average, Borda, and Copeland were used to reach consistency in the ranking. Rain barrel installation has been assessed as the most preferred LID alternative and the pervious asphalt as the least preferred one. The evaluation and ranking of the alternatives with MCDM approaches facilitated the effective prioritization of sustainable LID alternatives according to various management objectives.

Seasonal performance of field bioretention systems in retaining phosphorus in a cold climate: Influence of prolonged road salt application.

Bioretention systems are popular low impact development stormwater management features designed to remove pollutants, including phosphorus (P), from urban stormwater runoff. While the performance of bioretention systems in retaining P has been well studied, seasonal variability of P retention in field-scale systems installed in cold climates, including the influence of high road de-icing salt (sodium chloride) inputs, remains unclear. Two large field-scale bioretention systems installed in London, Ontario, Canada were monitored over their initial operational period to evaluate the seasonal trends in the retention of different forms of P in bioretention systems and the impact of high salt loading. Over the 12-month monitoring period, a net retention of total P and dissolved organic P, and a net release of soluble reactive P and total dissolved P mass were observed. Reduced hydrological performance and increased effluent P concentrations resulted in high P release from the bioretention systems in early to mid-spring (March and April), with most release occurring during a few individual large precipitation events. Laboratory-scale column experiments were performed using the engineered soil media installed in the field-scale bioretention systems to isolate the effect of high salt loading on P release. Column experiments combined with field data indicate that prolonged high salt loads through winter and spring may have contributed to elevated spring P release, mostly in the form of soluble reactive P, from the field-scale bioretention systems. Findings from this study are needed to better understand the performance of bioretention systems with respect to P retention as required to improve urban stormwater management in cold climates. Results have implications for further investigations of the impact of road salt on P mobility in bioretention systems and more broadly in roadside soils and groundwater systems.

Estimating Regionalized Planning Costs of Green Infrastructure and Low-Impact Development Stormwater Management Practices: Updates to the US Environmental Protection Agency's National Stormwater Calculator.

Estimating regional costs of green infrastructure (GI) and low-impact development (LID) stormwater management controls is an important issue for many municipalities and water utilities in the United States. The National Stormwater Calculator (NSWC) is a site-scale, planning-level tool. A regional cost estimation methodology was recently added to the NSWC, enabling users to estimate region-specific capital and maintenance costs of commonly used GI controls. This paper discusses the approach used to estimate and regionalize costs in the NSWC.

Cadmium removal from urban stormwater runoff via bioretention technology and effluent risk assessment for discharge to surface water

Bioretention technology, a low-impact development stormwater management measure, was evaluated for its ability to remove heavy metals (specifically cadmium, Cd) from urban stormwater runoff. Fine sand, zeolite, sand and quartz sand were selected as composite bioretention media. The effects of these materials on the removal efficiency, chemical forms, and accumulation and migration characteristics of Cd were examined in laboratory scale bioretention columns. Heretofore, few studies have examined the removal of Cd by bioretention. A five-step sequential extraction method, a single-contamination index method, and an empirical migration equation were used in the experiments. The average Cd removal efficiency of quartz sand approached 99%, and removal by the other media all exceeded 90%. The media types markedly affected the forms of Cd found in the columns as well as its vertical migration rate. The Cd accumulated in the four media was mainly in residual form; moreover, accumulation of Cd occurred mainly in the surface layer of the bioretention column. The migration depth of Cd in the four media increased with elapsed time, in the following sequence: zeolite>quartz sand>fine sand>sand. In contrast, the migration rate decreased with elapsed time, and the migration rate of Cd was lowest in sand (0.015m per annum over the first ten years). The comprehensive risk index analysis indicated that the risk arising from Cd discharge to surface water was “intermediate”, and that the degree of risk was lowest in sand, then quartz sand, zeolite, and fine sand in sequence. These results indicate that the adsorption and accumulation of Cd in the four media are more significant than the migration of Cd. In addition, the results of Cd risk assessment for the effluent indicate that each of the four media can serve as long-term adsorption material in a bioretention facility for purifying stormwater runoff.

Discussion of “Unsaturated Flow Functions for Filter Media Used in Low-Impact Development—Stormwater Management Systems” by Iulia A. Barbu and Thomas P. Ballestero

Discussion of “Unsaturated Flow Functions for Filter Media Used in Low-Impact Development—Stormwater Management Systems” by Iulia A. Barbu and Thomas P. Ballestero

Closure to “Unsaturated Flow Functions for Filter Media Used in Low-Impact Development—Stormwater Management Systems” by Iulia A. Barbu and Thomas P. Ballestero

Closure to “Unsaturated Flow Functions for Filter Media Used in Low-Impact Development—Stormwater Management Systems” by Iulia A. Barbu and Thomas P. Ballestero

Hydrological simulation approaches for BMPs and LID practices in highly urbanized area and development of hydrological performance indicator system

Urbanization causes hydrological change and increases stormwater runoff volumes, leading to flooding, erosion, and the degradation of instream ecosystem health. Best management practices (BMPs), like detention ponds and infiltration trenches, have been widely used to control flood runoff events for the past decade. However, low impact development (LID) options have been proposed as an alternative approach to better mimic the natural flow regime by using decentralized designs to control stormwater runoff at the source, rather than at a centralized location in the watershed. For highly urbanized areas, LID stormwater management practices such as bioretention cells and porous pavements can be used to retrofit existing infrastructure and reduce runoff volumes and peak flows. This paper describes a modeling approach to incorporate these LID practices and the two BMPs of detention ponds and infiltration trenches in an existing hydrological model to estimate the impacts of BMPs and LID practices on the surface runoff. The modeling approach has been used in a parking lot located in Lenexa, Kansas, USA, to predict hydrological performance of BMPs and LID practices. A performance indicator system including the flow duration curve, peak flow frequency exceedance curve, and runoff coefficient have been developed in an attempt to represent impacts of BMPs and LID practices on the entire spectrum of the runoff regime. Results demonstrate that use of these BMPs and LID practices leads to significant stormwater control for small rainfall events and less control for flood events.

Unsaturated Flow Functions for Filter Media Used in Low-Impact Development—Stormwater Management Systems

AbstractMoisture retention relationships for coarse, high-infiltration soils are difficult to empirically determine and estimate. Present day software models for stormwater management (SWM) that are used as sizing and performance prediction tools for filtration Low Impact Development-Stormwater Management (LID-SWM) systems typically assume that these systems function under saturated flow conditions. This directly impacts prediction of system drainage and hydrographs, as well as the estimates of physically-based water quality improvement. Yet real-time monitoring of these systems demonstrated that saturation of the filter media is rarely achieved. This article presents a framework for obtaining the moisture retention curves (MRC) and relative hydraulic conductivity Kr(θ) function for engineered filter media and other hydraulic control soils used in four LID-SWM systems: pervious pavement, sand filter, subsurface gravel wetland, and bioretention. These functions needed in routing water through the filter me...

Hydrologic Performance Monitoring of an Underdrained Low-Impact Development Storm-Water Management System

The use of low-impact development (LID) storm-water management facilities will grow with gains in understanding of their performance based on field tests. An innovative flow measurement system was designed and tested for monitoring of an interconnected system of underdrained LID components forming a site management strategy. Pressure transducers housed in stilling wells provided in-line flow measurements in pipes connecting the LID components. A combination of laboratory experiments, field measurements, and computer simulations was used to calibrate the flow measurement system to translate depth measurements to estimates of flow. The monitoring system is well suited for high-resolution temporal monitoring and provides important information for evaluating LID component performance. The measurement system is limited to open-channel flow, but calculations indicate that surcharge conditions are expected to occur at the case study site only under conditions more extreme than the 100-year storm event.