Scenarios for redesigning an urban drainage system to reduce runoff frequency and restore stream ecological condition

2007 ◽  
Vol 2 (2) ◽  
Author(s):  
A. R. Ladson ◽  
S. Lloyd ◽  
C. J. Walsh ◽  
T. D. Fletcher ◽  
P. Horton

Monitoring the hydrochemical efficiency of urban stormwater treatment devices is not straightforward as the traditional, automated, In urban areas, efficient drainage of impervious surfaces means that polluted stormwater is frequently delivered to streams. Commonly, catchment urbanization can increase runoff frequency by a factor of 10 or more, as the effective imperviousness - the proportion of the catchment that consists of impervious surfaces drained to streams - is increased. This causes a decline in stream health. To decrease runoff frequency, effective imperviousness must be reduced. This requires urban drainage systems to be redesigned, using techniques such as infiltration and rainwater harvesting, so that stormwater from small rain events is not piped directly to streams but instead is infiltrated, reused or retained. We have developed scenarios that explore alternative urban drainage systems appropriate for a small partly urbanised catchment in Melbourne’s east. These scenarios incorporate, biofiltration basins, swales and dual purpose rainwater tanks that supply water for householders. Our results suggested that sufficient reductions in effective imperviousness and runoff frequency are possible to achieve improvements in stream health.

Sci ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 46
Author(s):  
Guri Venvik ◽  
Floris C. Boogaard

Sustainable urban drainage systems (SuDS) such as swales are designed to collect, store and infiltrate a large amount of surface runoff water during heavy rainfall. Stormwater is known to transport pollutants, such as particle-bound Potential Toxic Elements (PTE), which are known to often accumulate in the topsoil. A portable XRF instrument (pXRF) is used to provide in situ spatial characterization of soil pollutants, specifically lead (Pb), zink (Zn) and copper (Cu). The method uses pXRF measurements of PTE along profiles with set intervals (1 meter) to cover the swale with cross-sections, across the inlet, the deepest point and the outlet. Soil samples are collected, and the In-Situ measurements are verified by the results from laboratory analyses. Stormwater is here shown to be the transporting media for the pollutants, so it is of importance to investigate areas most prone to flooding and infiltration. This quick scan method is time and cost-efficient, easy to execute and the results are comparable to any known (inter)national threshold criteria for polluted soils. The results are of great importance for all stakeholders in cities that are involved in climate adaptation and implementing green infrastructure in urban areas. However, too little is still known about the long-term functioning of the soil-based SuDS facilities.


2009 ◽  
Vol 59 (6) ◽  
pp. 1137-1143 ◽  
Author(s):  
M. Möderl ◽  
D. Butler ◽  
W. Rauch

Typically, performance evaluation of new developed methodologies is based on one or more case studies. The investigation of multiple real world case studies is tedious and time consuming. Moreover extrapolating conclusions from individual investigations to a general basis is arguable and sometimes even wrong. In this article a stochastic approach is presented to evaluate new developed methodologies on a broader basis. For the approach the Matlab-tool “Case Study Generator” is developed which generates a variety of different virtual urban drainage systems automatically using boundary conditions e.g. length of urban drainage system, slope of catchment surface, etc. as input. The layout of the sewer system is based on an adapted Galton-Watson branching process. The sub catchments are allocated considering a digital terrain model. Sewer system components are designed according to standard values. In total, 10,000 different virtual case studies of urban drainage system are generated and simulated. Consequently, simulation results are evaluated using a performance indicator for surface flooding. Comparison between results of the virtual and two real world case studies indicates the promise of the method. The novelty of the approach is that it is possible to get more general conclusions in contrast to traditional evaluations with few case studies.


2017 ◽  
Vol 21 (3) ◽  
pp. 1559-1572 ◽  
Author(s):  
Nadav Peleg ◽  
Frank Blumensaat ◽  
Peter Molnar ◽  
Simone Fatichi ◽  
Paolo Burlando

Abstract. The performance of urban drainage systems is typically examined using hydrological and hydrodynamic models where rainfall input is uniformly distributed, i.e., derived from a single or very few rain gauges. When models are fed with a single uniformly distributed rainfall realization, the response of the urban drainage system to the rainfall variability remains unexplored. The goal of this study was to understand how climate variability and spatial rainfall variability, jointly or individually considered, affect the response of a calibrated hydrodynamic urban drainage model. A stochastic spatially distributed rainfall generator (STREAP – Space-Time Realizations of Areal Precipitation) was used to simulate many realizations of rainfall for a 30-year period, accounting for both climate variability and spatial rainfall variability. The generated rainfall ensemble was used as input into a calibrated hydrodynamic model (EPA SWMM – the US EPA's Storm Water Management Model) to simulate surface runoff and channel flow in a small urban catchment in the city of Lucerne, Switzerland. The variability of peak flows in response to rainfall of different return periods was evaluated at three different locations in the urban drainage network and partitioned among its sources. The main contribution to the total flow variability was found to originate from the natural climate variability (on average over 74 %). In addition, the relative contribution of the spatial rainfall variability to the total flow variability was found to increase with longer return periods. This suggests that while the use of spatially distributed rainfall data can supply valuable information for sewer network design (typically based on rainfall with return periods from 5 to 15 years), there is a more pronounced relevance when conducting flood risk assessments for larger return periods. The results show the importance of using multiple distributed rainfall realizations in urban hydrology studies to capture the total flow variability in the response of the urban drainage systems to heavy rainfall events.


2021 ◽  
Vol 13 (13) ◽  
pp. 7258
Author(s):  
Ana Isabel Abellán García ◽  
Noelia Cruz Pérez ◽  
Juan C. Santamarta

Sustainable urban drainage systems (SUDS), or urban green infrastructure for stormwater control, emerged for more sustainable management of runoff in cities and provide other benefits such as urban mitigation and adaptation to climate change. Research in Spain began a little over twenty years ago, which was later than in other European countries, and it began in a heterogeneous way, both in the SUDS typology and spatially within the peninsular geography. The main objective of this work has been to know through bibliographic review the state of the art of scientific research of these systems and their relationship with the different types of climates in the country. These structures have a complex and sensitive dependence on the climate, which in the Iberian Peninsula is mostly type B and C (according to the Köppen classification). This means little water availability for the vegetation of some SUDS, which can affect the performance of the technique. To date, for this work, research has focused mainly on green roofs, their capabilities as a sustainable construction tool, and the performance of different plant species used in these systems in arid climates. The next technique with the most real cases analyzed is permeable pavements in temperate climates, proving to be effective in reducing flows and runoff volumes. Other specific investigations have focused on the economic feasibility of installing rainwater harvesting systems for the laundry and the hydraulic performance of retention systems located specifically in the northeast of the Iberian Peninsula. On the contrary, few scientific articles have appeared that describe other SUDS with vegetation such as bioretention systems or green ditches, which are characteristic of sustainable cities, on which the weather can be a very limiting factor for their development.


Sci ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 34
Author(s):  
Guri Venvik ◽  
Floris C. Boogaard

Sustainable urban drainage systems (SuDS) such as swales are designed to collect, store and infiltrate a large amount of surface runoff water during heavy rainfall. Stormwater is known to transport pollutants, such as particle-bound Potential Toxic Elements (PTE), which are known to often accumulate in the topsoil. A portable XRF instrument (pXRF) is used to provide in situ spatial characterization of soil pollutants, specifically lead (Pb), zink (Zn) and copper (Cu). The method uses pXRF measurements of PTE along profiles with set intervals (1 m) to cover the swale with cross-sections, across the inlet, the deepest point and the outlet. Soil samples are collected, and the In-Situ measurements are verified by the results from laboratory analyses. Stormwater is here shown to be the transporting media for the pollutants, so it is of importance to investigate areas most prone to flooding and infiltration. This quick scan method is time and cost-efficient, easy to execute and the results are comparable to any known (inter)national threshold criteria for polluted soils. The results are of great importance for all stakeholders in cities that are involved in climate adaptation and implementing green infrastructure in urban areas. However, too little is still known about the long-term functioning of the soil-based SuDS facilities.


2009 ◽  
Vol 60 (7) ◽  
pp. 1919-1927 ◽  
Author(s):  
G. Vaes ◽  
T. Feyaerts ◽  
P. Swartenbroekx

Surface waters and urban drainage systems are usually studied separately. However there are important interactions between both systems. Urban drainage systems can have an important impact on the surface waters, mainly at combined sewer overflows. On the other hand during periods of high water levels in a river, the runoff from the urban drainage system can be significantly influenced by backwater, which increases the probability of flooding in is not obvious, because the modelling tools for both systems are often hard to combine properly. To properly assess the probability of flooding for this kind of integrated water systems, different submodels are needed for both subsystems. In practice often one single model is used to describe the runoff to rivers despite the presence of urban catchments. The main objective of this study is to show the limits of this simplified approach. Furthermore, it is necessary to use continuous long term simulations, because of the differences in runoff behaviour. Detailed hydrodynamic models do not really fit for this purpose because of long simulation times and high demands in memory and disk space. Therefore simplified conceptual models are more useful.


2009 ◽  
Vol 60 (5) ◽  
pp. 1233-1240 ◽  
Author(s):  
C. Jefferies ◽  
A. Duffy ◽  
N. Berwick ◽  
N. McLean ◽  
A. Hemingway

This paper outlines a rationale and scoring system for the stormwater treatment train assessment tool (STTAT) which is a proposed regulatory tool for Sustainable Urban Drainage Systems (SUDS). STTAT provides guidance and regulatory consistency for developers about the requirements of planners and the Scottish Environment Protection Agency (SEPA). The tool balances the risks of pollution to the receiving water body with the treatment provided in a treatment train. It encourages developers to take SUDS into account early, avoiding any misunderstanding of SUDS requirements at the planning stage of a development. A pessimistic view on pollution risks has been adopted since there may be a change of land use on the development in the future. A realistic view has also been taken of maintenance issues and the ‘survivability’ of a SUDS component. The development of STTAT as a response to the requirements of the Water Framework Directive is explored, the individual scores being given in tabular format for receiving water and catchment risks. Treatment scores are proposed for single SUDS components as well as multiple components within treatment trains. STTAT has been tested on a range of sites, predominantly in Scotland where both development and receiving water information was known. The operational tool in use by SEPA is presented.


2018 ◽  
Vol 20 (4) ◽  
pp. 829-845 ◽  
Author(s):  
Damian Murla Tuyls ◽  
Søren Thorndahl ◽  
Michael R. Rasmussen

Abstract Intense rainfall in urban areas can often generate severe flood impacts. Consequently, it is crucial to design systems to minimize potential flood damages. Traditional, simple design of urban drainage systems assumes agreement between rainfall return period and its consequent flood return period; however, this does not always apply. Hydraulic infrastructures found in urban drainage systems can increase system heterogeneity and perturb the impact of severe rainfall response. In this study, a surface flood return period assessment was carried out at Lystrup (Denmark), which has received the impact of flooding in recent years. A 35 years' rainfall dataset together with a coupled 1D/2D surface and network model was used to analyse and assess flood return period response. Results show an ambiguous relation between rainfall and flood return periods indicating that linear rainfall–runoff relationships will, for the analysed case study, be insufficient for flood estimation. Simulation-based mapping of return periods for flood area and volume has been suggested, and moreover, a novel approach has been developed to map local flood response time and relate this to rainfall characteristics. This approach allows to carefully analyse rainfall impacts and flooding response for a correct flood return period assessment in urban areas.


Sci ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 21 ◽  
Author(s):  
Guri Venvik ◽  
Floris C. Boogaard

Sustainable urban drainage systems (SuDS) such as swales are designed to collect, store and infiltrate a large amount of surface runoff water during heavy rainfall. Stormwater is known to transport pollutants, such as particle-bound Potential Toxic Elements (PTE), which are known to often accumulate in the topsoil. A portable XRF instrument (pXRF) is used to provide in situ spatial characterization of soil pollutants, specifically lead (Pb), zink (Zn) and copper (Cu). The method uses pXRF measurements of PTE along profiles with set intervals (1 m) to cover the swale with cross-sections, across the inlet, the deepest point and the outlet. Soil samples are collected, and the In-Situ measurements are verified by the results from laboratory analyses. Stormwater is here shown to be the transporting media for the pollutants, so it is of importance to investigate areas most prone to flooding and infiltration. This quick scan method is time and cost-efficient, easy to execute and the results are comparable to any known (inter)national threshold criteria for polluted soils. The results are of great importance for all stakeholders in cities that are involved in climate adaptation and implementing green infrastructure in urban areas. However, too little is still known about the long-term functioning of the soil-based SuDS facilities.


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