Water - Urban Water Management

Title

Reference

Author(s)

J.B. Ellis

Study type

Peer Review Journal    

Abstract

Based on the analysis of impervious surface cover and water balance studies, it is argued that conventional, separately-sewered first-generation and alternative second-generation sustainable drainage systems (SUDS) cannot provide a fully sustainable surface water management approach for urban catchment planning. An extended approach based on the introduction of micro-and meso-vegetative SUDS systems into a wider green infrastructure (GI) framework is advocated to effectively address on-site and catchment urban surface water issues. The approach is based on the integrated planning implementation of street ‘greening’, with optimisation of existing biofiltration SUDS solutions, together with green roofs, downspout disconnection and sub-catchment riparian corridors to achieve a minimum 25–30% canopy cover level. A ‘leaf-out’ inventory procedure using GIS and satellite imagery can be employed to assess potential vegetative SUDS locations and types, and their likely impact upon the urban water cycle and receiving water health. However, there is a need to ensure that GI elements are incorporated into planning approaches and protocols for urban drainage infrastructure provision.

Policy theme(s)

Urban environment >> Urban planning >> Sustainable cities
Water >> Flooding
Water >> Urban water management

Keywords

urban surface water, impermeable surface cover, biofiltration sustainable drainage systems, green infrastructure, leaf-out inventory, development planning

Entry Source:

Shortlisted for Science for Environment Policy News Alert 

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http://www.tandfonline.com/doi/abs/10.1080/09640568.2011.648752
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B.Ellis@mdx.ac.uk

Title

Modeling the impact of land use and climate change on neighborhood-scale evaporation and nighttime cooling: A surface energy balance approach

Reference

Landscape and Urban Planning
Volume 103, Issue 2, 30 November 2011, Pages 139-155

Author(s)

Lily A. House-Peters, Heejun Chang 

Study type

Peer Review Journal

Abstract

We investigated the impacts of temperature changes derived from climate change scenarios and land cover change on patterns of external residential water consumption and nighttime cooling in suburban Hillsboro, Oregon. Three downscaled climate warming scenarios and two land cover change scenarios (sprawl and dense) for the 2040s were used as inputs for an urban energy balance model, the Local-Scale Urban Meteorological Parameterization Scheme (LUMPS). Based on the surface energy fluxes simulated by the LUMPS model, we calculate that the combination of the sprawl scenario with the 3 °C temperature rise increases external water consumption by 4061 L per household for August. Alternately, dense development concomitant with temperature increase constrains increases in water consumption, but reduces nighttime cooling rates by more than 0.3 °C. Increasing the fraction of trees would increase efficiency in promoting urban cooling while reducing external water consumption. This study demonstrates that urban land cover and water use are naturally intertwined at the neighborhood scale, suggesting that urban land-use planning and water management should be fully integrated to design cities that can accommodate future population growth and development while minimizing negative impacts of potential climate change.

Policy theme(s)

Climate change and energy >> Climate change adaptation >> Social and health impacts
Land use >> Planning     
Urban environment >> Urban planning >> Healthy cities
Water >> Water consumption >> Water scarcity
Water >> Urban water management

Keywords

Urban energy balance; Water consumption; Climate change; Land cover; Temperature; LUMPS

Entry Source:

Selected for Science for Environment Policy News Alert

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http://www.sciencedirect.com/science/article/pii/S0169204611002362
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lilyhp@email.arizona.edu

Title

Benchmarking energy consumption and CO₂ emissions from rainwater-harvesting systems: an improved method by proxy

Reference

Water and Environment Journal
DOI: 10.1111/j.1747-6593.2011.00279.x

Author(s)

Sarah Ward, David Butler, Fayyaz Ali Memon

Study type

Peer Review Journal

Abstract

Life cycle analyses (LCAs) show the main operational energy contribution for rainwater-harvesting (RWH) systems come from ultraviolet (UV) disinfection and pumping rainwater from tank to building. Simple methods of estimating pump energy consumption do not differentiate between pump start-up and pump-operating energy or include pump efficiency parameters. This paper outlines an improved method incorporating these parameters that indirectly estimates pump energy consumption and carbon dioxide (CO₂) emissions using system performance data. The improved method is applied to data from an office-based RWH system. Comparison of the simple and improved methods identified the former underestimates pump energy consumption and carbon emissions by 60%. Results of the improved method corresponded well to directly measured energy consumption and energy consumption represented 0.07% of an office building's total energy consumption. Consequently, the overall energy consumption associated with RWH systems is a very minor fraction of total building energy consumption.

Policy theme(s)

Resource efficiency >> Energy efficiency
Water >> Urban water management

Keywords

carbon; cost; energy; method; proxy; rainwater harvesting

Entry Source:

Selected for Science for Environment Policy News Alert

Referred to in EC doc:

N/A

View this study at:

http://onlinelibrary.wiley.com/doi/10.1111/j.1747-6593.2011.00279.x/full
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Sw278@exeter.ac.uk

Title

Increasing urban water self-sufficiency: New era, new challenges

Reference

Journal of Environmental Management
Volume 92, Issue 1, January 2011, Pages 185-194

Author(s)

Martin Rygaard, Philip J. Binning and Hans-Jørgen Albrechtsen

Study type

Peer Review Journal 

Abstract

Urban water supplies are traditionally based on limited freshwater resources located outside the cities. However, a range of concepts and techniques to exploit alternative water resources has gained ground as water demands begin to exceed the freshwater available to cities. Based on 113 cases and 15 in-depth case studies, solutions used to increase water self-sufficiency in urban areas are analyzed. The main drivers for increased self-sufficiency were identified to be direct and indirect lack of water, constrained infrastructure, high quality water demands and commercial and institutional pressures. Case studies demonstrate increases in self-sufficiency ratios to as much as 80% with contributions from recycled water, seawater desalination and rainwater collection. The introduction of alternative water resources raises several challenges: energy requirements vary by more than a factor of ten amongst the alternative techniques, wastewater reclamation can lead to the appearance of trace contaminants in drinking water, and changes to the drinking water system can meet tough resistance from the public. Public watersupply managers aim to achieve a high level of reliability and stability. We conclude that despite the challenges, self-sufficiency concepts in combination with conventional water resources are already helping to reach this goal.

Policy theme(s)

Resource efficiency >> Water efficiency
Water >> Urban water management

Keywords

Cost; Desalination; Drivers; Energy; Rainwater collection; Wastewater reclamation

Entry Source:

Selected for Science for Environment Policy News Alert

Referred to in EC doc:

N/A

View this study at:

http://www.sciencedirect.com/science/article/pii/S030147971000294X There is a fee to view this study in full

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mar@env.dtu.dk

Title

Roof selection for rainwater harvesting: Quantity and quality assessments in Spain

Reference

Water Research
Volume 45, Issue 10, May 2011, Pages 3245-3254

Author(s)

Ramon Farreny, Tito Morales-Pinzón, Albert Guisasola, Carlota Tayà, Joan Rieradevall and Xavier Gabarrell

Study type

Peer Review Journal

Abstract

Roofs are the first candidates for rainwater harvesting in urban areas. This research integrates quantitative and qualitative data of rooftop stormwater runoff in an urban Mediterranean-weather environment. The objective of this paper is to provide criteria for the roof selection in order to maximise the availability and quality of rainwater. Four roofs have been selected and monitored over a period of 2 years (2008-2010): three sloping roofs - clay tiles, metal sheet and polycarbonate plastic - and one flat gravel roof. The authors offer a model for the estimation of the runoff volume and the initial abstraction of each roof, and assess the physicochemical contamination of roof runoff. Great differences in the runoff coefficient (RC) are observed, depending mostly on the slope and the roughness of the roof. Thus, sloping smooth roofs (RC > 0.90) may harvest up to about 50% more rainwater than flat rough roofs (RC = 0.62). Physicochemical runoff quality appears to be generally better than the average quality found in the literature review (conductivity: 85.0 ± 10.0 µS/cm, total suspended solids: 5.98 ± 0.95 mg/L, total organic carbon: 11.6 ± 1.7 mg/L, pH: 7.59 ± 0.07 upH). However, statistically significant differences are found between sloping and flat rough roofs for some parameters (conductivity, total organic carbon, total carbonates system and ammonium), with the former presenting better quality in all parameters (except for ammonium). The results have an important significance for local governments and urban planners in the (re)design of buildings and cities from the perspective of sustainable rainwater management. The inclusion of criteria related to the roof's slope and roughness in city planning may be useful to promote rainwater as an alternative water supply while preventing flooding and water scarcity.

Policy theme(s)

Urban environment >> Urban planning >> Construction
Water >> Urban water management

Keywords

City ecodesign, Runoff coefficient, Sustainable urbanism, Stormwater runoff, Urban environment, Water management

Entry Source:

Selected for Science for Environment Policy News Alert

Referred to in EC doc:

N/A

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http://www.sciencedirect.com/science/article/pii/S0043135411001540
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ramon@ineditinnova.com

Title

Urban groundwater baseflow influence upon inorganic river-water quality: The River Tame headwaters catchment in the City of Birmingham, UK

Reference

Journal of Hydrology
Volume 400, Issues 1-2, 30 March 2011, Pages 206-222

Author(s)

Michael O. Rivett, Paul A. Ellis and Rae Mackay

Study type

Peer Review Journal

Abstract

Understanding the linkage between urban land, groundwater, baseflow and river contamination at the city scale is lacking. This study evaluates the influence of inorganic (major/minor ions and metals) groundwater contamination in the Triassic sandstone-Quaternary deposits aquifer system underlying the City of Birmingham, UK upon the baseflow and water quality of the river Tame. Baseflow water-quality data have been collected from a riverbed piezometer network installed in the 7.4 km reach crossing the effluent unconfined sandstone aquifer and compared to river and aquifer water-quality data. Overall, the inorganic chemical quality of the baseflow was not as poor as potentially surmised from the urbanisation present. Baseflow impact upon river-water quality was also low. These conclusions were underpinned by evidences of: limited river-water quality changes along the reach; some river concentrations being diluted by better quality baseflow; only occasional breaching of water-quality criteria; limited impact upon river-reach quality local to elevated baseflow dicharges; natural attenuation occurrence within the riverbed; and, modest, albeit somewhat uncertain, baseflow mass fluxes. Baseflow fluxes to the reach were in the ranges 100-3500 t/yr for major ions, 1-50 t/yr for minor ions and 1-500 kg/yr for toxic metals with zinc and nickel most prominent. The sporadic occurrence of elevated baseflow concentrations was ascribed to discrete groundwater plume discharges. More detailed sub-reach studies would be required to fully resolve discrete plume baseflow contributions and improve mass flux estimates. Not uncommonly, the urban river studied was already contaminated and hence persistent baseflow fluxes may assume more importance if the river became cleaner through other control measures. Future research should hence consider the emergent significance of urban baseflows. There are needs to: conduct similar studies to investigate if city-scale baseflow impacts are comparable elsewhere; research the importance of spatially and temporally dynamic attenuation in the riverbed; and, develop improved baseflow mass flux estimation methods.

Policy theme(s)

Water>>Urban water management
Water >> Water quality >>Water pollution and safety

Keywords

Groundwater-surface-water interactions; Urban; Baseflow; Metals; Inorganic hydrochemistry

Entry Source:

N/A

Referred to in EC doc:

Shortlisted for Science for Environment Policy News Alert

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http://www.sciencedirect.com/science/article/pii/S0022169411000618 
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M.O.Rivett@bham.ac.uk

Title

Urban stormwater treatment using bioretention

Reference

Journal of Hydrology
Volume 397, Issues 3-4, 3 February 2011, Pages 167-174

Author(s)

Sam A. Trowsdale and Robyn Simcock

Study type

Peer Review

Abstract

Urban stormwater has negative environmental and ecological effects.Bioretention systems are starting to be used in efforts to mitigate these effects. A bioretention system receiving water from a light industrial catchment and a busy road was designed, built and monitored for changes in soil physics as well as hydrological and hydrochemical efficiency. The soils in the bioretention system were designed to have high metal removal potential and high permeability to compensate for undersized bioretention volume.The inflow hydrograph was a series of sharp peaks with little baseflow, typical of runoff from impervious surfaces. The bioretention system smoothed the hydrograph by reducing peak flow and volume for all 12 events monitored in detail. Overflow occurred in 10 events indicating the increased permeability did not fully compensate for the undersized volume. Runoff was heavily polluted with sediment and heavy metals, in particular zinc. The majority of the zinc, lead and Total Suspended Sediments were removed from the stormwater that flowed through the bioretention system, with TSS and total zinc concentrations reducing by orders of magnitude. Despite high removal efficiency, median concentrations of zinc exiting the bioretention system still exceeded ecosystem health guidelines and the bioretention system was both a source and sink of copper.

Policy theme(s)

Water >> Urban water management
Water >> Water quality >> Water pollution and safety

Keywords

Bioretention, Raingarden, Biofilter, Urban stormwater, Runoff, Stormwater BMP

Entry Source:

Shortlisted for Science for Environment Policy News Alert

Referred to in EC doc:

N/A

View this study at:

http://www.sciencedirect.com/science/article/pii/S0022169410007195
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S.Trowsdale@auckland.ac.nz

Title

Reference

Reviews in Environmental Science and Biotechnology
Volume 9, Number 4, 291-296
DOI: 10.1007/s11157-010-9225-4

Author(s)

Rae Mackay and Ewan Last

Study type

Peer Review Journal

Abstract

Climate shifts, environmental degradation, aging infrastructure, energy adaptation and population growth are impacting many cities worldwide and will force changes to the way water is managed in the future for most cities around the world. To help meet these challenges, the SWITCH European Framework VI project is developing decision support tools to assist city stakeholder communities to scope future options for integrated urban water management (IUWM). City Water Balance (CWB) is one of several simulation tools being developed within SWITCH as part of the City Water integrated knowledge base system/decision support system. CWB is a scoping tool developed to allow the rapid assessment of alternative water management strategies for a city. The tool outputs indicator data on water demand, quality, energy consumption, and simplified life-cycle cost. The data requirements of City Water Balance allow a model to be established quickly from extant spatial mapping. It advances previous work of Integrated Urban Water Management (IUWM) scoping models in two ways. The first is the integration of natural systems more fully into the urban water cycle description. The second is the extension to address energy consumption as well as life cycle costs. The initial application of the model to Birmingham (UK) using historical data for verification and validation has provided a valuable illustration of the effectiveness of the model.

Policy theme(s)

Water >> Urban water management

Keywords

Decision support, Scoping model, Urban water management, Life cycle cost,

Entry Source:

Selected for Science for Environment Policy News Alert

Referred to in EC doc:

N/A

View this study at:

http://www.springerlink.com/content/b011v68h126lh478/fulltext.pdf
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Contact the study author at:

r.mackay@bham.ac.uk