In order to improve the stormwater regulation functions of urban greenways on the basis of literature research and case study the relationships between urban greenway and low impact development LID and green stormwate...In order to improve the stormwater regulation functions of urban greenways on the basis of literature research and case study the relationships between urban greenway and low impact development LID and green stormwater infrastructure GSI are analyzed. Then the classification system of urban greenways is proposed based on their stormwater regulation function and the suitable technical measures for stormwater management which can be used in different kinds of greenways are selected. According to China’s urban planning system the greenway planning method combined with the urban drainage system is developed and the design methods of the greenway stormwater system and individual stormwater facilities are put forward. The relationships between the greenway stormwater system and other systems are also analyzed in terms of stormwater inlet vertical design and overflow.Finally the waterfront greenway and street greenway demonstration projects in Jiaxing City which adopts the above concept and method are introduced. The results show that the reduction rates of annual total stormwater runoff and average total runoff contaminants TSS of the stormwater system are not less than 30% and 40% respectively.展开更多
The strengths weaknesses opportunities and threats SWOT analysis method is applied to assess the feasibility of traditional stormwater management and low impact development LID in China.The results show that tradition...The strengths weaknesses opportunities and threats SWOT analysis method is applied to assess the feasibility of traditional stormwater management and low impact development LID in China.The results show that traditional stormwater management has many disadvantages e.g.only stormwater collection and discharge or flooding peak-flow regulation is taken into consideration but lack of many important functions such as on-site infiltration non-point pollution control ecological treatment etc.Meanwhile as a new stormwater management concept the LID system has many advantages e.g.LID can not only control rainwater quantity but also effectively prevent non-point pollution. Moreover LID is easy for implementation and cost effective and operation and management can also be done easily.LID has attracted more and more attention from governmental authorities at different levels and the majority of practitioners. Therefore LID has bright prospects for wide applications in China.展开更多
Among various schemes to reuse and recycle the limited urban fresh water resources, sustainable urban stormwater management, such as water sensitive urban design and rainwater harvesting, has been recognized as one of...Among various schemes to reuse and recycle the limited urban fresh water resources, sustainable urban stormwater management, such as water sensitive urban design and rainwater harvesting, has been recognized as one of the most efficient and economically viable approaches. Storm runoff shall be treated as close as possible to its source before it is reused or discharged into public drainage network or receiving waters to enhance the water environment quality. Bioretention swale/basin, which has been commonly applied to treat runoff from roads, car parks, cyclist and pedestrian paths, rooftops, etc., is recognized to be the most efficient and aesthetic pleasing way to harvest rainwater in urban settings, and other longish shape runoff catchment area. This paper studied over 10 bioretention swales/basins applications in temperate region worldwide covering China, Germany, Norway, Austria, USA, and Australia. Key steps in bioretention swale/basin design and implementation in temperate region were investigated, such as strategic bioretention scheme selection, flow conveyance and hydraulic capacity design, filtering media profile, vegetation scheme selection and maintenance scheme, and suggestion and key design parameters. The critical path and parameters of bioretention swale/basin design which enhanced the effectiveness and efficiency of its application for rainwater harvesting in temperate regions were derived.展开更多
In order to relieve urban environmental problems due to stormwater runoff,approaches involving the planning of green space for sponge city construction were previously proposed.In this study,water retention characteri...In order to relieve urban environmental problems due to stormwater runoff,approaches involving the planning of green space for sponge city construction were previously proposed.In this study,water retention characteristics of 168 green spaces are surveyed to develop estimates of stormwater retention in Shanghai City’s center,suburbs and outskirts.Multidisciplinary methods of community investigation,soil tests,artificial rainfall simulation experiments,and simulations in Autodesk storm and sanitary analysis(SSA)and storm water management model(SWMM)are used.The factors affecting the capacity of stormwater management are identified and used to calculate storage estimates.The relationships among rainfall interception capacity(RIC),runoff,soil water storage properties,and vegetative cover are analyzed,which can provide the theoretical foundation for the assessment of the water-holding capacity in urban green spaces.A criterion for the selection of low impact development(LID)techniques for the Shanghai area is developed on the basis of the data from this study.展开更多
This paper presents the practice of stormwater management in Hong Kong. It gives an overview of the current situation as regards to the organization, policies and strategies, the technologies adopted, and the economi...This paper presents the practice of stormwater management in Hong Kong. It gives an overview of the current situation as regards to the organization, policies and strategies, the technologies adopted, and the economics and financing aspects relevant to implementation of the management practices. The influencing factors and trends in future development of stormwater management are also discussed.展开更多
In the context of disaster normalization,the concept of“resilience”has been gradually introduced into the field of disaster prevention and mitigation in urban communities.In order to resist the increasingly frequent...In the context of disaster normalization,the concept of“resilience”has been gradually introduced into the field of disaster prevention and mitigation in urban communities.In order to resist the increasingly frequent disasters caused by extreme weather,it is necessary to shift the focus of building resilient urban communities to the level of stormwater management.Community resilience is a disaster prevention and mitigation capability based on community resources.In order to solve the deficiency of storm and flood management in the current construction of resilient communities in China,it is necessary to establish a quantitative evaluation system to evaluate it.This paper uses the analytic hierarchy process and Delphi method to establish a community resilience evaluation system from the perspectives of community material space level,community management level and individual level.Then three communities in Hefei City,Anhui Province are selected for practical application of the system,and corresponding optimization and transformation strategies are proposed.The results show that:(1)The resilience of community stormwater management is closely related to the integrated environment of the community,the allocation of flood control facilities and the daily disaster prevention and mitigation management;(2)The ability of disaster prevention and mitigation and the awareness of public participation of the residents in all communities are relatively weak,and the communities invest less in the popularization of stormwater management wisdom;and(3)Resilient communities should not only pay attention to the construction of non-engineering disaster prevention measures,but also to the application of small-scale green infrastructure oriented toward stormwater management.展开更多
The positive role of urban green stormwater infrastructure(GIS)and wetland park construction in the process of“sponge city”construction is analyzed by expounding the connotation and problems of“sponge city”constru...The positive role of urban green stormwater infrastructure(GIS)and wetland park construction in the process of“sponge city”construction is analyzed by expounding the connotation and problems of“sponge city”construction.Through the analysis of relevant cases,the realization approaches of combing different types of GIS with wetland park landscape design are interpreted,and it is pointed out that different types of GIS can guide the further practice of“sponge city”construction.展开更多
INTRODUCTION Humans and plants depend on an adequate supply of clean water for numerous reasons,from food production to sustaining terrestrial and aquatic life.The average Virginia resident uses about 47 gallons(178 L...INTRODUCTION Humans and plants depend on an adequate supply of clean water for numerous reasons,from food production to sustaining terrestrial and aquatic life.The average Virginia resident uses about 47 gallons(178 L)of fresh water daily(VDEQ 2008).While a majority of Virginians are provided water from a centralized,public utility,there are nearly two million Virginia residents who depend on well water as their main source(VDH 2008).Replenishing groundwater withdrawals depends on recharge(water moving from the surface to groundwater)from infiltration of precipitation through permeable surfaces in the environment;an important part of the hydrologic,or water,cycle(VDEQ 2010).Forests and grasslands provide much of the available recharge area due to their high capacities to infiltrate precipitation.However,the urbanization process is rapidly converting forested areas and grasslands to commercial,residential,or industrial developments.This conversion creates a significant increase in impervious surfaces such as concrete,asphalt,building roofs,and even compacted vegetated sites(U.S.EPA 2003).Impervious surfaces decrease infiltration and groundwater recharge.They also generate increases in stormwater runoff;defined as any precipitation from a rain or snow event that flows off of an impervious surface.As water runs off urban impervious surfaces,it picks up sediment,oils,debris,nutrients,chemicals,and bacteria.The runoff is then collected in a conveyance system,transported,and discharged to surface waters such as creeks and rivers;most of the time without any type of water quality treatment(U.S.EPA 2003;Paul and Meyer 2001).In addition to carrying pollutants,the runoff is also typically warmer than the receiving surface waters.The increased volume and velocity of the stormwater runoff erodes soil and stream channels and can lead to stream“blow out.”Water quality is degraded and aquatic habitats are adversely altered(Meyer,et al.2005,Booth and Jackson 1997).Due to the interconnected nature of watersheds,the degraded water travels downstream causing subsequent problems.The effect of increased development is an increase in stormwater runoff and associated pollutants into surface waters and a decrease in infiltration for groundwater recharge and stream base flows.Traditional practices for mitigating stormwater runoff impacts have targeted the management of peak runoff by using storage facilities such as detention and retention ponds.Mounting evidence that these methods are inadequate prompted the National Research Council in 2008 to advocate a shift to Low Impact Development(LID)practices to better meet stormwater quality and quantity management goals.LID is based on a set of techniques used in Prince Georges County,Maryland(Prince Georges County 1999).LID seeks to restore the natural hydrology of a site by minimizing the creation of impervious surfaces and increasing infiltration of runoff volume.The ineffectiveness of conventional management approaches and the implementation of the Chesapeake Bay and other critical watershed Total Maximum Daily Loads(TMDLs)caused Virginia to revise its entire process for regulating stormwater.LID and Environmental Site Design(ESD)practices are now used to design sites to meet hydrologic goals and to treat runoff to meet a net site nutrient export standard(Battiata et al.2010).As of the date of this paper,15 of these best management practices,or BMPs,have been approved for use by Virginia(Virginia Stormwater BMP Clearinghouse 2011).Similar approaches are being considered and adopted in other Chesapeake Bay jurisdictions,as well as nationally.The responsibility of stormwater management can be fragmented between state,local,and municipal government(Roy,et al.2008),often differing from watershed to watershed.Because LID is decentralized,it changes the management focus from a large,regional scale to a site scale.Changes at the residential lot level can generate much greater infiltration over the watershed.Each homeowner can significantly reduce the stormwater load leaving their property,thereby improving surface water quality and helping to recharge groundwater reserves.From a green building perspective,LID techniques can provide a substantial credit under the LEEDS-ND(Leadership in Energy and Environmental Design-Neighborhood Development)program.The objective of this paper is to provide a relative context for runoff at the site scale,and an overview of the available BMPs that may be applicable.展开更多
China started a Sponge City program to offset the adverse impacts of urban developments and to tackle many water-related problems.By emphasizing stormwater management practices with“natural solutions”,many positive ...China started a Sponge City program to offset the adverse impacts of urban developments and to tackle many water-related problems.By emphasizing stormwater management practices with“natural solutions”,many positive results have been achieved.The operation and maintenance(O&M)of Sponge City to support long-term success gained considerable focus.China is facing challenges many developed countries have encountered,as well as unique ones due to specific social,economic,and environmental conditions.This study identified and discussed Sponge City O&M challenges:(1)scheduling challenges,(2)technical challenges,(3)in short of local regulation/ordnance,(4)inadequate O&M assessment standard,(5)underprovided training,(6)PPP related concerns,(7)inter-agency coordination needs,(8)ownership and responsible party issues,(9)substandard documentation,and(10)funding and financial concerns.Selected cases and progress in pilot cities are introduced in the discussions.展开更多
Gross pollutants are the primary targeted pollutants in urban catchment management for urban water quality improvement as well as mitigation of flood. Apart from aesthetically unattractive because of its visibility, g...Gross pollutants are the primary targeted pollutants in urban catchment management for urban water quality improvement as well as mitigation of flood. Apart from aesthetically unattractive because of its visibility, gross pollutants also contributes to degradation of river water quality and loss of aquatic habitat as it carries harmful pollutants such as oxygen demanding material, hydrocarbons and heavy metals. This study analyzed trend of gross pollutant generated from two urban residential areas located in Selangor, Malaysia. The median value of gross pollutant load obtained fi'om the Amanah Apartment and Bandar Botanic are 347.41 kg/ha/year and 32.46 kg/ha/year, respectively. Relationship between gross pollutant wet load with rainfall depths was derived using regression equation. A significant trend of increasing gross pollutant wet load into drainage system with increasing rainfall depth was observed. The behavior of pollutant load is related to the one observed in Australia.展开更多
Many cities are adopting low impact development(LID)technologies(a type of nature-based solution)to sustainably manage urban stormwater in future climates.LIDs,such as bioretention cells,green roofs,and permeable pave...Many cities are adopting low impact development(LID)technologies(a type of nature-based solution)to sustainably manage urban stormwater in future climates.LIDs,such as bioretention cells,green roofs,and permeable pavements,are developed and applied at small-scales in urban and peri-urban settings.There is an interest in the large-scale implementation of these technologies,and therefore assessing their performance in future climates,or conversely,their potential for mitigating the impacts of climate change,can be valuable evidence in support of stormwater management planning.This paper provides a literature review of the studies conducted that examine LID function in future climates.The review found that most studies focus on LID performance at over 5 km2scales,which is quite a bit larger than traditional LID sizes.Most paper used statistical downscaling methods to simulate precipitation at the scale of the modelled LID.The computer model used to model LIDs was predominantly SWMM or some hybrid version of SWMM.The literature contains examples of both vegetated and unvegetated LIDs being assessed and numerous studies show mitigation of peak flows and total volumes to high levels in even the most extreme climates(characterized by increasing rainfall intensity,higher temperatures,and greater number of dry days in the inter-event period).However,all the studies recognized the uncertainty in the projections with greatest uncertainty in the LID’s ability to mitigate storm water quality.Interestingly,many of the studies did not recognize the impact of applying a model intended for small-scale processes at a much larger scale for which it is not intended.To explore the ramifications of scale when modelling LIDs in future climates,this paper provides a simple case study of a large catchment on Vancouver Island in British Columbia,Canada,using the Shannon Diversity Index.PCSWMM is used in conjunction with providing regional climates for impacts studies(PRECIS)regional climate model data to determine the relationship between catchment hydrology(with and without LIDs)and the information loss due to PCSWMM’s representation of spatial heterogeneity.The model is applied to five nested catchments ranging from 3 to 51 km2and with an RCP4.5 future climate to generate peak flows and total volumes in 2022,and for the period of 2020–2029.The case study demonstrates that the science behind the LID model within PC stormwater management model(PCSWMM)is too simple to capture appropriate levels of heterogeneity needed at larger-scale implementations.The model actually manufactures artificial levels of diversity due to its landuse representation,which is constant for every scale.The modelling exercise demonstrated that a simple linear expression for projected precipitation vs.catchment area would provide comparable estimates to PCSWMM.The study found that due to the spatial representation in PCSWMM for landuse,soil data and slope,slope(an important factor in determining peak flowrates)had the highest level of information loss followed by soil type and then landuse.As the research scale increased,the normalized information loss index(NILI)value for landuse exhibited the greatest information loss as the catchments scaled up.The NILI values before and after LID implementation in the model showed an inverse trend with the predicted LID mitigating performance.展开更多
Continuous urbanization over the last few years has led to the increase in impervious surfaces and stormwater runoff.Low Impact Development(LID)is currently receiving increased attention as a promising strategy for su...Continuous urbanization over the last few years has led to the increase in impervious surfaces and stormwater runoff.Low Impact Development(LID)is currently receiving increased attention as a promising strategy for surface runoff management.To analyze the performance of LID practices for surface runoff management,a longterm hydrological modeling from 2001 to 2015 along with a cost-effectiveness analysis were carried out on a campus in Dresden,Germany.Seven LID practices and six precipitation scenarios were designed and simulated in a Storm Water Management Model(SWMM).A cost-effectiveness analysis was conducted by calculating the lifecycle costs and runoff removal rate of LID practices.Results demonstrated that the LID practices significantly contributed to surface runoff mitigation in the study area.The LID performance was primarily affected by the length of the precipitation scenarios and LID implementing schemes.The runoff removal rate of the LID practices fluctuated significantly when the rainfall scenario was shorter than 12 months.When the rainfall scenario exceeded 1 year the effects on the runoff removal rate was constant.The combination of an infiltration trench,permeable pavement,and rain barrel(IT+PP+RB),was the best runoff control capacity with a removal rate ranging from 23.2% to 27.4%.Whereas,the rain barrel was the most cost-effective LID option with a costeffectiveness(C/E)ratio ranged from 0.34 to 0.41.The modeling method was improved in this study by conducting long-term hydrological simulations with different durations rather than short-term simulations with single storms.In general,the methods and results of this study provided additional improvements and guidance for decision-making process regarding the implementation of appropriate LID practices.展开更多
Stimulated by the recent USEPA's green stormwater infrastructure (GSI) guidance and policies, GS1 systems have been widely implemented in the municipal area to control the combined sewer overflows (CSOs), also kn...Stimulated by the recent USEPA's green stormwater infrastructure (GSI) guidance and policies, GS1 systems have been widely implemented in the municipal area to control the combined sewer overflows (CSOs), also known as low impact development (LID) approaches. To quantitatively evaluate the performance of GSI systems on CSO and urban flooding control, USEPA-Stormwater Management Model (SWMM) model was adopted in this study to simulate the behaviors of GSI systems in a well- developed urban drainage area, PSW45, under different circumstances. The impact of different percentages of stormwater runoff transported from impervious surfaces to the GSI systems on CSO and urban flooding control has also been investigated. Results show that with current buildup, GSI systems in PSW45 have the best performance for low intensity and short duration events on both volume and peak flow reductions, and have the worst pertbrmance tor high intensity and long durataon events. Since the low intensity and short duration events are dominant from a long-term perspective, utilizing GSI systems is considered as an effective measure of CSO control to meet the long-term controlstrategy for PSW45 watershed. However, GSI systems are not suitable for the flooding control purpose in PSW45 due to the high occurrence possibility of urban flooding during or after high intensity events where GSI systems have relatively poor performance no matter for a short or long duration event,展开更多
Urban underlying surface has been greatly changed with rapid urbanization, considered to be one of the major causes for the destruction of urban natural hydrological processes. This has imposed a huge challenge for st...Urban underlying surface has been greatly changed with rapid urbanization, considered to be one of the major causes for the destruction of urban natural hydrological processes. This has imposed a huge challenge for stormwater management in cities. There has been a shift from gray water management to green stormwater management thinking. The green stormwater infrastructure (GSI) is regarded as an effective and cost-efficient stormwater management eco-landscape approach. China's GSI practice and the development of its theoretical framework are still in the initial stage. This paper presents an innovative framework for stormwater management, integrating green stormwater infrastructure and landscape security patterns on a regional scale based on an urban master plan. The core concept of green stormwater infrastructure eco-planning is to form an interconnected GSI network (i.e., stormwater management landscape security pattern) which consists of the location, portion, size, layout, and structure of GSI so as to efficiently safeguard natural hydrological processes. Shanghai Lin- gang New City, a satellite new town of Shanghai, China was selected as a case study for GSI studies. Simulation analyses of hydrological processes were carried out to identify the critical significant landscape nodes in the high- priority watersheds for stormwater management. GSI should be planned and implemented in these identified landscape nodes. The comprehensive stormwater manage- ment landscape security pattern of Shanghai Lingang New City is designed with consideration of flood control, stormwater control, runoff reduction, water quality protec- tion, and rainwater utilization objectives which couldprovide guidelines for smart growth and sustainable development of this city.展开更多
In planning the George W.Bush Presidential Center in Dallas,Texas,former First Lady Laura Bush presented a very clear vision of what the Center should epitomize:“Because George was the first president of the new mill...In planning the George W.Bush Presidential Center in Dallas,Texas,former First Lady Laura Bush presented a very clear vision of what the Center should epitomize:“Because George was the first president of the new millennium,I wanted it to be forward and modern.”1 For the president and Mrs.Bush this meant making the building and landscape environmentally responsible,beautiful,and welcoming.In particular,their love of native Texas landscapes was an important framework for transforming the project’s urban site into a park that was sustainable and experientially rich for visitors.Sustainability was addressed from the start with smart planning that privileged contiguous parkland over impermeable surfaces and structures.Simultaneous consideration of every landscape component—-stormwater,plants,soil,topography,and more—netted cohesive natural systems that are better able to succeed with short-term establishment and provide enduring long-term health,the ultimate goals for a sustainable landscape.展开更多
Kansas State University(KSU)is a land-grant institution,with nine colleges and 23,000 students.The 668-acre main campus is located within the City of Manhattan,Kansas,which has a population of approximately 45,000.Thr...Kansas State University(KSU)is a land-grant institution,with nine colleges and 23,000 students.The 668-acre main campus is located within the City of Manhattan,Kansas,which has a population of approximately 45,000.Through a bottom-up process the university has been seeking to integrate sustainability in student life,curriculum,operations,research,and engagement.展开更多
This paper presents an approach described as“non-traditional”for restoring water quality and ecosystem services that have been degraded as a result of excess nitrogen.It focuses on emerging technologies often referr...This paper presents an approach described as“non-traditional”for restoring water quality and ecosystem services that have been degraded as a result of excess nitrogen.It focuses on emerging technologies often referred to as green infrastructure.These technologies may provide cost effective alternatives to traditional,gray infrastructure such as sewering and is likely to provide significant co-benefits including the creation of local jobs,the preservation of real estate values,and habitat enhancement.The paper focuses on the Three Bays estuary on Cape Cod to illustrate the benefits and potential of green infrastructure technologies.The Three Bays estuary is presented as a case study and as a representative example of implementation of the broader Cape Cod Water Quality Management Plan Update(208 Plan Update)-a nationally-recognized watershed planning project designed to provide a pathway for the fifteen towns of Cape Cod to achieve compliance with Section 208 of the Clean Water Act.The Three Bays estuary and embayment system is a scenic Cape Cod bay that hosts sailing,kayaking,swimming and shellfishing and is located in the Town of Barnstable.It is comprised of three primary segments that include West Bay,North Bay and Cotuit Bay.Sub-systems include Prince Cove that flows into North Bay,the Narrows that flows between North Bay and Cotuit Bay and Eel Pond that flows into East Bay(see Figure 1).The Massachusetts Estuaries Project(MEP)is a state-sanctioned watershedmodeling project that assesses the conditions of the state’s estuaries and required restoration goals.Its technical report(2006)indicates that the water quality of the Three Bays system has resulted in seriously degraded to moderately degraded habitat.The system is listed as an impaired water body on the US Environmental Protection Agency(EPA)303d list of impaired waters.An approved Total Maximum Daily Load(TMDL)for nitrogen has been established for the embayment.This assessment is supported by more recent empirical water quality data collected within the embayment.The more current data documents a continuing decline in water quality with more common algae blooms(see Figure 2).展开更多
The Centre of Excellence at Okanagan College in Penticton,British Columbia is being designed as one of the most innovative and sustainable post-secondary facilities in the world.On schedule for design and construction...The Centre of Excellence at Okanagan College in Penticton,British Columbia is being designed as one of the most innovative and sustainable post-secondary facilities in the world.On schedule for design and construction to be complete by April 2011,the two-storey multi-purpose facility has a mandate to provide trades and technology training and professional development to students from the province of British Columbia and beyond.It is aimed at attaining the highest standard of sustainable building design,the Living Building Challenge.The building will support a syllabus with a focus on the design,installation,and support of sustainable building technologies and processes,and the development and application of alternative and renewable energy.The building itself will become an essential element of the educational programs that will reside there,a teaching tool for education on building trades and engineering technologies.In addition,the Okanagan Research Innovation Centre will be incorporated into the building,providing opportunities for start-up companies to develop and prototype new green technologies in a supportive and synergistic environment.This article will demonstrate that a project with this level of sustainable objectives is achievable at a cost comparable to conventional building design.It will address how this can be attained through an integrated design process,along with the numerous innovative features that have been incorporated into the building design to help it function with a small environmental impact,and a large educational one.展开更多
Higher education institutions are implementing environmentally friendly practices as never before.According to a 2009 survey undertaken by the Sustainable Endowments Institute,a nonprofit organization based in Cambrid...Higher education institutions are implementing environmentally friendly practices as never before.According to a 2009 survey undertaken by the Sustainable Endowments Institute,a nonprofit organization based in Cambridge,Massachusetts,more than 300 colleges and universities have become greener over the past few years despite tighter budgets and widely fluctuating energy costs.Three-quarters of these schools have adopted green building policies and about 44 percent have at least one LEED-certified building or are in the process of constructing one.Emory University in suburban Druid Hills outside Atlanta,Georgia,is one of the more forward-looking of these institutions.In 2005,university president James Wagner began the greening of the 600-acre campus by forming a committee to develop an environmental agenda for guiding the institution’s future.The following year,Emory opened an Office of Sustainability Initiatives to implement this policy.The university’s long-term goals include reducing campus energy use by 25 percent per square foot and food,materials,and electronic wastes by 65 percent per square foot—all by 2015.Already,the installation of water-saving fixtures and irrigation in accordance with drought restrictions helped to reduce water consumption by 12 percent between 2007 and 2009.As part of its eco-friendly policy,Emory now requires all new structures on campus to earn a LEED silver rating from the U.S.Green Building Council.So far,the university has achieved LEED certification of 13 buildings on campus—5 gold,5 silver,and 3 certified,including classroom,administrative,research,and healthcare facilities.In addition,six completed or nearly completed buildings are awaiting LEED certification.Ayers Saint Gross Architects and Planners of Baltimore helped to boost the sustainability at Emory,beginning in 1998 with a master plan for the campus.The firm updated this strategy in 2005 just as the university began studying ways of becoming greener.Responding to this mandate,the plan called for native plantings and recycling receptacles on campus,and rerouting vehicular traffic away from the university core,among other environmentally sensitive measures.Ayers Saint Gross has gone on to complete four,eco-friendly buildings at Emory.Each design conveys a distinctive architectural identity through varied types of metal panels and fenestration patterns.At the same time,the buildings’red-tiled roofs and exteriors of stucco and stone harmonize with the historic architecture originally designed by Beaux-Arts architect Henry Hornbostel at the heart of the campus.These new structures include a mixed-use building housing the university’s admissions office,a bookstore,and a café.A green roof is positioned over the parking garage connected to this building.Rainwater is collected in tanks below grade for irrigating the site.More sophisticated are the rainwater harvesting and graywater recycling systems devised by Ayers Saint Gross for two of three freshman residence halls designed by the firm.These green measures are particularly well suited to residence halls as they capitalize on constant water usage in the buildings through toilets,sinks,showers,and laundry facilities.At the same time,they educate the students as to the merits of sustainable design by making visible the process of collecting and recycling water from inside and outside the residence halls.展开更多
基金The National Natural Science Foundation of China(No.51208020)
文摘In order to improve the stormwater regulation functions of urban greenways on the basis of literature research and case study the relationships between urban greenway and low impact development LID and green stormwater infrastructure GSI are analyzed. Then the classification system of urban greenways is proposed based on their stormwater regulation function and the suitable technical measures for stormwater management which can be used in different kinds of greenways are selected. According to China’s urban planning system the greenway planning method combined with the urban drainage system is developed and the design methods of the greenway stormwater system and individual stormwater facilities are put forward. The relationships between the greenway stormwater system and other systems are also analyzed in terms of stormwater inlet vertical design and overflow.Finally the waterfront greenway and street greenway demonstration projects in Jiaxing City which adopts the above concept and method are introduced. The results show that the reduction rates of annual total stormwater runoff and average total runoff contaminants TSS of the stormwater system are not less than 30% and 40% respectively.
基金The National Science and Technology Major Project of China(No.2010ZX07320-003)
文摘The strengths weaknesses opportunities and threats SWOT analysis method is applied to assess the feasibility of traditional stormwater management and low impact development LID in China.The results show that traditional stormwater management has many disadvantages e.g.only stormwater collection and discharge or flooding peak-flow regulation is taken into consideration but lack of many important functions such as on-site infiltration non-point pollution control ecological treatment etc.Meanwhile as a new stormwater management concept the LID system has many advantages e.g.LID can not only control rainwater quantity but also effectively prevent non-point pollution. Moreover LID is easy for implementation and cost effective and operation and management can also be done easily.LID has attracted more and more attention from governmental authorities at different levels and the majority of practitioners. Therefore LID has bright prospects for wide applications in China.
基金National Key Science and Technology Special Project, China(No. 2008zx07317-007-105)
文摘Among various schemes to reuse and recycle the limited urban fresh water resources, sustainable urban stormwater management, such as water sensitive urban design and rainwater harvesting, has been recognized as one of the most efficient and economically viable approaches. Storm runoff shall be treated as close as possible to its source before it is reused or discharged into public drainage network or receiving waters to enhance the water environment quality. Bioretention swale/basin, which has been commonly applied to treat runoff from roads, car parks, cyclist and pedestrian paths, rooftops, etc., is recognized to be the most efficient and aesthetic pleasing way to harvest rainwater in urban settings, and other longish shape runoff catchment area. This paper studied over 10 bioretention swales/basins applications in temperate region worldwide covering China, Germany, Norway, Austria, USA, and Australia. Key steps in bioretention swale/basin design and implementation in temperate region were investigated, such as strategic bioretention scheme selection, flow conveyance and hydraulic capacity design, filtering media profile, vegetation scheme selection and maintenance scheme, and suggestion and key design parameters. The critical path and parameters of bioretention swale/basin design which enhanced the effectiveness and efficiency of its application for rainwater harvesting in temperate regions were derived.
文摘In order to relieve urban environmental problems due to stormwater runoff,approaches involving the planning of green space for sponge city construction were previously proposed.In this study,water retention characteristics of 168 green spaces are surveyed to develop estimates of stormwater retention in Shanghai City’s center,suburbs and outskirts.Multidisciplinary methods of community investigation,soil tests,artificial rainfall simulation experiments,and simulations in Autodesk storm and sanitary analysis(SSA)and storm water management model(SWMM)are used.The factors affecting the capacity of stormwater management are identified and used to calculate storage estimates.The relationships among rainfall interception capacity(RIC),runoff,soil water storage properties,and vegetative cover are analyzed,which can provide the theoretical foundation for the assessment of the water-holding capacity in urban green spaces.A criterion for the selection of low impact development(LID)techniques for the Shanghai area is developed on the basis of the data from this study.
文摘This paper presents the practice of stormwater management in Hong Kong. It gives an overview of the current situation as regards to the organization, policies and strategies, the technologies adopted, and the economics and financing aspects relevant to implementation of the management practices. The influencing factors and trends in future development of stormwater management are also discussed.
基金The National Natural Science Foundation of China(41601581)The Science Technology Plan Project for Construction Industry of Anhui Province(2011YF-32).
文摘In the context of disaster normalization,the concept of“resilience”has been gradually introduced into the field of disaster prevention and mitigation in urban communities.In order to resist the increasingly frequent disasters caused by extreme weather,it is necessary to shift the focus of building resilient urban communities to the level of stormwater management.Community resilience is a disaster prevention and mitigation capability based on community resources.In order to solve the deficiency of storm and flood management in the current construction of resilient communities in China,it is necessary to establish a quantitative evaluation system to evaluate it.This paper uses the analytic hierarchy process and Delphi method to establish a community resilience evaluation system from the perspectives of community material space level,community management level and individual level.Then three communities in Hefei City,Anhui Province are selected for practical application of the system,and corresponding optimization and transformation strategies are proposed.The results show that:(1)The resilience of community stormwater management is closely related to the integrated environment of the community,the allocation of flood control facilities and the daily disaster prevention and mitigation management;(2)The ability of disaster prevention and mitigation and the awareness of public participation of the residents in all communities are relatively weak,and the communities invest less in the popularization of stormwater management wisdom;and(3)Resilient communities should not only pay attention to the construction of non-engineering disaster prevention measures,but also to the application of small-scale green infrastructure oriented toward stormwater management.
文摘The positive role of urban green stormwater infrastructure(GIS)and wetland park construction in the process of“sponge city”construction is analyzed by expounding the connotation and problems of“sponge city”construction.Through the analysis of relevant cases,the realization approaches of combing different types of GIS with wetland park landscape design are interpreted,and it is pointed out that different types of GIS can guide the further practice of“sponge city”construction.
文摘INTRODUCTION Humans and plants depend on an adequate supply of clean water for numerous reasons,from food production to sustaining terrestrial and aquatic life.The average Virginia resident uses about 47 gallons(178 L)of fresh water daily(VDEQ 2008).While a majority of Virginians are provided water from a centralized,public utility,there are nearly two million Virginia residents who depend on well water as their main source(VDH 2008).Replenishing groundwater withdrawals depends on recharge(water moving from the surface to groundwater)from infiltration of precipitation through permeable surfaces in the environment;an important part of the hydrologic,or water,cycle(VDEQ 2010).Forests and grasslands provide much of the available recharge area due to their high capacities to infiltrate precipitation.However,the urbanization process is rapidly converting forested areas and grasslands to commercial,residential,or industrial developments.This conversion creates a significant increase in impervious surfaces such as concrete,asphalt,building roofs,and even compacted vegetated sites(U.S.EPA 2003).Impervious surfaces decrease infiltration and groundwater recharge.They also generate increases in stormwater runoff;defined as any precipitation from a rain or snow event that flows off of an impervious surface.As water runs off urban impervious surfaces,it picks up sediment,oils,debris,nutrients,chemicals,and bacteria.The runoff is then collected in a conveyance system,transported,and discharged to surface waters such as creeks and rivers;most of the time without any type of water quality treatment(U.S.EPA 2003;Paul and Meyer 2001).In addition to carrying pollutants,the runoff is also typically warmer than the receiving surface waters.The increased volume and velocity of the stormwater runoff erodes soil and stream channels and can lead to stream“blow out.”Water quality is degraded and aquatic habitats are adversely altered(Meyer,et al.2005,Booth and Jackson 1997).Due to the interconnected nature of watersheds,the degraded water travels downstream causing subsequent problems.The effect of increased development is an increase in stormwater runoff and associated pollutants into surface waters and a decrease in infiltration for groundwater recharge and stream base flows.Traditional practices for mitigating stormwater runoff impacts have targeted the management of peak runoff by using storage facilities such as detention and retention ponds.Mounting evidence that these methods are inadequate prompted the National Research Council in 2008 to advocate a shift to Low Impact Development(LID)practices to better meet stormwater quality and quantity management goals.LID is based on a set of techniques used in Prince Georges County,Maryland(Prince Georges County 1999).LID seeks to restore the natural hydrology of a site by minimizing the creation of impervious surfaces and increasing infiltration of runoff volume.The ineffectiveness of conventional management approaches and the implementation of the Chesapeake Bay and other critical watershed Total Maximum Daily Loads(TMDLs)caused Virginia to revise its entire process for regulating stormwater.LID and Environmental Site Design(ESD)practices are now used to design sites to meet hydrologic goals and to treat runoff to meet a net site nutrient export standard(Battiata et al.2010).As of the date of this paper,15 of these best management practices,or BMPs,have been approved for use by Virginia(Virginia Stormwater BMP Clearinghouse 2011).Similar approaches are being considered and adopted in other Chesapeake Bay jurisdictions,as well as nationally.The responsibility of stormwater management can be fragmented between state,local,and municipal government(Roy,et al.2008),often differing from watershed to watershed.Because LID is decentralized,it changes the management focus from a large,regional scale to a site scale.Changes at the residential lot level can generate much greater infiltration over the watershed.Each homeowner can significantly reduce the stormwater load leaving their property,thereby improving surface water quality and helping to recharge groundwater reserves.From a green building perspective,LID techniques can provide a substantial credit under the LEEDS-ND(Leadership in Energy and Environmental Design-Neighborhood Development)program.The objective of this paper is to provide a relative context for runoff at the site scale,and an overview of the available BMPs that may be applicable.
基金supported by the National Key Research and Development Program of China under Grant 2016YFC0701001.
文摘China started a Sponge City program to offset the adverse impacts of urban developments and to tackle many water-related problems.By emphasizing stormwater management practices with“natural solutions”,many positive results have been achieved.The operation and maintenance(O&M)of Sponge City to support long-term success gained considerable focus.China is facing challenges many developed countries have encountered,as well as unique ones due to specific social,economic,and environmental conditions.This study identified and discussed Sponge City O&M challenges:(1)scheduling challenges,(2)technical challenges,(3)in short of local regulation/ordnance,(4)inadequate O&M assessment standard,(5)underprovided training,(6)PPP related concerns,(7)inter-agency coordination needs,(8)ownership and responsible party issues,(9)substandard documentation,and(10)funding and financial concerns.Selected cases and progress in pilot cities are introduced in the discussions.
文摘Gross pollutants are the primary targeted pollutants in urban catchment management for urban water quality improvement as well as mitigation of flood. Apart from aesthetically unattractive because of its visibility, gross pollutants also contributes to degradation of river water quality and loss of aquatic habitat as it carries harmful pollutants such as oxygen demanding material, hydrocarbons and heavy metals. This study analyzed trend of gross pollutant generated from two urban residential areas located in Selangor, Malaysia. The median value of gross pollutant load obtained fi'om the Amanah Apartment and Bandar Botanic are 347.41 kg/ha/year and 32.46 kg/ha/year, respectively. Relationship between gross pollutant wet load with rainfall depths was derived using regression equation. A significant trend of increasing gross pollutant wet load into drainage system with increasing rainfall depth was observed. The behavior of pollutant load is related to the one observed in Australia.
基金supported by the National Science and Engineering Research Council of Canada(RGPIN-2022-04352)
文摘Many cities are adopting low impact development(LID)technologies(a type of nature-based solution)to sustainably manage urban stormwater in future climates.LIDs,such as bioretention cells,green roofs,and permeable pavements,are developed and applied at small-scales in urban and peri-urban settings.There is an interest in the large-scale implementation of these technologies,and therefore assessing their performance in future climates,or conversely,their potential for mitigating the impacts of climate change,can be valuable evidence in support of stormwater management planning.This paper provides a literature review of the studies conducted that examine LID function in future climates.The review found that most studies focus on LID performance at over 5 km2scales,which is quite a bit larger than traditional LID sizes.Most paper used statistical downscaling methods to simulate precipitation at the scale of the modelled LID.The computer model used to model LIDs was predominantly SWMM or some hybrid version of SWMM.The literature contains examples of both vegetated and unvegetated LIDs being assessed and numerous studies show mitigation of peak flows and total volumes to high levels in even the most extreme climates(characterized by increasing rainfall intensity,higher temperatures,and greater number of dry days in the inter-event period).However,all the studies recognized the uncertainty in the projections with greatest uncertainty in the LID’s ability to mitigate storm water quality.Interestingly,many of the studies did not recognize the impact of applying a model intended for small-scale processes at a much larger scale for which it is not intended.To explore the ramifications of scale when modelling LIDs in future climates,this paper provides a simple case study of a large catchment on Vancouver Island in British Columbia,Canada,using the Shannon Diversity Index.PCSWMM is used in conjunction with providing regional climates for impacts studies(PRECIS)regional climate model data to determine the relationship between catchment hydrology(with and without LIDs)and the information loss due to PCSWMM’s representation of spatial heterogeneity.The model is applied to five nested catchments ranging from 3 to 51 km2and with an RCP4.5 future climate to generate peak flows and total volumes in 2022,and for the period of 2020–2029.The case study demonstrates that the science behind the LID model within PC stormwater management model(PCSWMM)is too simple to capture appropriate levels of heterogeneity needed at larger-scale implementations.The model actually manufactures artificial levels of diversity due to its landuse representation,which is constant for every scale.The modelling exercise demonstrated that a simple linear expression for projected precipitation vs.catchment area would provide comparable estimates to PCSWMM.The study found that due to the spatial representation in PCSWMM for landuse,soil data and slope,slope(an important factor in determining peak flowrates)had the highest level of information loss followed by soil type and then landuse.As the research scale increased,the normalized information loss index(NILI)value for landuse exhibited the greatest information loss as the catchments scaled up.The NILI values before and after LID implementation in the model showed an inverse trend with the predicted LID mitigating performance.
基金jointly supported by the COLABIS project(Collaborative Early Warning Information Systems for Urban Infrastructures,Grant No.:03G0852A)Managing Water Resources for Urban Catchments project in the framework of the Sino-German“Innovation Cluster Major Water”(Grant No.:02WCL1337A-K)funded by German Federal Ministry of Education and Research(BMBF).
文摘Continuous urbanization over the last few years has led to the increase in impervious surfaces and stormwater runoff.Low Impact Development(LID)is currently receiving increased attention as a promising strategy for surface runoff management.To analyze the performance of LID practices for surface runoff management,a longterm hydrological modeling from 2001 to 2015 along with a cost-effectiveness analysis were carried out on a campus in Dresden,Germany.Seven LID practices and six precipitation scenarios were designed and simulated in a Storm Water Management Model(SWMM).A cost-effectiveness analysis was conducted by calculating the lifecycle costs and runoff removal rate of LID practices.Results demonstrated that the LID practices significantly contributed to surface runoff mitigation in the study area.The LID performance was primarily affected by the length of the precipitation scenarios and LID implementing schemes.The runoff removal rate of the LID practices fluctuated significantly when the rainfall scenario was shorter than 12 months.When the rainfall scenario exceeded 1 year the effects on the runoff removal rate was constant.The combination of an infiltration trench,permeable pavement,and rain barrel(IT+PP+RB),was the best runoff control capacity with a removal rate ranging from 23.2% to 27.4%.Whereas,the rain barrel was the most cost-effective LID option with a costeffectiveness(C/E)ratio ranged from 0.34 to 0.41.The modeling method was improved in this study by conducting long-term hydrological simulations with different durations rather than short-term simulations with single storms.In general,the methods and results of this study provided additional improvements and guidance for decision-making process regarding the implementation of appropriate LID practices.
文摘Stimulated by the recent USEPA's green stormwater infrastructure (GSI) guidance and policies, GS1 systems have been widely implemented in the municipal area to control the combined sewer overflows (CSOs), also known as low impact development (LID) approaches. To quantitatively evaluate the performance of GSI systems on CSO and urban flooding control, USEPA-Stormwater Management Model (SWMM) model was adopted in this study to simulate the behaviors of GSI systems in a well- developed urban drainage area, PSW45, under different circumstances. The impact of different percentages of stormwater runoff transported from impervious surfaces to the GSI systems on CSO and urban flooding control has also been investigated. Results show that with current buildup, GSI systems in PSW45 have the best performance for low intensity and short duration events on both volume and peak flow reductions, and have the worst pertbrmance tor high intensity and long durataon events. Since the low intensity and short duration events are dominant from a long-term perspective, utilizing GSI systems is considered as an effective measure of CSO control to meet the long-term controlstrategy for PSW45 watershed. However, GSI systems are not suitable for the flooding control purpose in PSW45 due to the high occurrence possibility of urban flooding during or after high intensity events where GSI systems have relatively poor performance no matter for a short or long duration event,
文摘Urban underlying surface has been greatly changed with rapid urbanization, considered to be one of the major causes for the destruction of urban natural hydrological processes. This has imposed a huge challenge for stormwater management in cities. There has been a shift from gray water management to green stormwater management thinking. The green stormwater infrastructure (GSI) is regarded as an effective and cost-efficient stormwater management eco-landscape approach. China's GSI practice and the development of its theoretical framework are still in the initial stage. This paper presents an innovative framework for stormwater management, integrating green stormwater infrastructure and landscape security patterns on a regional scale based on an urban master plan. The core concept of green stormwater infrastructure eco-planning is to form an interconnected GSI network (i.e., stormwater management landscape security pattern) which consists of the location, portion, size, layout, and structure of GSI so as to efficiently safeguard natural hydrological processes. Shanghai Lin- gang New City, a satellite new town of Shanghai, China was selected as a case study for GSI studies. Simulation analyses of hydrological processes were carried out to identify the critical significant landscape nodes in the high- priority watersheds for stormwater management. GSI should be planned and implemented in these identified landscape nodes. The comprehensive stormwater manage- ment landscape security pattern of Shanghai Lingang New City is designed with consideration of flood control, stormwater control, runoff reduction, water quality protec- tion, and rainwater utilization objectives which couldprovide guidelines for smart growth and sustainable development of this city.
文摘In planning the George W.Bush Presidential Center in Dallas,Texas,former First Lady Laura Bush presented a very clear vision of what the Center should epitomize:“Because George was the first president of the new millennium,I wanted it to be forward and modern.”1 For the president and Mrs.Bush this meant making the building and landscape environmentally responsible,beautiful,and welcoming.In particular,their love of native Texas landscapes was an important framework for transforming the project’s urban site into a park that was sustainable and experientially rich for visitors.Sustainability was addressed from the start with smart planning that privileged contiguous parkland over impermeable surfaces and structures.Simultaneous consideration of every landscape component—-stormwater,plants,soil,topography,and more—netted cohesive natural systems that are better able to succeed with short-term establishment and provide enduring long-term health,the ultimate goals for a sustainable landscape.
文摘Kansas State University(KSU)is a land-grant institution,with nine colleges and 23,000 students.The 668-acre main campus is located within the City of Manhattan,Kansas,which has a population of approximately 45,000.Through a bottom-up process the university has been seeking to integrate sustainability in student life,curriculum,operations,research,and engagement.
文摘This paper presents an approach described as“non-traditional”for restoring water quality and ecosystem services that have been degraded as a result of excess nitrogen.It focuses on emerging technologies often referred to as green infrastructure.These technologies may provide cost effective alternatives to traditional,gray infrastructure such as sewering and is likely to provide significant co-benefits including the creation of local jobs,the preservation of real estate values,and habitat enhancement.The paper focuses on the Three Bays estuary on Cape Cod to illustrate the benefits and potential of green infrastructure technologies.The Three Bays estuary is presented as a case study and as a representative example of implementation of the broader Cape Cod Water Quality Management Plan Update(208 Plan Update)-a nationally-recognized watershed planning project designed to provide a pathway for the fifteen towns of Cape Cod to achieve compliance with Section 208 of the Clean Water Act.The Three Bays estuary and embayment system is a scenic Cape Cod bay that hosts sailing,kayaking,swimming and shellfishing and is located in the Town of Barnstable.It is comprised of three primary segments that include West Bay,North Bay and Cotuit Bay.Sub-systems include Prince Cove that flows into North Bay,the Narrows that flows between North Bay and Cotuit Bay and Eel Pond that flows into East Bay(see Figure 1).The Massachusetts Estuaries Project(MEP)is a state-sanctioned watershedmodeling project that assesses the conditions of the state’s estuaries and required restoration goals.Its technical report(2006)indicates that the water quality of the Three Bays system has resulted in seriously degraded to moderately degraded habitat.The system is listed as an impaired water body on the US Environmental Protection Agency(EPA)303d list of impaired waters.An approved Total Maximum Daily Load(TMDL)for nitrogen has been established for the embayment.This assessment is supported by more recent empirical water quality data collected within the embayment.The more current data documents a continuing decline in water quality with more common algae blooms(see Figure 2).
文摘The Centre of Excellence at Okanagan College in Penticton,British Columbia is being designed as one of the most innovative and sustainable post-secondary facilities in the world.On schedule for design and construction to be complete by April 2011,the two-storey multi-purpose facility has a mandate to provide trades and technology training and professional development to students from the province of British Columbia and beyond.It is aimed at attaining the highest standard of sustainable building design,the Living Building Challenge.The building will support a syllabus with a focus on the design,installation,and support of sustainable building technologies and processes,and the development and application of alternative and renewable energy.The building itself will become an essential element of the educational programs that will reside there,a teaching tool for education on building trades and engineering technologies.In addition,the Okanagan Research Innovation Centre will be incorporated into the building,providing opportunities for start-up companies to develop and prototype new green technologies in a supportive and synergistic environment.This article will demonstrate that a project with this level of sustainable objectives is achievable at a cost comparable to conventional building design.It will address how this can be attained through an integrated design process,along with the numerous innovative features that have been incorporated into the building design to help it function with a small environmental impact,and a large educational one.
文摘Higher education institutions are implementing environmentally friendly practices as never before.According to a 2009 survey undertaken by the Sustainable Endowments Institute,a nonprofit organization based in Cambridge,Massachusetts,more than 300 colleges and universities have become greener over the past few years despite tighter budgets and widely fluctuating energy costs.Three-quarters of these schools have adopted green building policies and about 44 percent have at least one LEED-certified building or are in the process of constructing one.Emory University in suburban Druid Hills outside Atlanta,Georgia,is one of the more forward-looking of these institutions.In 2005,university president James Wagner began the greening of the 600-acre campus by forming a committee to develop an environmental agenda for guiding the institution’s future.The following year,Emory opened an Office of Sustainability Initiatives to implement this policy.The university’s long-term goals include reducing campus energy use by 25 percent per square foot and food,materials,and electronic wastes by 65 percent per square foot—all by 2015.Already,the installation of water-saving fixtures and irrigation in accordance with drought restrictions helped to reduce water consumption by 12 percent between 2007 and 2009.As part of its eco-friendly policy,Emory now requires all new structures on campus to earn a LEED silver rating from the U.S.Green Building Council.So far,the university has achieved LEED certification of 13 buildings on campus—5 gold,5 silver,and 3 certified,including classroom,administrative,research,and healthcare facilities.In addition,six completed or nearly completed buildings are awaiting LEED certification.Ayers Saint Gross Architects and Planners of Baltimore helped to boost the sustainability at Emory,beginning in 1998 with a master plan for the campus.The firm updated this strategy in 2005 just as the university began studying ways of becoming greener.Responding to this mandate,the plan called for native plantings and recycling receptacles on campus,and rerouting vehicular traffic away from the university core,among other environmentally sensitive measures.Ayers Saint Gross has gone on to complete four,eco-friendly buildings at Emory.Each design conveys a distinctive architectural identity through varied types of metal panels and fenestration patterns.At the same time,the buildings’red-tiled roofs and exteriors of stucco and stone harmonize with the historic architecture originally designed by Beaux-Arts architect Henry Hornbostel at the heart of the campus.These new structures include a mixed-use building housing the university’s admissions office,a bookstore,and a café.A green roof is positioned over the parking garage connected to this building.Rainwater is collected in tanks below grade for irrigating the site.More sophisticated are the rainwater harvesting and graywater recycling systems devised by Ayers Saint Gross for two of three freshman residence halls designed by the firm.These green measures are particularly well suited to residence halls as they capitalize on constant water usage in the buildings through toilets,sinks,showers,and laundry facilities.At the same time,they educate the students as to the merits of sustainable design by making visible the process of collecting and recycling water from inside and outside the residence halls.