Pervious pavements in car parks and driveways reduce peak discharge and the volume of runoff flowing in to urban drains and improve the water quality by trapping the sediments in the infiltrated water. This reduces the risk of pollutants such as suspended solids and particle bound chemicals such as phosphorous, nitrogen, heavy metals and oils and hydrocarbons entering receiving waters. The key objectives of the study are to establish relationships between rainfall and pervious pavement runoff and quantify improvements to infiltrated stormwater quality through the pervious pavement. This paper focuses on presenting results from field tests carried out in Melbourne to evaluate improvements to water quality from stormwater infiltrating through the pervious pavement surface.
In the driest continent on earth, population growth, extended drought conditions and the potential impact of climate change has hammered home the need for an integrated approach to water management. Water authorities, councils, water industry organisations and developers face many challenges in delivering sustainable solutions to urban water management issues associated with stormwater management, water recycling and reuse. One of the most significant challenges is managing the cultural and organisational changes necessary to adopt new ways of thinking and to become leaders in implementing new approaches to sustainable urban water management. The 2005 inaugural winner of the Brian Robinson Fellowship Jacquie White developed the Principles To Practice project, designed to explore socio-organisational issues associated with implementing sustainable water management, and investigate factors that influence effective knowledge building and information sharing. Principles To Practice developed and piloted industry-wide strategic interventions to support the development of young water industry professionals as a group of committed and experienced change agents who understand interpersonal and organisational perspectives as well as the technical aspects of sustainable urban water management and who have the potential to influence and direct change. “Sustainable urban water management is not about finding a definition, it’s about values and ideas, people working together to achieve – sustainability is about the dialogue” Principles to Practice project participant
Sorption is expected to be an important process in nutrient removal from stormwater by bioretention systems. The sorption capacity of loamy-sand media from experimental bioretention mesocosms with and without vegetation and prior nutrient enrichment was tested, using two incubation times (24 hours or 72 hours) and nutrient solutions comprising ammonium, organic nitrogen, phosphate, organic phosphorus, and organic carbon, at concentrations representative of stormwater and higher. At stormwater concentrations, enriched media sorbed none or very little phosphate. When the equilibrium concentrations were calculated for all compounds tested, they revealed that at the concentrations expected in stormwater, nutrients could be expected to desorb from the media to solution rather than be removed from solution. No nitrate was extractable from the vegetated media, whereas considerable quantities were extracted from enriched, non-vegetated media. The presence of vegetation appears to reduce the risk of nitrate leaching from filter media. Sorption is not likely to be a long-term sink for nutrients in stormwater bioretention systems. Its role may be to extend the residence time of nutrients in the media so that plants and microbes have the opportunity to mineralise and assimilate these compounds.
Coupled with the recent recognition of the importance of rainwater harvesting and management (RWHM) to solve many of the world's water problems, the promotion of RWHM is growing rapidly throughout the world. RWHM is believed to have a major role as a type of sustainable infrastructure by enabling developing countries to meet the Millennium Development Goals and as a sustainable technology for developed countries. Despite the severest climate conditions in Korea, the people have survived for thousands of years accumulating knowledge and wisdom in rainwater management, although it is sometimes forgotten or thought to be outdated. In this paper, the old wisdom and practice is revisited through case studies of RWHM from Korean history. A new paradigm is suggested, the main concepts of which are to consider rainwater as the main source of water, to be managed by area on a decentralized basis, to control water near its source, and to involve local action. Several multi-purpose and proactive RWHM practices are introduced where RWHM is used for other benefits such as flood control, disaster prevention, energy saving, and pollution prevention. With this new paradigm, various activities are suggested with the involvement of different stakeholders: research and technology, developing theoretical background and supporting materials for decision makers, education and public awareness, and constructing a worldwide network.
Fine sediments play an important role as a pollutant transport tool in runoff from urban areas. The adsorption of hydrophobic pollutants such as heavy metals to finer particles is of particular concern since adsorption to sediment surfaces is important for the growth and survival of many organisms native to the aquatic environment. Urban stormwater management structural measures generally have limited impact on the removal of fine sediments, especially pre-treatment measures such as gross pollutant traps. This can lead to very high loads of fine sediment reaching secondary treatment such as wetlands and ponds or receiving waters and ultimately lead to significant costs in maintenance and degradation of water quality. This paper will report on a study carried out at the Louisiana State University in the United States where a Continuous Deflective Separation (CDS) unit tested in the field for fine sediment removal. The study found that by carefully choosing screen aperture and introducing secondary flow paths, a relatively high percentage of fine sediments could be removed in the unit. It found that more than 90% of particles above 75mum could be removed as well as 53% of particles in ranging between 25-75mum and up to 43% of particles smaller than 25mum.
Rainwater catchment is commonly thought of as applicable to remote buildings, located on the fringes of civilization.. Such is not the case for buildings located in the cities of the Virgin Islands, Bermuda, and island locations in general. Here, often historic buildings are clustered together and fire protection to avoid major fires is necessary to avoid disaster. Typical of these locations is a limitation of available water to fight a building fire. Utilizing rainwater catchment, to provide the water for a fire suppression sprinkler systems to operate, may provide a solution to the need
The World Health Organization has published the 3d edition of the Guidelines for Drinking Water Quality in late 2004. In May 2007 WHO has reviewed an addendum to the Guidelines on rainwater for human consumption. A stand-alone document on collection and storage of rain water for human consumption is also under preparation. While several countries have national guidelines or standards for water quality of collected rain water used as drinking water source, the growing utilization of rainwater as a potential source of water for human consumption makes it imperative that WHO recognizes rainwater and includes appropriate guidance in the Guidelines for its use. The paper reviews the health risks of rainwater based on an extensive literature review. The assessment considers microbiological and chemical quality, vector control, and technical and environmental situations that may influence the risks. Initial results of the application of water safety plans for rainwater collection and storage systems show promise in enabling households in low-income or water-scarce countries in maintaining domestic water quality.
The present work describes in general way a model of sustainable development applied to small communities, from considering to the water as a development axis. This proposal would be located in the community of Villa Garcia Marquez, Municipality of La Barca, Jalisco Mexico, which comprises the river basin of the Lake of Chapala, which is the most important natural water reservoir of the country and it displays remarkable environmental problems and of over-exploitation at the present time. The community Villa de Garcia Marquez, have an important backwardness in its development mainly because of the lack of fresh water, deforestation, low farming productivity, low quality of urban services and urban image, high migration from men to the United States, that's why women integrated the population mainly, lack of job opportunities and human development. The model would try to promote the results acquired in terms of: sufficient water and of good quality for the human consumption with local solutions and technologies accessible; the generation of communitarian organizations for management and administration of the water at local level; improvement of the urban image and the territorial landscape taking advantage of the stormwater overflows through domestic rainwater catchments systems and retention ponds; generation of job opportunities and self-sufficient businesses in ecological tourism and ecological rural farms; experience for the dissemination in the municipality and the region of the model. In the same way, it deals with to link through an integral vision: the training of the community in the handling of its hydraulic resources; the elaboration and implementation for small projects for conservation, supply and sanitation water; the coordinated participation between community and municipal government in the financing and management of the actions; the linking between civil associations of young people, consulting companies and the University of Guadalajara for the development of technical proposals of integrated water management and its application in urban and productive projects; the improvement of the environment, the territorial landscape and the urban image of the community; as well as the job generation and opportunities for rural business with an ecological tourism direction and sustainable rural development. This project is integrated to the Integral Water Management Plan for the Municipality La Barca, Jalisco Mexico, which is approach to get a planning and efficient hydraulic management of the resource, as much in the urban zones as in the rural ones, orienting them to the sustainable development in the management of the resource and to the water as a detonator axis for the communitarian development.
As part of their commitment to the reduction of nitrogen loads entering Port Phillip, Melbourne Water constructs large scale stormwater treatment systems across metropolitan Melbourne. To date most of the treatment systems have been wetlands. Treatment measures which use filtration through a vegetated sand media obtain higher rates of nutrient removal per unit area than surface flow systems, i.e. wetlands. This has prompted Melbourne Water to consider using a large scale rain garden in a site where a wetland would have traditionally been placed. Ecodynamics were appointed to undertake the design and subsequent construction of the project. The design process required the specification of a treatment train that included a sediment trap, wetland area and rain garden. The rain garden has an area of approximately 3700 m2. A number of issues were faced during the design of the system including design of outlet structures to cope with the volume of water moving through the filter, specification of the filter materials and control of the hydrology of the system. A number of innovations were made to control the hydrology and filter behaviour, many of these findings which will be suitable for other systems. Pollutant export modelling of the treatment train found it was able to provide the same treatment as a wetland at several times larger.
In early 2006, the Victorian Government released the Yarra River Action Plan, which allocated $20 million towards tackling urban stormwater pollution. To ensure this money is allocated in an equitable and transparent manner across all metropolitan local governments a multi-criteria assessment tool has been developed. This paper presents an overview of the multi-criteria assessment tool developed and adopted for selecting structural Water Sensitive Urban Design (WSUD) projects that are eligible for funding through Melbourne Water's Stormwater Programs. This tool considers three types of indicators: environmental, engagement (engagement with stakeholders and local government capacity building), and financial. Within each category, a series of descriptive indicators of different weightings are applied to score a project: an overall score of 0.45 being required for the project to be accepted. Where initial concept designs do not satisfy this criterion, additional work is undertaken to refine and improve the project. The tool and its use are illustrated with a case study.
In this 5 - year study we investigated the microbiological quality of roof-collected rainwater samples of 560 private dwellings in New Zealand. At least half of the samples analysed exceeded the minimal acceptable standards for contamination and 41% of the samples showed evidence of heavy faecal contamination. The likely sources of the faecal contamination were faecal material deposited by birds, frogs, rodents and possums, and dead animals and insects, either on the roofs or in the gutters, or in the water tank itself. Many of the roof water supplies surveyed revealed deficiencies in the use of rainwater catchment systems and components. In a significant number of supplies where we found heavy faecal contamination there was evidence of lack of maintenance; inadequate disinfection of the water; poorly designed delivery systems and storage tanks; and failure to adopt physical measures to safeguard the water against microbiological contamination. The results of this study indicate that the information on the safe collection and storage of roof-collected rainwater seems not to be reaching many users in New Zealand. Roof water users need more information pertaining to their roof water supplies but we believe improvements are necessary in the dissemination of this information.
This paper reports on a water sensitive urban design initiative by an owner builder at a private residence in Ipswich, Australia. The project applies custom, emergent and established technologies to the management of the owners' lifestyle preferences and problematic site conditions. It is also an innovative project from the perspective of current governance conditions, making use of previously untried regulatory mechanisms. The project comprises two integrated components: rainwater harvesting and onsite waste treatment, potentially offsetting household reliance on the mains water supply by as much as 90% and offering further beneficial externalities. Rainwater is harvested from a 135m roof catchment through a conveyance system that includes leaf diverters and screens, though no first flush diverter, to a 15kL PE storage tank. A high performance pump feeds the rainwater successively through a filter and water meter to a Bianco Rainsaver which enables switching between the rainwater supply and mains water back-up. Water is supplied throughout the house via a PE-X water service to every outlet except the kitchen sink. The kitchen sink (plumbed separately) permanently draws from the mains water supply, a necessity with Ipswich City Council regulations. Flow restrictors and AAA (or higher) rated fixtures and fittings are used throughout the home and a 30-tube 315L Endless Solar hot water service is used. All waste water (black and grey water) is processed onsite in an OzziKleen RP10A advanced secondary treatment plant that features custom modifications for this project (due to site conditions, but not affecting system performance). Permission to install the OzziKleen RP10A system was obtained under s4 of the Queensland Plumbing and Wastewater Code 2006, with this project as a test case. The paper presents the author/owner's experience researching, installing and using the various technological components. It addresses problems and resolution of relevant compliance and regulation issues, with conclusions drawn from these experiences. It concludes with plans to operate the site as a non-commercial community education project.
The aim of this paper is to provide an overview of the Italian situation concerning the use of rainwater catchment systems analysing the topic from different points of view. Daily rainfall data from more than three hundred meteorological stations, located homogenously on the Italian peninsular area, were collected and analysed. The efficiency of the rainwater tanks of different volumes in each station was tested. In the analysis, the different conditions were compared taking a typical user as point of reference, characterised by the typical demand of each regional area. To decide the value of demand, the total demand for drinking water was considered first and then the percentage that could be replaced by rainwater was analysed. To deal with the problem from an economic point of view a fundamental step was a research on the inhomogeneous prices of drinking water in Italy, in addition to the study of the cost of the system. Finally, through a questionnaire given to several firms working in the hydraulic installation sector throughout the country, interesting information was gathered on the diffusion of rainwater catchment systems, their use, market conditions and the methods actually adopted to calculate the tank size.
Melbourne's land cover is spatially variable and experiences a strong natural precipitation gradient from west to east. Using precipitation and potential evaporation data, along with land surface characteristics for ten sites across Melbourne, this study investigates spatial differences in evapotranspiration and irrigation demand. Using a water balance model for outdoor water use only, it was found that irrigation demand is largely dependent on the vegetated fraction (gardens and parks) of the sites. Spatial variability of rainfall is also an important factor for predicting irrigation demand. The study proved that large fractions of green space enhance evaporation, but they also result in increased irrigation requirement.
A literature review highlighted a deficiency of information pertinent to the Australian context in regards to rainwater quality and runoff from roof surfaces. In this study, a novel approach has been developed to determine the runoff volumes and pollutant loads from a roof catchment for different storm events. Rainwater samples were also taken. Details of the field monitoring station installed as part of this project and some preliminary results are included herein. The runoff collection system was designed not only to obtain hydrologic data such as rainfall depths and runoff volumes but also to collect runoff samples concurrently, with the data being transmitted in real-time via General Packet Radio Service (GPRS) to an Internet server for storage. Trace metals, being one of the major pollutants in the urban environment are the main focus of the pollutant loads. It was found that the rainwater samples were acidic, with a pH range from 3.77 to 5.63. Rainwater also contributed to the dissolved metals found in roof runoff. High copper concentrations were recorded, suggesting roofing materials as sources of roof runoff contamination. Only particulate Cu experienced first flush in one event. Future work will include obtaining samples from more storm events and identifying the relationships between water quality paramaters.
Biofiltration systems are being installed on an ever-increasing scale, both for stormwater quality improvement and as a component of stormwater reuse systems. However, there is currently a general lack of knowledge regarding their design, implementation and performance. This paper reports on the issues encountered and lessons learnt during the installation and operation of an experimental biofiltration system. While the water industry familiarizes itself with biofiltration technologies, effective communication and clear guidance is required to ensure successful construction and operation of biofilters. The studied biofiltration system consisted of three separate cells, each containing a different, soil-based media type. Compaction of filter media, organic matter and moss growth significantly reduce hydraulic conductivity, however root penetration and the addition of vermiculite and perlite appear to assist in maintaining porosity. Preliminary treatment performance results indicate that all three cells effectively remove sediment and heavy metals (lead, copper and zinc), however they are all net producers of nitrogen and phosphorus. However, biofiltration systems appear to be promising technologies for treatment of stormwater, both for reuse and aquatic ecosystem protection.
To be successful, a project needs a project leader that can push the Water Sensitive Urban Design (WSUD) component through the various challenges a project endures from initial concept to actual implementation on the ground. The ideal leader should be able to gather a multi-disciplinary team around the project, to help break down or effectively work across any potential organisational silos, to deal with any perceived barriers from external organisations and to distribute the responsibilities for project development and implementation. However, management or higher-level support and a dedicated WSUD officer within the council can considerably facilitate the work of the project leader and the acceptance of WSUD into Council projects. The key learning's that the authors have found include having: - Involvement of a multi-discipline project team from the beginning; - Senior management support in WSUD; - Effective engagement, both to internal staff and the community; - A dedicated WSUD project officer may be advantageous for Council, especially in the initial period of WSUD implementation; - Internal procedures for shifting costs between departments will help sustain WSUD implementation in the long run; - Continual capacity building of staff and the industry; - Adequate detailed design; - Pre-construction meeting with relevant people; - Testing the filter material before it is delivered on site; and - Constant site inspections.
A gutter design that optimises self flushing potential is crucial in rain water harvesting at the dwelling scale. Excluding and removing organic debris from a gutter is essential for the maintenance of water quality in water harvesting systems. There are existing debris exclusion products; however the function, performance and suitability of these products is not well understood and application is limited as they require ongoing maintenance. The aim of this study was to determine the water harvesting gutter configuration that minimises the maintenance needs and optimises self flushing. Investigation into the conditions and processes that influence the performance of guarded and un-guarded roofs found that the failure mechanisms of gutter guard products was due to the entrapment of debris (above the guard) and infiltration of decomposed debris. A series of experiments was undertaken to test a set of three hypotheses, regarding the most efficient shape and slope and obstruction threshold . The results support the notion that the semi-circular gutter is the most efficient cross sectional shape for a gutter. Increasing the slope of a gutter increased the bed-load (sediment) transport facility of a gutter, but had a negative effect on the removal of buoyant debris from the gutter. The combination of gutter guard products with accessibility to the 'head' of the gutter and the semi-circular high slope design conditions is likely to provide an effective self flushing and low maintenance gutter.
Management of water-related disasters on the island of Jeju is the most difficult in the world because of the island's environmental characteristics; Jeju Island suffers from flooding and drought simultaneously. There is a limitation to the existing water management plan for mitigation of natural disasters, and a new management plan is needed which will apply to Jeju Island. In this study, we introduce the new paradigm of decentralized rainwater management. The starting point of this new paradigm is that the disasters are local problems. In order to prevent them, it should be dealt under local control. Rainwater management in the new paradigm sets a goal in which water management should be performed at the source not by linear means such as the stream and the drainpipe. Considering the environmental characteristics of Jeju Island, we selected several technologies suitable for decentralized rainwater management and designed systems suitable for group of buildings, roads, streams, mountains, and households. We are suggesting building feasibility methods for the decentralized rainwater management strategies. And we expect to find a solution for the water problem on the Island, as these plans are applied across Jeju Island, and to achieve a good engineering and scientific result.
It is not widely appreciated how innovative Water Sensitive Urban Design (WSUD) intervention strategies can assist in countering the negative effects of deteriorating water infrastructure and evolving urban areas. Deteriorating infrastructure is a problem for the majority of urban centres around Australia and is becoming more important as assets age, populations increase and urban centres expand. These problems generally result in diminishing asset performance and serviceability. This paper provides a discussion of infrastructure deterioration, including some of the specific physical causes of deterioration, and also contrasts current infrastructure practice with innovative WSUD approaches to mitigate the impacts of infrastructure deterioration. A simple case study is presented to demonstrate how traditional infrastructure can be augmented with innovative WSUD approaches to provide significant improvements in the performance of traditional water infrastructure. The computer program PURRS has been used to simulate the effects of water demand management, wastewater reuse and rainwater tanks on mains water supply. This has been done by modelling the lot scale water balance and then determining the water supply characteristics. A discussion on the potential benefits that may be obtained from the combined water cycle asset serviceability is provided which describes how lifecycle costs may be reduced and asset replacements deferred. This paper concludes that it is absolutely necessary to investigate the urban water cycle in a holistic and integrated way in order to provide more optimal outcomes to urban water cycle problems.
