Melbourne, the capital of Victoria Australia leads the world in having the highest quality drinking water. The Victorian State Government has set targets for reducing per capita water consumption by 15%, 25% and 30% by 2010, 2015 and 2020 respectively and has announced stringent water restrictions to curtail water demand. In this resource constraint environment it is opportune to look for alternative sources of water to supplement Melbourne's traditional water supply. In Melbourne, legislation has been changed to make it possible to use rainwater harvested from domestic tanks for non potable purposes. The annual rainfall in Melbourne's metropolitan area varies from 450mm in the West to 850mm in the East to over 1000mm in the North East mountain ranges. The objectives of the current study are to develop a methodology to estimate the optimal size of the rainwater tank at a particular location considering the local rainfall, roof area, demand for water and the reliability of supply (supply security) required; to quantify the rainwater volume that could be harvested at site using domestic rainwater tanks to minimise pressure on the potable water supply secured from traditional catchment sources until the desalination plant is commissioned in 2013; to analyse the efficacy of rainwater tanks to reduce the stormwater runoff and improve the quality of the stormwater that will otherwise flow into urban drains and to estimate the cost effectiveness ratio and payback period of inst alling rainwater tanks. A simple water balance model was developed to calculate the tank size based on daily rainfall, roof area and the expected demand. The concept of 'reliability' was introduced to measure supply security. Rainfall data from 20 rainfall stations scattered around Melbourne were used to determine the variation in the rainwater tank size dependent on the above stated parameters. It was observed that to achieve the same supply reliability (90%) and to meet a specific demand (toilet and garden use), the tank size required in the western side of Melbourne is as high as 7 times as that required in the north-east side. As a result, the

This research explored the use of development charges (DCs) as a sustainable planning policy implementation tool to address integrated urban water management (IUWM) principles through the implementation of water sensitive urban design (WSUD) practices. This was accomplished by focusing on whether and how development charges can be used in Canadian slow-growth city regions to provide incentives for sustainable urban infrastructure practices through facilitating the decentralisation of stormwater management. The forms of stormwater management explored included structural landscape- and building- based strategies encompassing bioretention, infiltration, and dispersion. Potential implications were explored from the perspective of planning through semi-structured interviews, to the on-the-ground site design level within development projects through a review of the literature and case study analysis. Findings from the National Capital Region (Ottawa and environs) case study were synthesised into a series of best management practices for implementation of an IUWM DC strategy for the Manitoba Capital Region.

Extensive research has been undertaken to improve the robustness of runoff quantity predictions for urban catchments. However, equally robust predictions for runoff quality have yet to be attained. Past studies addressing this issue have typically been confined to the use of simple conceptual or empirical models which forgo the tedious steps of providing a physical representation of the actual system to be modelled. Consequently, even if the modelling results for the test catchments are satisfactory, the reliability and applicability of these models for other catchments remain uncertain. It is deemed that by employing process-based, deterministic models, many of these uncertainties can be eliminated. A lack of understanding of the hydrological processes occurring during storm events and the absence of good calibration data, however, hamper the advancement of such models and limit their use in the field. This research proposes that the development of a hydrologic model based on the kinematic wave equations linked to an advection-dispersion model that simulates pollutant detachment and transport will improve both runoff quantity and quality simulations and enhance the robustness of the predictions. At the very worst, a model of this type could still highlight the underlying issues that inhibit models from reproducing the recorded historical hydrographs and pollutographs. In actual fact, this approach has already been applied by various modellers to simulate the entrainment of pollutants from urban catchments. Also, the paradigm shift to using the Water Sensitive Urban Design (WSUD) approach in designing urban stormwater systems has prompted the need to differentiate the various sources of pollutants in urban catchments such as roads, roofs and other impervious surfaces. The primary objective of the study reported herein is to model runoff quantity and quality from small urban catchments, facilitated by the procurement of the necessary field data to calibrate and validate the model via implementation of a comprehensive field exercise based in Sydney. From a water quality perspective, trace metals were selected as the foci. The study outcomes include the formulation of a linkage of models capable of providing accurate and reliable runoff quantity and quality predictions for the study catchments by taking into consideration: - The different availability of pollutants from urban catchments, i.e. roads vs. roofs; - The build-up characteristics of pollutants on the distinct urban surfaces and their spatial distribution; - The contribution of rainwater to urban runoff pollution; - The partitioning of pollutants according to particulate bound and dissolved phases; - The respective role of rainfall and runoff in the detachment and entrainment of pollutants; - The influence of particle properties such as particle size distribution and density on pollutant transport; and - The relationship associating particulate bound metals to suspended solids. The simulation results obtained using the proposed model were found to be suitable for modelling the detachment and transport of pollutants for small urban catchments. Interpretation of these results reveals several key findings which could help to rectify shortcomings of existing modelling approaches. Even though the robustness of the model presented here may not translate into a significant improvement in the overall robustness of model predictions, the physical basis on which this process-based model was developed nevertheless provides the flexibility necessary for implementation at alternative sites. It is also shown that the availability of reliable runoff data is essential for implementation of the model for other similar urban catchments. In conclusion, the proposed model in this study will serve as a worthy tool in future urban catchment management studies.

Climate change presents us with greater and greater challenges and stormwater is an important part of our future water problems. In some parts of the world the increase and intensification in precipitation causes strain on existing infrastructure while, in others, draughts are becoming more and more severe. Handling stormwater sustainably does not only gain the environment by controlling pollutant spreading, helping with flooding control and water reuse but can also have added values in urban areas if included in urban planning. Implementing green infrastructure and sustainable stormwater solutions creates jobs and are in many countries seen as the future way of handling stormwater. There are many different techniques and ways of adopting sustainable stormwater handling depending on the local problem and physical as well as economic conditions. Together they all have in common of creating added values when implemented. Increased biodiversity, improved air quality, reduced noise, improved growing conditions for urban trees and aesthetical values that have a positive effect on human health are just some of the positive added values of sustainable stormwater handling. The case study in this report concerns a new development on a peninsula in the municipality on Nacka, Stockholm. The recommendation is to adopt the approach of many small solutions that combines to a sustainable way of handling stormwater that not only solves the problem but creates added values in the living and working area. Stormwater is a resource that should be used as one in order to have sustainable urban planning.

The overarching goal of this research is to establish a successful forum for a transition from the existing paradigm of managing wastewater infrastructure to a more sustainable paradigm that achieves a more efficient utilisation of wastewater assets. A transitioning approach to support a more efficient utilisation of surface water and wastewater assets and infrastructure is proposed and developed. The determined transitioning approach possesses key stages namely developing the arena, developing the agenda, case study, and monitoring. The case study stage investigates a drainage utility identifying their improvement drivers, the removal of surface water through detailed drainage modelling and the financial examination of the costs incurred under the various scenarios conducted. Understanding the implications of removing/attenuating surface water from the network is improved through obtaining data by detailed drainage modelling. Infoworks software is used to investigate and assess the current and future operational scenarios of a wastewater system operating over one calendar year. Modelling scenarios were conducted removing surface water from selected areas focusing on the volumes requiring pumping and durations of pumping station(s) operation prior to treatment during storm conditions. The financial implication of removing surface water in combined sewer systems is examined in three main components. Firstly the costs of electricity incurred at the single sewage pumping station (SPS) investigated during the various scenarios modelled require to be addressed. Secondly the costs to retrofit sustainable urban drainage system (SUDS) solutions needs to be identified. Thirdly the implications of removing surface water for the drainage utility at the national level and the potential saving for householder’s committing to a surface water disconnection rebate scheme. When addressed at the macro level i.e., with over 2,100 pumping stations, some operating in sequence and contained within one drainage utility annually treating 315,360 megalitres the significance of the same multiple quantifiable and intangible benefits becomes amplified. The research aims, objectives and findings are presented to the identified and convened stakeholders. The transitioning approach developed encourages positive discourse between stakeholders. The level of success of the transitioning approach determined is then tested using a quantitative methodology through the completion of questionnaires. From the questionnaires completed the respondents unanimously agreed that surface water flows should be removed as well as reduced from the combined sewer system. The respondents agreed that the removal of surface water from a typical combined sewer system is justified by applying a transitioning approach focusing on the energy consumption required to pump increased volumes during storm events. This response is significant based upon the economic evidence and is contrary to the respondents previous position that finance was their most influencing factor. When provided with other potentially available benefits the respondents were even more supportive of the justification to remove surface water from the combined sewer system. The combined findings of the work presented in this thesis provide further justification that the transitioning approach applied to the removal of surface water from a typical combined sewer system, as determined in this research has been successful.