The management and delivery of water and wastewater consume significant amounts of energy, mostly in the form of electricity. With increasing populations, climate change, water quality issues and increasing energy prices, it is more important than ever to understand energy consumption patterns. Energy usually represents the largest operational cost in water utilities around the world, yet there is limited work aiming to quantify the specific relationship between water and its associated energy, and understand its implications for future decision-making. This thesis presents variousmethodological approachesto quantify and understand energy use in water infrastructure systems, as well as how to incorporate them in decision-making processes. The main hypotheses are as follows: firstly, a detailed understanding of the use of energy in water infrastructure systems can facilitate more efficient and sustainable water infrastructure systems and, secondly, that incorporating energy into planning for water and wastewater resources can help understand the impacts of decisions and establish trade-offs between actions. To test these hypotheses, the thesis presents an analytical approach to various areas. Firstly, it identifies, maps and quantifies the energy consumption patterns within a water infrastructure system. This is then used to identify inefficiencies and areas of potential energy saving. Secondly, it incorporates detailed energy costs into short and long-term water resources management and planning. Thirdly, it evaluates trade-offs between energy costs and changing effluent quality regulations in wastewater resources. The Thames River basin, in the south-east of England, is used as a case study to illustrate the approach. The results demonstrate that a systematic approach to the quantification of energy use in a water infrastructure system can identify areas of inefficiencies that can be used to make decisions with regards to infrastructure planning. For example, water systems have significant geo-spatial variations in energy consumption patterns that can be addressed specifically to reduce negative trade-offs. The results also show that incorporating detailed energy information into long-term water resources planning can alter the choices made in water supply options, by providing more complete information. Furthermore, methodologically, they show how several methodological approaches can be used to support more complete decision-making in water utilities to reduce short and long-term costs. In this particular case study, the results show that there are important differences in energy consumption by region, and significant differences in the seasonal and energy patterns of water infrastructure systems. For example, water treatment was shown to be the largest consumer of energy within the whole system, compared with pumping or wastewater treatment; but wastewater treatment energy consumption was shown to be the fastest growing over time due to changes in water quality regulatory frameworks. The results show that more stringent effluent standards could result in at least a doubling of electricity consumption and an increase of between 1.29 and 2.30 additional million tonnes of CO2 a year from treating wastewater in large works in the UK. These are projected to continue to increase if the decarbonisation of the electricity grid does not occur fast enough. Finally, the thesis also shows that daily energy consumption can be reduced by up to 18% by optimally routing water through a water network. optimization of water networks, and that a change in discount rates could change the daily operating costs by 19%, that in turn leads to a resulting different set of optimal investment options in a water supply network.

In this thesis I discuss how divers in Rio de Janeiro and Arraial do Cabo, Brazil, are part of a process of making water (Barnes 2014). This I do by examining the relationship between the policies of the non-governmental organization Project Aware and these divers. These policies under question concerns the growing issue of marine debris, asking divers to directly act towards a solution by removing debris, and inform about the issue. I employ the concepts habitus and the entrepreneurial self as heuristic think-tools in order to illuminate the structuring aspect of this relationship, how it affects the way policies are negotiated, embodied, and practiced in regard to society and the environment (e.g. Bourdieu 1990; Rose 1998; Gershon 2016). My argument is based on observations, interviews, and media analysis. I show how my interlocutors are engaged in making water, in hands on actions of removing debris, and in discourse making where the issue is forwarded, emphasized, and discussed. Further I illustrate the impact that local power structures hold on practices of agents (Barnes 2014; Karlsson 2015).

Water-resource managers are facing unprecedented challenges in accommodating the large uncertainties associated with climate change in their planning decisions. Integration of climate risk information is a pre-requisite for water resources planning under a changing climate, yet this information is often presented outside the decision-making context and in a way which is not relevant for the decision at hand. Furthermore, there is a lack of approaches that explicitly evaluate the impact of nonstationary climate change on decision-relevant metrics and variables. This thesis describes novel methods for incorporating uncertain information on climate change in water resources decision-making and estimating climate change-related risks in water resources systems. The main hypotheses of this thesis are that: (1) shifting away from planning approaches based on abstract supply-demand balance metrics towards risk-based approaches that quantify the frequency and severity of observable outcomes of concern to water users, such as water shortages, can help decision-makers establish preferences among actions and identify cost and climate risk reduction trade-offs (2) adopting risk-based planning methods allows water managers to characterize and account for different sources of uncertainty in the water planning process and to understand their impact on outcomes of value and decisions. To test these hypotheses, this thesis presents an analytic approach for (1) incorporating nonstationary climate change projections and other uncertain factors related to demand changes into water resources decision-making, (2) understanding trade-offs between benefits of climate risk-reduction and cost of climate change adaptation, and (3) characterizing water supply vulnerability to unprecedented drought conditions. The approach is applied to London's urban water supply system located in the Thames river basin, south-east of England. Results from this thesis demonstrate how a systematic characterization of uncertainties related to future hydro-climatic conditions can help decision-makers compare and choose between a range of possible water management options and decide upon the scale and timing of implementation that meet decision-makers' risk tolerability. Additionally, results show the benefits of combining climate information with vulnerability analysis to test decisions' robustness to unprecedented drought conditions. The application of the proposed methods to the London urban water supply system suggests that the risks of exceeding reliability targets in the future will increase if no further supply or demand side actions were to be taken. Results from the case study also show that changes in demand due to population growth could have greater impacts on water security than climate change and that small reductions in climate-related risk may come at significantly higher costs. It should be stressed that the results from the case study are based on a simplified representation of London's water supply system and that they should be further tested with the full system model employed by the water utility which implements more complex operational rules.

Thesis (Ph. D.)--Salve Regina University, 2006.