A preliminary feasibility study for a backup water supply-coastal reservoir in Southeast Queensland, Australia

Australia is the driest country in the world, and the lower Murray–Darling Basin and Adelaide have experienced extreme water scarcity crisis, especially during the Millennium Drought (2000–2010). Many counter measures have been proposed or implemented like desalination plants and water buyback, etc., some progress has been made, but far away from a complete solution. Different from existing measures, this research aims at using coastal reservoir technology to shift from upstream water development to downstream development, in order to solve a series of water supply and ecological environment problems by redesigning a coastal reservoir in the downstream area. It is suggested that high-quality water is stored in a “coastal reservoir” inside the Alexandrina Lake for Adelaide’s water supply. The lake water outside the “coastal reservoir” is used for agricultural development. A preliminary feasibility study was conducted in terms of water quantity and water quality, river’s environmental flow and agricultural output. The results show that if a small size (550–630[Formula: see text]GL) coastal reservoir was created inside the Lake Alexandrina in the mouth of Murray River, the Adelaide’s water supply could be secured and its water quality be improved even during droughts like the Millennium Drought. Besides, if the agricultural development is concentrated around the lake, its water demand can be fully met from the lake, rather than the river, thus the agricultural development has little negative impacts on the river’s ecosystem, it is a win-win solution for agricultural development and river ecosystem. It is suggested that Australian government should provide stimulus package for upstream farmers to relocate to areas around the lake.

Energy Implications of Water Management in Cities

Between 1999 and 2007, several successive years of severe drought put South East Queensland's water supply under immense pressure. The decision was taken in 2005 to build a seawater desalination plant and three water recycling advanced treatment plants as part of a large investment plan to secure the region's potable water supply. The infrastructure built and commissioned in the past 3 years has a combined capacity producing more than 350,000 m3 per day of very high quality water that can be used either directly (seawater desalination) or indirectly (recycled water) for supplying drinking water. All the plants primarily rely on reverse osmosis membranes for water purification which is an effective and reliable barrier to contaminants, but also requires high energy consumption and a high level of pre-treatment and chemicals. In this paper, the actual energy consumption of two of the plants (the seawater desalination plant and one water recycling plant) was investigated with the perspective of drinking water production over the July 2009–June 2010 period. Eolia™ Potable Water, a Life Cycle Analysis tool developed by Veolia Environnement Research & Innovation, was used to model the processes and estimate the greenhouse gases (GHG) emissions from both plants. As expected, the energy requirement of the desalination was higher (approximately 2.2 times) than the water recycling plant. The plants were found to be significantly more energy efficient when operated at higher flow. In both cases, the purchase of electrical energy represented by far the major contribution to GHG emissions. Indirect GHG emissions from chemical consumption could be reduced at the water recycling plant by optimising the dose of ferric chloride used at the plant and sourcing the chemical from a less distant supplier.

Examining the potential for energy-positive bulk-water infrastructure to provide long-term urban water security: A systems approach

Life-cycle energy impacts for adapting an urban water supply system to droughts

Cities around the world are increasingly involved in climate action and mitigating greenhouse gas (GHG) emissions. However, in the context of responding to climate pressures in the water sector, very few studies have investigated the impacts of changing water use on GHG emissions, even though water resource adaptation often requires greater energy use. Consequently, reducing GHG emissions, and thus focusing on both mitigation and adaptation responses to climate change in planning and managing urban water supply systems, is necessary. Furthermore, the minimization of GHG emissions is likely to conflict with other objectives. Thus, applying a multiobjective evolutionary algorithm (MOEA), which can evolve an approximation of entire trade‐off (Pareto) fronts of multiple objectives in a single run, would be beneficial. Consequently, the main aim of this paper is to incorporate GHG emissions into a MOEA framework to take into consideration both adaptation and mitigation responses to climate change for a city's water supply system. The approach is applied to a case study based on Adelaide's southern water supply system to demonstrate the framework's practical management implications. Results indicate that trade‐offs exist between GHG emissions and risk‐based performance, as well as GHG emissions and economic cost. Solutions containing rainwater tanks are expensive, while GHG emissions greatly increase with increased desalinated water supply. Consequently, while desalination plants may be good adaptation options to climate change due to their climate‐independence, rainwater may be a better mitigation response, albeit more expensive.

Optimal sequencing of water supply options at the regional scale incorporating alternative water supply sources and multiple objectives

Greenhouse gas emissions are likely to rise faster than growth in population and more than double for water supply and wastewater services over the next 50 years in South East Queensland (SEQ), Australia. New sources of water supply such as rainwater tanks, recycled water, and desalination currently have greater energy intensity than traditional sources. In addition, direct greenhouse gas emissions from reservoirs and wastewater treatment and handling have potentially the same magnitude as emissions from the use of energy. Centralized and decentralized water supply and wastewater systems are considered for a scenario based upon a government water supply strategy for the next 50 years. Many sources of data have large uncertainties which are estimated following the IPCC Good Practice Guidelines. Important sources of emissions with large uncertainties such as rainwater tanks and direct emissions were identified for further research and potential mitigation of greenhouse gas emissions.

Next to air, fresh water has been always considered as the most important resource, central to economic development as well as to human physiological needs. Currently the total world population is about 7 billion, and, by 2050, it is projected to be 9 billion. By that time an additional 40 Nile Rivers will be needed. Historically, inland dams have successfully solved the water deficit problems in many places, but more and more countries are resorting to emerging technologies like desalination, wastewater recycling and rainwater tanks which are needed to replace inland dams for a number of geomorphological, environmental and societal reasons. These new technologies require a paradigm shift in the water supply industry: global water consumption is only 5~6% of annual runoff—as it is in Australia—so the coming shortage is not of water, but of storage. A coastal reservoir is a reservoir designed to store floodwaters in a seawater environment. The first generation of this technology has been successfully applied in China, Singapore, Hong Kong and Korea, but the water quality is generally not as good as that from inland reservoirs. The second generation of coastal reservoirs has been developed and its water quality is comparable with the water available from conventional urban water supply reservoirs. The conceptual design of coastal reservoirs for Australia’s capital cities is outlined.

New large dam construction is a worldwide problem due to its negative impacts on the ecosystem, and as a result, it is crucial to investigate the future water supply infrastructures. After comparison with the existing solutions for water supply, such as inland reservoirs, desalination plants and wastewater reuse facilities, we conclude that coastal reservoir will be the dominant solution in the future because: a) increasing numbers of people migrate towards coastal/deltaic regions and more megacities are emerging along the coastline; consequently the water shortage on the coastline is the most severe; b) the future water deficit is huge (about 10 times the flow of the Nile river), with no solution other than the implementations of coastal reservoirs, freshwater reservoirs in the seawater to develop runoff from rivers, able to provide so much water. Now the world only uses 1/6 of total runoff, with the remaining 5/6 of runoff lost to the sea; c) all solutions for water supply have significant impacts on the environment, and only the strategy of using coastal reservoirs is sustainable, as it is without brine as a by-productor high carbon emissions. This paper discusses the supply of water to Beijing and Tianjin, the most notorious region in the world for its thirst. It is found that the water shortage problem in the region can be solved, the efficiency of South-North Water Diversion Project can be improved significantly, and carbon emission can be reduced in the region if this new solution is applied. KeywordsCoastal Reservoir; Inland Reservoir; Water Supply; South-North Water Diversion Project

Mitigating Curtailment and Carbon Emissions through Load Migration between Data Centers

Chapter 11 - Europe water crisis and possible CRs

Seawater desalination is considered a technique with high water supply potential and has become an emerging alternative for freshwater supply in China. The increase of the capacity also increases energy consumption and greenhouse gases (GHG) emissions, which has not been well investigated in studies. This study has analyzed the current development of seawater desalination in China, including the capacity, distribution, processes, as well as the desalted water use. Energy consumption and GHG emissions of overall desalination in China, as well as for the provinces, are calculated covering the period of 2006–2016. The unit product cost of seawater desalination plants specifying processes is also estimated. The results showed that 1) The installed capacity maintained increased from 2006 to 2016, and reverse osmosis is the major process used for seawater desalination in China. 2) The energy consumption increased from 81 MWh/y to 1,561 MWh/y during the 11 years. The overall GHG emission increase from 85 Mt CO2eq/y to 1,628 Mt CO2eq/y. Tianjin had the largest GHG emissions, following are Hebei and Shandong, with emissions of 4.1 Mt CO2eq/y, 2.2 Mt CO2eq/y. and 1.0 Mt CO2eq/y. 3) The unit product cost of seawater desalination is higher than other water supply alternatives, and it differentiates the desalination processes. The average unit product cost of the reverse osmosis process is 0.96 USD and 2.5 USD for the multiple-effect distillation process. The potential for future works should specify different energy forms, e.g. heat and power. Alternatives of process integration should be investigated—e.g. efficiency of using the energy, heat integration, and renewables in water desalination, as well as the utilization of total site heat integration.

One of the assumptions underlying efforts to convert cropping land, especially marginal crop land, to plantations is that there will be a net reduction in greenhouse gas emissions, with a gas “sink” replacing a high energy system in which the breakdown of biomass is routinely accelerated to prepare for new crops. This research, based on case studies in Kingaroy in southeast Queensland, compares the amount of greenhouse gas (GHGs) emissions from a peanut/maize crop rotation, a pasture system for beef production and a spotted gum (Corymbia citriodora) timber plantation. Three production inputs, fuel, farm machinery and agrochemicals (fertilizer, pesticides and herbicides) are considered. The study extends beyond the farm gate to include packing and transportation and the time period is 30 years. The results suggest that replacing the crops with plantations would indeed reduce emissions but that a pasture system would have even lower net emissions. These findings cast some doubt on the case for farm forestry as a relatively effective means of ameliorating greenhouse gas emissions.

This dataset is one of seven datasets that analyses a water supply option in terms of externalities (positive and negative effects that are not taken into account directly in market-place transactions). The water service option covered in this dataset is wastewater recycling, which involves: the harvesting of wastewater from sewage reticulation; transfer to a wastewater treatment plant; treatment; and distribution for specific uses that are dependent on water quality, control measures and available transportation infrastructure. Related datasets cover stormwater harvesting, desalination, dams, groundwater, greywater, and rainwater tanks. Each dataset identifies the social, environmental and economic impacts associated with the option in general and for each stage in its life cycle. Stages generally comprise the collection, storage, treatment, distribution of water and, finally, the decommissioning of the water supply option. The externalities were identified by an extensive survey of existing research and literature in water-related studies and through technical analysis of the option characteristics and technologies. The literature is vast and, at times, contradictory. The data is intended to provide an overview of the externalities that must be considered in the externality evaluation process, and does not provide not definitive values for option impacts as externality impacts will be site-specific.