This paper proposes to:
A confluence of factors including population growth and climate change poses significant challenges to the sustainability of cities worldwide. A case study into climate change adaptation and urban water management was undertaken in Wellington, New Zealand, using resilience and complex systems science approaches. Climate change and water demand scenarios for 2040 and 2090 were generated using Greater Wellington’s ‘sustainable yield’ model and downscaled climate model data.
The purpose of freshwater biomonitoring is to provide an indication of a stream’s, river’s, or lake’s health, typically in order to make a connection between a human activity and resulting effects. CPG has been undertaking biomonitoring annually within the Waitangi Stream since 2001 to assess possible impacts of landfill leachate and wastewater discharge originating from the Waiouru Military Camp and settlement. This paper discusses preliminary results from analysis of a seven-year longitudinal biomonitoring study to assess the impacts to Waitangi Stream from these discharge activities. Data was analysed using two approaches including one which examines variations and differences in each individual quantity measured and one which instead analyses the entire data set at once using principal components analysis (PCA).
At 4:35AM on Saturday 4th September 2010, the Darfield earthquake struck in the Selwyn District. The effects of the earthquake on infrastructure have been felt throughout the district both locally and more strongly and recently with the Christchurch aftershock.
Wellington is extremely vulnerable to large earthquakes since it is bisected by large active faults and isolated in terms of supply lifelines. The potential for loss of water and food supplies is real and could render large areas uninhabitable for weeks to months. The purpose of this study was to explore the options for the installation of rainwater tanks in critical areas in the Wellington Region before and after a damaging earthquake. The importance of securing emergency water after a large earthquake is indisputable and this study was especially concerned with the applicability of roof water harvesting as a sustainable alternative water supply option.
This paper will examine some of the tools and techniques used in reservoir tank design around New Zealand, and present some options for incorporation into bulk water storage design for water supply managers.
This report will include water metering initiatives and benefits that are specific to our district and Councils direction to phase in district wide water metering by 2018 to secure water supplies for current and future generations.
Rural irrigation and water supply schemes are essential to the performance and long term operation of New Zealand’s agricultural sector. This paper explains the expected impacts of climate change on rural water schemes, and identifies possible response options to better manage resources and infrastructure in response to climatic changes. It draws on a comprehensive study completed for the Ministry of Agriculture and Forestry to assess climate change impacts on rural water infrastructure, and identify opportunities to implement changes to how rural water schemes are managed to minimise the future impacts of climate change.
This paper outlines Western Bay of Plenty District Council’s approach in upgrading defunct and ad hoc creek and shoreline protection measures along the Waihi Beach coastline. It also includes community consultation undertaken during design / consenting and construction phases of the project and the “trials and tribulations” in dealing with interested / concerned stakeholders.
The Nelson Regional Sewerage Business Unit’s (NRSBU’s) decision to proceed with a 2.6km, 800mm diameter HDPE pipeline crossing the Waimea Inlet to their Bell Island wastewater treatment plant faced significant consenting hurdles due to the sensitive estuarine environment and cultural concerns for the estuary crossing. This paper describes the consultative approach taken to accommodate these issues and concerns, to achieve a pragmatic and cost effective consent outcome. Technical aspects of the project are also described.
This paper describes two contrasting long duration pumping tests with an unusually comprehensive monitoring regime. The approach was designed to help assess the potential effects of constructing the tunnel in “open mode”. Although the pumping bores are close together, the response to pumping was very different with the first test located in an area of significantly higher permeability.
Sewage spills into the Whangarei harbour during wet weather cause a public health risk to those using the harbour for contact recreation and shellfish collection. Solving the cause of the spills, inflow and infiltration of stormwater into the sewer network, is made difficult for a number of reasons including: the inability of the community to fund large capital projects, Whangarei’s high rainfall rate, the private and public sewer network is aging, and the soil type exacerbates inflow and infiltration.
Customers worldwide expect from their water utility to be supplied with drinking water in sufficient quantity, quality and continuity. In many cases, leakage from water supply systems represents a major obstruction to achieve this aim. But in the light of scarce and further diminishing water resources, extensive water losses are incompatible with the principles of sustainable management.
This paper outlines the result of this exercise and in doing so gives a clear picture of where I/I management practices and outcomes being achieved here in New Zealand are at in relation to those in the researched countries. It also discusses the Best Practice Guideline Document and its applicability for use New Zealand water industry going forward.
The Hamilton Water Treatment Plant upgrade cost $23 million and was constructed over a 20 month period in 2006 and 2007. The existing plant was a conventional plant with coagulation, sedimentation, and sand filtration followed by disinfection. It had a capacity of 85ML/d.
In addressing the impacts on water resources of persistent drought conditions and population increases, there has been considerable capital expenditure for Melbourne, Australia, into new water supply sources and related infrastructure. This investment includes a new desalination plant.
On 17 May 2005 Solid Energy committed to a five-year programme to improve the water quality of the Ngakawau River. Following extensive stakeholder consultation, Solid Energy committed to agreed waterquality targets of pH ? 4.7 (99% of the time); Al < 1 mg/L (99% of the time); NTU to be no greater than 25 NTU (based on a 30-day rolling median); and clarity to be >54 cm (NIWA Clarity Tube) > 90% of the time during base flow conditions (base flow is typically observed 70 to 75% of the time).
This paper will discuss the challenges and solutions employed in order to successfully deploy, retrieve, and analyze data for an untethered device in pipelines for several utilities.
This paper will examine key LRV parameters and present evidence comparing empirical data with theoretical calculations and relate the differences to the recommendations of the Membrane Filtration Guidance Manual. An overview of the different options available for parameters such as flow rate, transmembrane pressure, flow regime, and temperature will be provided. The timing of the integrity test and its relationship with the plant operation will also be reviewed since its impact can be significant on the outcome of the test. Lastly, due to its significant influence on the LRV calculations, a comparison between the theoretical model and experimental data will be presented on the Volumetric Concentration Factor.
The advent of national water qualifications triggered significant changes to the distribution of skilled people who are responsible for the operation of water supply and wastewater networks and treatment plants. Most water industry employers have recognised the need to employ qualified people. The aging population, the lack of popular awareness of career opportunities and changing technologies are just some of the reasons that have been put forward in response to employers who have experienced difficulties with employing the right people.
Within a single generation, the sophistication of wastewater treatment plants (WwTP’s) in New Zealand has taken a giant step forward. Historically, wastewater from the majority of New Zealanders was treated by low technology processes such as oxidation ponds or trickling filters. Activated sludge (AS) based treatment processes, which are more complex, are now by far the most common type of treatment process by population served.
This paper gives the HDC perspective on why we put the challenges in our path and how we overcame them. The Downer perspective of being engaged through the process and the HDC/Downer perspective of what the first year has brought, ups and downs, and what we expect the next four years to look like.
There is an increasing demand for water especially from agribusiness, electricity generators and urban growth. In 2010, the majority of consumptive weekly allocations were for irrigation (46 percent) and hydro generation (41 percent) with the remainder shared among public drinking supply, industry and stock watering. An increasing number of catchments are either over-allocated or nearing full allocation. By 2012 it is predicted that freshwater resources in our most economically significant regions will be fully allocated to users. The effects of climate change are only going to exacerbate this situation particularly in eastern parts of New Zealand where droughts are predicted to increase. The demand for water is outstripping supply. All these factors are going to make it increasingly difficult for councils and municipal suppliers to protect existing supplies for municipal water and secure additional supplies to provide for the long term growth of towns and cities.