The SCIRT alliance is responsible for the rebuild of Christchurch’s horizontal infrastructure following the 2010 and 2011 earthquakes. Its stormwater objective is “to return the Land Drainage network to a condition that will facilitate the provision of levels of service that were provided prior to the 4 September 2010 earthquake.”
This paper details the collaborative design approach undertaken for the HBCSS pressure sewerage system, including constructability and operability reviews. It also discusses including the innovative use of dynamic modeling to develop the design.
This paper outlines the technical challenges and solutions the team developed to meet those challenges and how Watercare Services Limited has met the needs of the communities of Kumeu, Huapai and Riverhead.
This paper discusses the challenges the project team faced in implementing the project and identifies how these were met. This includes the setting up a joint community communication and engagement plan, a project governance group and consideration of contractual models at the onset of the project. The project was a great success as it was completed on time and in budget, and achieved a 99 percent property connection rate.
This paper will introduce the CMPTP methodology and provide case studies of installations completed in Hastings, Whakatane, Auckland, Wainuiomata, Masterton and Christchurch City.
Edgecumbe township is located between major river, canal and stop bank flood protection systems. The town is subject to severe stormwater flooding in relatively minor events. The 28 January 2011 rainfall event was considered to be significantly smaller than the 10-year stormwater design standard, however a number of properties were flooded.
Timaru District Council (TDC) was issued with a new ocean outfall resource consent in February 2011. It has subsequently separated Timaru City’s domestic and industrial wastes and is constructing a new treatment plant for domestic wastewater (WWTP).
A number of New Zealand councils have introduced universal water metering over the last 30 years; others have partial metering and some no metering at all. Different councils are currently considering the implementation of universal metering as part of their Long Term Plan. This paper reviews some of the current approaches to water metering in New Zealand and overseas. This is based on a literature review and discussions with individual councils.
In New Zealand many of the rural based councils have historically attracted industry into the region, especially large food processing plants, so that local employment is maintained. Many of these plants enjoyed low trade waste costs for many years as a result of this implicit social benefit relationship.
Pump Station 15 (PS15), commissioned in 1970, conveys wastewater from Woolston to the Christchurch Wastewater Treatment Plant for approximately 40,000 population equivalents. The 2011 Christchurch earthquakes resulted in significant damage to and prolonged wastewater overflow from PS15. The damage observed included reverse graded gravity pipes, shear failure of pressure pipe and service connections at structures and separation of the station superstructure due to different foundation conditions.
The Canterbury earthquakes damaged the wastewater pipes in Christchurch, reducing the security and resilience of the remaining network. An alliance between Canterbury Earthquake Recovery Authority, Christchurch City Council and New Zealand Transport Agency, and five non-owner participants created the Stronger Christchurch Infrastructure Rebuild Team (SCIRT). Working with many other companies they are all combining together for the vision of creating resilient infrastructure for Christchurch.
This paper will look at the technology selection process, the options considered and will build upon last year’s paper “King Tides – A Royal Problem” by Nicola Brown, Harrison Grierson(2012). It will examine how the existing plant and originally proposed upgrade was unsuitable for the raw water conditions. It will also provide an in-depth and detailed assessment of two different technologies and explain how a saving of over $3 million dollars was achieved on the initial estimates.
This paper will discuss the outcomes of three case studies and the factors to consider before practical application of these rainwater tank systems.
The paper traverses the journey from inception to completion and highlights some of the challenges and smart solutions implemented to provide redundancy and treatment security and defer capital investment by maximising the use and performance of existing assets at the two operational wastewater treatment plants.
Continued regional growth and the need to secure the Auckland region’s water supply against drought prompted a fast-tracked project to expand the capacity of one of Watercare’s most strategic assets, the Waikato Water Treatment Plant (WTP), from 75 Megalitres per day (MLD) to 125 MLD. The expansion project planning/design phase commenced in November 2010 with the upgraded 125 MLD treatment capacity being fully realised, on time and budget, in March 2013. An interim stage was included to remove plant bottlenecks and increase the interim plant capacity to 100 MLD, this was achieved, on target, in December 2011 enhancing drought risk mitigation for the 2011/2012 summer and beyond.
We will describe the challenges of trialing a new innovation in a dynamic environment where sludge is being removed biologically but also being introduced daily by the flows and loads entering the WWTP. It is demanding to calculate rates of removal in a dynamic environment where the sludge is being hydrated and rising vertically while being carried horizontally by winds and currents.
Acid corrosion of concrete pipes is a well documented degradation mechanism for this product which is used as a vital component of New Zealand’s infrastructure. This paper will review and update the various acid attack mechanisms that are common to the industry and outline design solutions accordingly. All acid attack mechanisms are not equal and are often confused in this regard with the provision of sulfate resistance. The paper will clarify these issues.
Polyethylene pipe included in Christchurch water and gas reticulation systems performed extremely well in the 2010/11 Canterbury earthquakes. Based on this performance, polyethylene pipe has been used more extensively for repair and reconstruction works. This has required careful consideration of aspects of the design and construction to ensure that the high level of performance is replicated for the wider range of applications.
Cascade drop manholes are used (where permitted by the local authority) to avoid crossing services; in an attempt to expend energy within the drainage network; or to reduce pipe grades. Hydraulics through drop manholes is not widely documented, and research such as documented in Granata, de Marinis et al, (2011) indicates that drop manholes can have a significant, unexpected, deleterious effect on the hydraulic capacity of the system.
This paper looks at the assessment processes and repair techniques utilised to stabilise the wastewater network and maintain service to the residents of Christchurch. At May 2013 Council had spent a total of $155 million on earthquake wastewater repairs and maintenance. $65 million has been utilised solely on repairs and stabilisation of the wastewater network.