Irrigation
Shaw has the capacity to design and construct major irrigation schemes delivering up to 45ML per day of water to farmers during peak irrigating times.
Shaw has delivered a significant number of the major irrigation schemes that have been developed over recent years by the Tasmanian Government as priority infrastructure for the State. The Shaw team has the capacity to work effectively with clients and key stakeholders to ensure all project outcomes are identified and delivered to all expectations.
Recent Projects
Project Profile
Scottsdale Irrigation Project DICL Pipelines
Scottsdale
Tasks
The Scottsdale Irrigation Project is the latest Tasmanian Irrigation Project due for commissioning in 2020. VEC Civil engaged Shaw Contracting to perform the DICL (ductile iron concrete lined) component of the project due to previous experience and success from the Winnaleah Irrigation Project.
There was 16.8km of DICL pipes in varying diameters 750mm, 500mm, 450mm, 375mm, 200mm and 150mm. DICL pipe was chosen for high pressure section of the pipeline. DICL pipe was all rubber ring jointed pipe. The dig lay was through farmland, forest areas and areas containing endangered flora and fauna.
Due to the high pressure all changes in direction required significant concrete structure for bends, sockets, bulkheads, valves and encased on major streams. This required ingenuity from Shaw to pour concrete in remote areas and engaged a sub-contractor to use concrete bowls on the back of tractors to cart from the nearest access point.
Shaw hired vacuum lifters to load, unload and stockpile pipes. This significantly improved OHS risk through eliminating personnel accessing top of pipe stacks.
At the end of the project Shaw also provided VEC an experienced fit off crew to complete air/scour valves and property outlets.
Challenges
Work was conducted through the Winter period. This required scheduling of work in accessible ground and limit activities to minimize ground impact and maintain access. Some areas of swamp required a combination of cording, container bases and gravel to maintain access.
Works were re-scheduled to stay out of a wedge tailed eagle sensitive area during breeding season. We crossed creeks that contained giant freshwater crayfish with a few being found and relocated as per the environmental license requirements.
Outcome
Work was completed ahead of schedule with no adverse environmental impact.
Project Profile
Duck Irrigation Scheme Pipeline Station & Ancillary Works
Circular Head
Task
Design and construction of an irrigation scheme for use by 30 farmers in the Circular Head region of North West Tasmania. This included 60km of Poly Pipe ranging in size from 110mm to 800mm, two pump stations and two 500kL balance tanks.
The Duck Irrigation Scheme comprises two pump stations; the Edith Creek Pump Station and Smithton Pump Station. The Edith Creek Pump station is a dual purpose station situated 15km south of Smithton, it captures winter flows from the Duck River to fill the Mill Creek Dam, and releases the irrigation water back into the duck river during summer. The Smithton Pump station, located near the township, receives the irrigation water and transfers it along the two, more than 20km reticulation networks towards Forest and Mella areas.
Challenges
The pipeline crossed over more than 50 different farms and required negotiating with many farmers with many different farm practices. The project required working around cropping times and cattle movements, detailed washdown and disinfection procedures, tight environmental constraints and a vast working area - from end to end the pipeline was 40km long.
Many locations within the construction zone were through sensitive areas and required directional drilling of pipework, these included major river crossings, road crossings and crossing strategic drainage covered by the Mowbray Drainage trust. The Duck River crossing was completed using horizontal directional drilling and was a 120m path with a 10m incline through rock boring a 600mm hole. At the Edith Creek crossing a 355mm pipe was installed through rock 80m long.
Other environmental factors that were encountered included the western end of the pipeline which was constructed through a low-lying area that was suspected of being in acid sulphate soils. When exposed to oxygen acid sulphate soils can contaminate farm lands when not handled properly. For over 20km of pipeline the acid sulphate soils were managed with lime dosing and had no reported incidents of contaminations.
The Duck Irrigation Scheme was the first scheme to include the installation of fibre optic the length of the scheme. This allows instantaneous management of flows and highly accurate tracking for water management. The fibre optic was installed in continuous lengths of up to 2km.
The majority of the works were completed through the summer of 2017/2018 with over 50 employees working to avoid the poor Circular Head winter weather conditions.
Outcome
The pump stations were completed in time to collect the winter rains from Edith Creek to begin filling the Mill Creek Dam. The Duck Irrigation Scheme was completed and in use for the 2018-2019 summer. This allowed farmers to utilize their purchased water for cropping and cattle irrigation.
Project Profile
Irrigation Scheme Augmentation
Winnaleah
Task
Shaw Contracting was awarded the $8.6million dollar Winnaleah Irrigation Scheme Augmentation (WISA) in June 2011.This design and construct project more than doubled the existing irrigation scheme through sourcing additional water from the existing Frome Dam, designing, installing and connecting approx. 11km of new pipeline from the dam and joining the existing scheme north east of the township of Winnaleah.
This project also involved the upgrading of the wave wall and outlet spillway at the Frome Dam.
Challenges
The project experienced construction and environmental challenges; being completed in a remote area and subject to extreme weather changes but also offered scope for innovation and flexibility.
Originally, a 200m section of the pipeline was to be above ground as it skirted the rocky Moorina Hill; however changes to design and some careful blasting allowed this section to be buried also.
Heritage issues included running the pipeline 1.5km along the alignment of a disused rail corridor, and the protection of an historic grave site, which lay just metres from the dam wall, believed to be that of a worker who died during the dam construction in the early 1900’s.
Environmental challenges on the job ranged from land protection through to land rehabilitation and remediation, restoration and river protection whilst completing the pipeline river crossing.
Shaw Contracting provided some innovative solutions throughout the life of the life of the project, including:
- Purchasing two vacuum pipe lifters enabling workers on site the ability to off-load from shipping containers with added safety, as well as load another Shaw innovation – a specially adapted articulated dump truck for the transportation of the pipes along the alignment.
- Conversion of an articulated dump truck for final delivery of pipes to the pipe corridor rather than the traditional method of ‘walking’ excavators while slinging pipes one at a time. Modifications included hydraulically operated locking arms, allowing nine pipes at a time to be transported along narrow, rugged construction corridors and, saving time and money whilst protecting the environment. These modifications were undertaken in Shaw’s own workshops.
- Shaw designed a ‘coat-hanger’ style, steel spreader which could lift the whole pipe, allowing for the plastic sleeve to be wrapped around the pipe and then lowered directly into the shaft – all in one operation. Again constructed in Shaw’s own workshops, this significantly sped up the laying of the pipe when combined with other initiatives.
- A helicopter was used to lift 1.25 tonne concrete blocks for a new wave wall along the top of the dam. This method proved to be quick, and much safer than normal methods of using a crane, which would have needed extensive concrete foundations to be added to the dam floor.
Outcome
This project was completed in time for the new, larger dam and reservoir to be filled by the winter rains ahead of the 2012 – 2013 growing season largely due to the team work and innovations of Shaw Contracting, enabling schedules to be met despite weather interruptions.
The completion of the augmentation extended the WISA capacity to 3,700ML and also extended its range by providing 4 additional branch lines from both the new pipeline and existing network, which greatly benefits the farming communities of Branxholm and Winnaleah.
“Shaw Contracting worked well with Tasmanian Irrigation but has also worked well with the farmers as landowners. That interface is also extremely important, one that Shaw has managed well...”
Project Profile
Dial Blythe Irrigation Scheme
South Riana
Task
Design and Construction of a 4000ML storage dam, 2 pump stations and 42km of irrigation pipework from South Riana to Penguin on Tasmania’s North West Coast for Tasmanian Irrigation and 45 local farmers in the irrigation district.
Challenges
Shaw Contracting worked closely with the design team to optimise the design for both the 18m high earth filled dam wall and the 42km of distribution network immediately after award of the contract to ensure that when works commenced the field staff had all the tools necessary to undertake the works in a continual progressive system.
With over 80 different properties to traverse, stakeholder management was paramount to Shaw to ensure continual works along the pipeline with no delays or disruption.
The construction period for the contract commenced in May 2014 and was due for completion in February 2015, which forced a considerable amount of the project to be completed over the winter months, including the construction of the dam wall in an existing waterway.
Outcome
The dam wall was constructed and started catching water by September 2014 and was completed by December 2014 which enabled a large volume of water to be stored during the last quarter of 2014 enabling Shaw to undertake pipeline commissioning and delivery of water to some farmers late in the 2014-2015 irrigation season.
The final sections of distribution pipework were installed in February 2015 and the commissioning of the scheme was completed in March 2015 ready for delivery of water to farmers, as planned, late in the 2014-2015 irrigation seasons.
Shaw completed a total of 46 road and stream crossings on this project utilising directional drill technology with a single installation of 355mm pipe, 70m long under a swamp which considerably reduced the environmental impact on the project site.
The project involved 47,000 man-hours on site both LTI and MTI free which is a successful outcome from a project safety perspective.
Overall the project has been a resounding success setting a new benchmark for Tasmanian Irrigation for innovative design outcomes and environmental standards
“A number of innovations in the contract have become new benchmarks for TI... The environmental performance has been to a level that also sets a benchmark for future projects”
Project Profile
Rubicon Irrigation Scheme
Meander River
Task
This contract involved the design and construction of 12km of irrigation pipeline from the Meander River to the Rubicon River.
Pipe was designed to provide 45 mega litres per day to three watercourses and 12 farmer outlets.
Challenges
- To construct the pipe during winter months to meet irrigation season.
- To construct the intake for the pump station in the Meander River.
- Manage landowner requirements and heritage issues.
- Meet Client’s design requirements in a cost effective manner.
- Ensure material lead times did not delay project milestones.
Outcome
Pipe was constructed successfully meeting all design flows.
“Critical success factors for the project were considerate management of landowners, quality of work and on-time completion and in all areas, Shaw Contracting exceeded expectations...”
Project Profile
North Esk Irrigation Pumps and Pipelines
North Esk
Task
Design and construct contract consisting of 2 separate components: pump station and 7km pipeline to fill Rocklands Dam. The project consisted of 55km of pipeline, pump station, pressure reduction stations, scour valves, air valves and property outlets to service 65 outlets for water from the dam to landholders. The irrigation district covered the locations of Nile, Evandale, White Hills and Relbia.
Shaw Contracting partnered with a local engineering design consultancy to perform the design. Shaw negotiated 85 separate landholder access agreements for access to properties as well as completing quality inspections on all facets of the project. Shaw organised logistics for the principal supplied HDPE pipe from the NW coast location in 20m lengths.
Construction was completed primarily using Shaw Contracting resources. Up to 5 dig/lay teams were utilised with each team consisting of 2-3 excavators and ground team. Pipe welding was completed with a combination of in-house and contracted resources. Up to 5 fit off teams were utilised for property outlets, air valves and scours.
Commissioning consisted of flushing, pressure testing and performance testing. This was completed in conjunction with the designers to ensure compliance with the tight performance specification.
All works were coordinated and managed by Shaw Contracting Project Manager and Project Engineers.
Challenges
- The timeframe was always tight with short periods for design and construction. The design and construct contract required several design workshops and submissions prior to construction commencing. This combined with a detailed specification made the design process challenging to meet expectations and commence construction on schedule. Adherence to the schedule was critical.
- As part of the contract we are required to negotiate with all affected landholders for access to properties for construction activities. This required meeting, understanding expectations from the landholder, detailing access to properties, construction activities and remediation to be undertaken. This varied in complexity from single on farm meeting where an access agreement was signed on a ute bonnet, to negotiating with a corporate body run outside of Australia.
- The project was constructed from January to December. Working through a reasonably wet winter the workforce was flexed up and down to manage this along with changing work locations to suitable ground conditions.
- The volume of components required along with principal supplied components introduced complexity into the logistics chain. 65 outlets, 112 air valves and 19 scour valves required careful management to have the landholder signed off, pipeline completed, components available and fit off teams in the correct location.
Outcome
The project provided successful outcomes to the principal. The pump station and pipeline were completed into Rocklands Dam with sufficient time for a partial fill of the dam. The distribution pipeline was constructed, tested and commissioned ready for a full irrigation season for irrigators who required water in the first season.
