Cape Jaffa Development
For more than three years, Tonkin Consulting has undertaken a number of major projects associated with the development of infrastructure at Cape Jaffa. Having an approximate construction cost of over $70M, this project comprises a 550+ lot residential and commercial marina, including the associated service infrastructure.
Tonkin Consulting has provided the full range of engineering and environmental design and development services associated with the project including the preparation of an Environmental Impact Statement (EIS).
In addition, specialist sub consultants were engaged to assist in the coastal investigation, sand movement, sea level rise, tidal flushing, groundwater modelling and marine ecology surveys.
Social impacts, including the affects on the local community and region, were assessed and details regarding the impacts to the local environment were presented within the EIS.
A climatology study of the region was prepared by the Tonkin Consulting project team, to better understand the local weather and the impacts this would have in developing the concept layout, including the breakwater configuration.
As the development is remote, many background studies were required to development a background of data to assist in assessing the local impacts. These included the installation of 30 groundwater wells, and a tide gauge to measure tidal events.
Monitoring and collation of the data was then undertaken and used as inputs into many of the models that were developed for the project.
Modelling of the water quality was undertaken to determine the impacts of freshwater and potential nutrient contamination due to the residential development. Computer-generated currents and dilution vectors were produced to provide confidence that the marina would attain suitable flushing of the canal areas without adversely impacting on the marine environment.
Tonkin Consulting assisted in the preparation of all necessary documentation to obtain statutory approvals for various components including negotiation of sea bed lease, concrete batching plant approval, mining leases, wastewater treatment facility and town water supply allocation from the confined and unconfined aquifers.
Aboriginal Heritage and Native Vegetation studies were prepared to assist in obtaining all necessary clearances, to enable to project construction to occur.
Referrals to all government agencies were undertaken including the preparation of Environmental Protection and Biodiversity Conservation (EPBC) Act submission for the project.
Groundwater Investigation
As part of the EIS process, groundwater monitoring was required to research the impacts on the local groundwater within the site and to better understand the aquifer systems in the region.
Our team undertook a detailed hydro-geological investigation on-site, an extensive review of regional background data and modelling of the freshwater / seawater interface location relative to the marina and its immediate surrounds. Groundwater discharge to the marina was estimated using a MODFLOW model developed by a sub-consultant to Tonkin Consulting.
Within the South-East region there exists two main aquifer systems – an upper unconfined aquifer and a deeper confined aquifer. The groundwater flow directions and levels were monitored to determine what impact the waterway canal construction and operation would have on the local groundwater. In addition the water quality of the local groundwater was assessed and modelling undertaken on the mixing between sea and fresh water and the impacts that this may have on the marine environment and users of the local groundwater system.
Tonkin Consulting is involved with ongoing monitoring of the groundwater within the site as part of the facility management.
Potable Water Supply Hydrogeological Investigation
Tonkin Consulting staff undertook hydro-geological investigations to prove an alternative to the more remote source identified during the approvals process. This necessitated long term pump tests to monitor drawdown and establish aquifer conditions at the alternative bore field.
Our team liaised with DWLBC regarding water allocation for the development and undertook investigations of recharge, impact on shallow bores and groundwater dependent ecosystem to verify the aquifer(s) sustainability.
An extensive desktop study was undertaken to determine the most likely location to construct the production bore(s). Water sampling was undertaken to verify water quality. Tonkin Consulting carried out detailed hydrogeological investigation of the interconnectivity between the unconfined and confined aquifer within the local region.
We also completed geophysical logging, pumping test and analysis to determine aquifer properties, and sustainability assessment as part of the application for water allocation under the new Water Allocation Plan. As part of the approval, ongoing groundwater monitoring is to be undertaken to ensure that the groundwater dependant ecosystem at close by Hog Lake is not adversely impacted.
Marine Study
The Cape Jaffa Marina, marine survey investigation was a collaborative effort between SARDI and Tonkin Consulting to assist in better understanding the marine environment of the region. With the assistance of SARDI, we undertook a marine survey of the area to prepare a habitat map of the area, as well as jointly assessing the overall potential impacts of the development.
In order to assess the potential implications of the Cape Jaffa Anchorage development on the marine environment, it was necessary to prepare a habitat map of the area. While some information was currently available on marine habitats around Cape Jaffa, video surveys were conducted to provide further details of the sessile marine macro fauna and flora present.
Using this information Tonkin Consulting was able to develop a number of monitoring and management plans to ensure any impacts on the marine environment were minimised during the during construction and operation of the facility. These plans included dredging, marine construction, marina operation, water quality testing, sea grass and groundwater monitoring.
For more information phone Jeff Tyler on 8273 3100. |
