Author: Petra Stock
A surface water and/or groundwater study (also called hydrology and hydrogeology) may be required as part of a development application for a proposed wind farm, or required as one of the planning permit conditions.
This type of study is undertaken to demonstrate that potential impacts on surface water and groundwater can be appropriately managed. Water issues rarely influence the wind farm layout or pose a serious threat to planning approval.
More about water
Surface water relates to water above the ground surface in streams, rivers, drainage channels, lakes, and wetlands. Groundwater is water which is stored underground in aquifers (fractures or pores in rocks or soil). Surface water and groundwater assessments investigate potential water quality impacts resulting from construction. The assessment may also identify sources of water for use during construction, for example at the concrete batching plant, construction compound or for dust suppression.
Scoping the job for a consultant
When engaging a consultant to write a water and/or groundwater report it is best to follow the tips and tricks in the article Engaging specialists for environmental & technical studies. Essentially that article suggests writing a tight scope and getting multiple quotes for the job.
The scope should generally include:
- A detailed description of your wind farm including turbine types or dimensions and their locations. If this is still unknown, it's best to include a 'wind farm envelope' — the largest area in which turbines could be sited
- The reason you are having the report written (e.g. to satisfy planning conditions)
- Who will need to read the report
- What you expect too see in the report (See 'what to expect' below).
Information a consultant will need
The inputs to a water report are usually:
- a standard project description, including type and number of turbines, location of the site
- GPS coordinates of the site boundary, and the locations of wind turbines, access tracks, electrical cabling, substations and other infrastructure.
What to expect in the consultant report
A good consultant report will be a stand-alone document with plenty of description such that it can be interpreted by somebody who is not a professional in the field.
A standard water assessment for a proposed wind farm would usually include:
- a review of local, state and federal planning policies and guidelines relevant to water issues.
- consultation with the local and State water and catchment management authorities.
- a description of surface water catchments in the vicinity of the site, the underlying groundwater tables, local drainage networks, and rainfall.
- surface water characteristics, existing quality, and uses.
- groundwater characteristics, depths, confined or unconfined, quality, uses.
- a description of activities during construction and operation that have the potential to impact on water quality such as fuel spills, earthworks, sedimentation, and waterway crossings.
- a list of proposed mitigation and management measures.
Implications for wind farm layout
Surface water and groundwater considerations rarely affect the wind farm layout as wind turbines are usually located in elevated locations away from drainage lines or areas subject to inundation, in addition, potential impacts can be avoided or minimised by the implementation of an environmental management plan during construction.
Management and mitigation measures
A water and groundwater study usually makes a set of recommendations for minimising impacts on water quality and supply during construction and operation. These recommendations usually become a chapter of a broader environmental management plan for the site.
Measures usually include:
- any relevant codes, environmental protection policies or guidelines applicable that must be followed.
- any required permits for waterway crossings or works in waterways.
- design of access tracks and waterway crossings to avoid erosion and sedimentation.
- requirement for a bunded area to be used during construction for storage of fuels and other potential contaminants.
- revegetation after earthworks.
- scheduling works for the drier parts of the year.
- dust management.