The planning stage of any finfish aquaculture facility development (new or expanding), is crucial not only for financial success, but also as an opportunity to design the development in a way which will not cause undue influences on the environment.
New finfish aquaculture facilities and any expansion of existing aquaculture facilities, must be designed and planned to minimise the risk of harm to the environment. Where reasonable and practicable, the planning and design of proposed finfishfarms must incorporate the following:
- Identification of features of the aquaculture facility and its environment which are important aspects of ecological value;
- Vegetated buffer zones and where necessary habitat corridors;
- Water intake points must be located to create access to suitable quality water, while recognising the need to minimise disturbance and potential impacts to aquatic and riparian vegetation;
- Pond wall batters must be constructed from suitable material and designed with optimal batter angles to prevent slump and erosion;
- Consideration of prevailing wind direction in order to reduce wave setup and associated bank erosion;
- Farm layouts must minimise disturbance to acid sulphate soils;
- Water recirculation systems for freshwater facilities as a first option;
- Use of discharge water for irrigation in freshwater facilities as a second option;
- Pond/tank drainage may be through a monk gate, siphon or stand pipe and must be completely drainable;
- Pond/tank drainage structures must be designed to prevent escape of cultured animals;
- Ponds/tanks must be designed to maintain appropriate freeboard levels;
- Ponds/tanks must be fitted with appropriately designed overflow/spillway mechanisms to maintain freeboards and prevent escape;
- Design must minimise overland flows entering ponds;
- Discharge points must be located to create access to waterways that will maximise the dispersion of discharge waters and minimise impacts to hydraulics, while recognising the need to minimise disturbance and potential impacts to aquatic ecosystems;
- Aquaculture facility size must be limited according to the capacity of the receiving environment to disperse and assimilate waste waters (if any), toensure that unacceptable pressure is not placed on these systems;
- Where non-endemic or exotic species are to be produced, facilities must be constructed above the 1 in 100 year flood level;
- Areas of significant vegetation must be preserved, wherever and whenever possible, provided that the economic and productive efficiencies of the operation are not compromised.
The final design must ensure that the proposed facility will operate in an environmentally sustainable manner and in accordance with other sections of this Code of Practice.
Construction:
Correct construction of the aquaculture facility is likely to lead to increased profitability through savings in maintenance and unexpected construction failures. Finfish aquaculture facilities must be constructed in such a way as to minimise the risk of harm to surrounding areas.
Where reasonable and practicable, the following practices must be complied with when constructing a new finfish aquaculture facility.
Earthworks and Erosion Control:
- The area disturbed must be limited to the immediate construction area;
- Appropriate methods (such as perimeter bunds), must be used to prevent overland flow from entering the construction site;
- Appropriate methods must be used to reduce erosion of topsoil from within the development site and subsequent siltation of waterways (such as using hay bales or sediment traps);
- Stripped top soil must be stored within a bunded area;
- Appropriate management plans should be implemented to prevent siltation of downstream locations;
- Downstream conditions must be checked for possible erosion and/or flooding due to concentrated flows and appropriate management plans undertaken where necessary;
- Top soil must be placed over pond walls and suitable vegetation must be encouraged to grow on the pond walls and batters, or other erosion protection methods must be used.
- Encourage and manage vegetation to control erosion.
Acid Sulphate Soils:
- If disturbed, acid sulphate soils must be managed by burial, neutralisation or other forms of treatment;
- Leakage of acid leachate must be prevented, minimised or treated;
- Areas where acid sulphate soils have been disturbed and exposed must be rehabilitated.
Groundwater:
- Ponds must be constructed from material capable of retaining water and in a manner which will minimise seepage.
Vegetation Clearing:
- Clearing and disposal of cleared vegetation shall be in accordance with the Administering Authority requirements.
Noise & Dust:
Construction activities must be undertaken such that the impact of noise and dust on the environment will be minimised.
Information Prepared By:
Dallas J Donovan
Information Sourced From:
