Hatchery Quality Assurance Program - NSW Department of Primary ...

RESERVOIR
ESSENTIAL CRITERIA
• Screened inlet for surface waters:
500 µm screen to prevent the entry of trash fish
(all life cycle stages, including larvae) and other
aquatic organisms into the reservoir; robust
screen, e.g. 2m x 2m stainless steel (see Fig. 6.2).
• Screened outlet for all waters:
5 mm to prevent the escape of trash fish from
the reservoir.
• Capacity to drain and dry reservoir:
for the following reasons:
(i) to remove all fish, especially trash fish;
(ii) to desiccate pathogens;
(iii) to enable disinfection, e.g. application
of lime to the substrate;
(iv) to enable silt to be removed and/or the
substrate to be tilled or scraped;
(v) to enable repairs and general maintenance.
Fig. 6.2 Diagram of the water supply inlet at the Grafton
Aquaculture Centre showing the horizontal screen used to
exclude aquatic organisms.
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NSW Department of Primary Industries | Design and operation of facilities
6.2 - RESERVOIR
The reservoir receives and stores water from
the major source. It enables control of supply
and quality, exclusion of trash fish and other
unwanted aquatic organisms, and efficient
delivery of water to ponds and the hatchery.
The reservoir provides a reserve of water at
critical times, e.g. during power failure, pump
break-down and flood. Reservoirs are normally
earthen, with separate and screened inlets and
outlets (Fig. 6.3). Water from under-ground
supplies can be stored in earthen, fibreglass,
plastic or concrete reservoirs. Reservoirs should
be aerated to prevent stratification and to
maintain good water quality.
RESERVOIR
RECOMMENDED CRITERIA
• Located and constructed to enable gravity flow:
efficient, reliable and economical delivery of water to
all facilities.
• Capacity should exceed twice volume of largest
ponds:
e.g. if largest pond holds 5 ML, reservoir should be
at least 10 ML.
• Aeration:
e.g. paddlewheel or diffused aerator, to maintain
good water quality and prevent or reduce
stratification.
• Back-up water supply for hatchery building:
an elevated reservoir to ensure water is available
under gravity during power failure.
Fig. 6.3 Reservoir at Grafton Aquaculture Centre showing inlet,
aerator and outlet tower.