All aquaculture facilities require a supply of water. It is important to have a reliable, good-quality water source and equipment to transfer water to and within the facility. The volume of water needed depends on the facility size, the species and the production system. In some cases can it be very large, up to several hundred m3/min (Fig. 2.1). This is equivalent to the water supply to a quite large villages, considering that in Norway a normal value for the water supply per person is up 180 litres per day.
If something fails with the water supply or distribution system it may result in disaster for the aquaculture facilities. This also emphasizes the importance of good knowledge in this area. Correct design and construction of the water inlet system is an absolute requirement to avoid large unnecessary problems in the future. For instance, this may be apparent when the inlet system is too small and the water flow rate to the facility is lower than expected.
The science of the movement of water is called hydrodynamics, and in this chapter the important factors of this field are described with emphasis upon aquaculture. In addition, a description of the actual materials and parts for water transport are given: pipes, pipe parts (fittings) and pumps. Much more specific literature is available in all these fields (basic fluid mechanics,1–3 pipes and pipe parts,4–6 pumps7–9).