CONCERNS have been raised about the environmental impact of a scheme to take more water from the River Test. The Test and Itchen Association fears the breeding patterns of the Test’s Atlantic salmon population could be disrupted by a reduction in the river level. The association's worries have been sparked by Southern Water’s plan to abstract more water from the Test and less from the Itchen. From 2015, the amount the firm can take from the River Itchen between June and September will be capped, with a complete ban on abstraction during exceptionally dry summers because it has been designated a Special Area of Conservation. Southern Water has announced a proposal to link Testwood Water Supply Works in Totton to its sister site in Otterbourne by an 11.5-mile underground pipeline and upgrade the Testwood works, to compensate for the Itchen reductions. This would allow water chiefs to abstract up to 136 million litres of water a day from the Test, which it already has a licence to do, some of which would be transported to Otterbourne. Southern Water has said it will only take its full quota during periods of severe drought. However, the Test and Itchen Association, which represents land owners on the river and fisheries, wants this assurance backed by law. It wants an independent regulator to decide what classifies a drought and is calling on Southern Water to relinquish its original licence, which it says was granted before the effects of water abstraction were really understood. It is estimated around 1,000 salmon make the journey up the River Test to lay their eggs every year. Tom Davis, director of the Test and Itchen Association, said salmon levels in the Test were already “precarious”. The association said that abstracting large amounts of water would lower the river and reduce flow. It says that the salmon rely on scent to find their way from the ocean back up the river to spawn and reducing the flow weakens that signal. Lowered river levels raise the water’s temperature and reduce its oxygen content, making the fish’s journey harder, it claims. Salmon not moving up river because of low flow could be more liable to predators and poaching. The fish return to their original spawning grounds and cannot breed elsewhere, so a unique strain of salmon only found in certain chalk streams in the south could be threatened, said the association. “We’re very keen on the protection of the River Itchen, but not at the expense of other rivers,” said Mr Davis. Southern Water said it had worked closely with Natural England and the Environment Agency to gauge the effects of their proposals and discussions were continuing. A spokeswoman said: “The conclusion of the study was that abstracting water at the full licence rate is unlikely to have an adverse effect on the general health of the river including the fish, plants and invertebrates that live within it and in particular on the movement of fish along the river.” She did not rule out the possibility of the licence being changed.