Wimmera Catchment Management Authority catchment monitoring officer Mark Toomey said the Wimmera River flow, which began last month from a combination of water passing Huddleston Weir, environmental flows and good rainfall, had improved the health of the river.

The authority released a map of the Wimmera River in mid-October showing the effect the flows had already had on salinity levels.

It showed electrical conductivity readings, a measurement for salinity, near Jeparit in January were 100,000 microsiemen, in July the reading was 61,000 and then 9000 when the river began to flow.

On Wednesday Mr Toomey said the levels had dropped again to 3000 microsiemen.

``The reading in January can be explained by summer weather and evaporation,'' he said. ``In July there was some local run-off and salinity had declined but was still above the reading for sea water. Now after the river has been flowing for several weeks the reading is just 3000 which is a great improvement.''

He said similar results had been seen along the length of the river, including at Horseshoe Bend near Dimboola.

He said the reading for Horseshoe Bend was 13,000 microsiemen before the flow. It was now 1100.

Mr Toomey said lower salinity and increased water levels created a better environment for native wildlife.

``There has been a noticeable increase in the number of birds in the area, not just along the Wimmera River but also in west Wimmera wetlands,'' he said. ``A lot of frogs are fairly drought tolerant and have survived and now the conditions are better they will be taking the opportunity to disperse and breed. The flow also gives an opportunity for indigenous fish species to breed, although they don't just depend on flow, but also temperature and the time of year.''

Mr Toomey said the improvement in the river had been great to see but it would take several years of flows to improve it dramatically.