There is a new push on in National Party circles to put the construction of billion dollar Welcome Reef Dam on the Upper Reaches of the Shoalhaven River, back on the agenda.

The proposal was discussed among delegates at the state National Party conference held in Bowral over the weekend, and will also be included in an Upper House "  Development " inquiry.

There have been suggestions for dams and power stations on the river near O'Allen Ford going back 101 years, with the most recent proposal deferred indefinitely  in 2000.

While long opposed by conservationists, some National Party members believe Welcome Reef is the only way to drought proof Sydney in the next big dry.

Water in the storage  would  be released into the Shoalhaven River and then gravity flow to Tallowa Dam at Kangaroo Valley, from where it would be pumped to Sydney and Wollongong.

Terry Barratt from the Shoalhaven River Alliance says the concept of Welcome Reef is fundamentally flawed, and will not solve any water shortage problems