If it wasnt for a few pesky mosquitoes and occasional tidal inundation problems it may well have stayed that way.

Instead, war was declared on what local media in late 1960s described as a landmark that Newcastle could well do without which needed to be cut down to size.

The Ironbark Creek floodgates, installed in the early 1970s, functioned as a virtual tourniquet on the swamp for almost four decades.

The former estuarine habitat became a freshwater swamp dominated by pastures, reeds and weeds.

The marine fauna and migratory shorebirds that were once abundant declined dramatically.

The launch of the Hexham Swamp Rehabilitation Project, one of Australias most ambitious environmental restoration blueprints, in November 1996 marked the start of the long road back to environmental health.

A key component of the plan was reintroduction of tidal flow through the staged reopening of the Hexham floodgates between 2008 and 2013.

In total, 443 hectares of estuarine vegetation and habitat has been restored.

The number of juvenile eastern king prawns and school prawns have substantially increased, Callaghan Cotter from Hunter Local Land Services said.

Over 40 new bird species have been recorded, including migrating shorebirds from Siberia and Asia, some of which are protected under international agreements, Mr Cotter said.

Located 12 kilometres northwest of Newcastle the wetland is a popular location for birdwatchers.

The area also provides a vital habitat for wildlife and a valuable nutrient sink and nursery ground for fish and other marine and bird life.

It is a coastal drought refuge area for many waterfowl species, and hosts several migratory species of wading birds during summer.

About $7million has been spent on the project, which includes land acquisition, bund construction and ecological surveys.

A further $3 million has been spent on approvals, management and monitoring.

Two decades of professional and volunteer efforts to bring the wetland back to life will be celebrated on Friday with a tour of the rehabilitated wetlands.

The results are fantastic and reflect all of the hard work that has gone into this project over the past 20 years.

We owe a great debt to the many community stakeholders and volunteers who have been involved over the years, either through the committee or campaigning for the project to go ahead, Mr Cotter said..