Document Type

Thesis

Publication details

Tulau, M 2011, 'Lands of the richest character: agricultural drainage of backswamp wetlands on the North Coast of New South Wales, Australia : development, conservation and policy change : an environmental history', PhD thesis, Southern Cross University, Lismore, NSW.

Copyright M Tulau 2011

Abstract

The floodplains on the North Coast of New South Wales once included extensive open freshwater backswamps. These areas have elevations close to, or even below, mean sea level. The poor drainage resulted in vast open reedlands, sedgelands and open grassy woodlands on the Tweed, Richmond, Clarence, Macleay, Manning and other floodplains. From the earliest days of European settlement, individual settlers attempted to drain these backswamps, but with limited success – the swamps remained largely undrained, and were generally only used for opportunistic rough grazing in dry seasons. In order to implement closer settlement policy after1862, a greater coordination of effort and intervention by the State was required, establishing a pattern of increasing government involvement over the following ~100 years.

A type of specific purpose 'local government’ was introduced to the floodplains in the latter part of the 1800s in the form of drainage unions. However, due to the voluntary nature of drainage unions, their limited financial capacity, and certain legal concerns, few unions were formed, and those that did produced for the most part only modest results.

The next major phase in the evolution of floodplain policy, which took effect in the early 1900s, reflected the increasing capacity of the State, and followed developments in water supply and irrigation in inland areas. There, the State constructed the water works, and formed water trusts to manage them and rate the benefited landholders. On the coast, drainage works were constructed under the authority of the Public Works Department (PWD), and drainage trusts formed. Major works were constructed in most large backswamps on the North Coast, particularly during the period from 1906 to 1914. This was an important but now largely forgotten period in the transformation of coastal floodplain swamps, because many trusts failed financially – it was found that 'the land could not repay’ the investment in infrastructure. There were also some spectacular failures – some canals allowed saline water to flow back into the backswamps. Much of the land was simply too low.

A long dry period ended in the late 1940s, and flooding returned, but this time to floodplains that had been extensively alienated, subdivided and settled. There was considerable damage and loss of life, notably at Kempsey (1949) and Maitland (1955). Along with other factors, these events created a favourable political climate for the construction of major ‘flood mitigation’ works. The schemes were advocated locally by agricultural interests and designed and constructed by or on behalf of local government, with funding and administration provided by the PWD.

The schemes were made possible by solving the problem that had defeated swamp drainage proposed in the past, by ‘casting the net of contribution’ out to its maximum extent to include all three levels of government. The crucial step was the entry of the Federal Government into the funding formula in

1964, a major policy shift that was achieved, in the face of longstanding opposition, due to an unlikely confluence of events. The Menzies Government had been returned in 1961, but with a majority of only one in the lower house. It had lost the North Coast seat of Cowper largely on the issue of flood mitigation, and shortly thereafter another large flood hit the North Coast.

Although triggered by disasters in floodplain towns, most ‘flood mitigation’ scheme works were constructed for the purposes of swamp drainage. Over $43M has been spent on coastal floodplain drainage and flood mitigation schemes, mostly on the Tweed, Richmond, Clarence and Macleay River floodplains. It was during the period from 1964 to 1976 that flood mitigation finally ‘came of age’. It was the major turning point in the transformation of the coastal floodplain freshwater backswamps. Although many had previously been extensively drained, a more widespread use of headworks and floodgates to drain to local low tide level removed the last vestiges of swamp in most areas.

Ironically, the flood of 1963 was to be the last major flood in the post-war flood-dominated period. A dry spell set in, which exacerbated the impacts from the drainage schemes. Additionally, the late period of construction overlapped with the rise of environmental concerns, and the realisation that the drainage works were often accompanied by a number of adverse impacts. Early concerns were raised by wildlife supporters, but fisheries interests, with stronger statutory and proprietary rights would prove more influential in the longer term. The impacts of certain works on the Macleay floodplain were particularly controversial, such as the closure of Yarrahapinni Broadwater, an event that was to prove an influential factor in the development of fisheries and environmental policy generally.

A major environmental policy shift occurred following changes of government at Federal, and later, State, levels. In relation to floodplain wetlands, the highest priority was to prevent their further degradation, and this was partly achieved by a series of planning and other responses. The regulation of development on acid sulfate soils illustrates the limitations of this approach, with wetlands policy and regulation being more successful.

However, the principal challenge remains the remediation of already degraded wetlands. Here, and despite the environmental issues that have arisen in recent decades, many State department and local government policy objectives have remained remarkably stable over time. Issues are accommodated within the longstanding objectives of each group, including agricultural production and fisheries management. Indeed, devolution of policy-setting and environmental management to stakeholders has been presented as the solution to sustainable floodplain management. Historically, fisheries policy has been influential. More recently, the sugar industry in particular has achieved a leadership role in floodplain management.

The limitations of existing approaches are now being acknowledged. A major issue is whether wetland rehabilitation, water quality and other floodplain objectives can be achieved within the context of agricultural land uses in backswamps. If not, the options for sustainable land use are limited. Governments are increasingly employing a range of devices to achieve control over the use of floodplains and returning land to public control, and often, ownership. However, the rehabilitation of freshwater backswamp wetlands remains a largely unresolved issue.

Share

COinS