Natural Heritage Trust, Primary Industries and Resource SA and the Department for Environment, Heritage and Aboriginal Affairs. 1999. Upper South East Dryland Salinity and Flood Management Plan - Progress Report October 1999.

The Upper South East Dryland Salinity and Flood Management Plan was developed in response to community concerns over increasing areas of salinised land and flooding in the Upper South East. The Management Plan outlines an intergrated approach to combat rising watertables, while taking into account environmental, economic and social concerns in the region. Stage 1 of the drainage works, the Fariview Drain, was completed in May 1998 and is currently undergoing a drainage trial to assess the impact on water levels. The drain has a dual role in that it provides groundwater control to land adjacent to the drain and also allows control of surface water flows for the 27,500 ha of land within the drains catchment.

Additionally, the Bakers Range Watercourse has been upgraded to cope with extra volumes of water from the Fairview Drain and divert good quality water to the Watervalley Wetalnds. A floodway has been incorporated into the design to separate groundwater and surface water and provide a ribbon of enhanced wetlands. Construction of the upgrade was completed in August 1998. The Kercoonda Drain allows excess good quality water to be diverted to Coorong via the Tilley Swamp watercourse as well as divert saline water away from wetlands in summer. This drain was completed in April 1999.
Mr Tom Brinkworth has constructed drains that form an integral part of managing wetlands on his property. Approximately 35km of these drains are located within the vicinity of where regional drains were proposed by the USEDS&FMP and were therefore are acquired from Mr Brinkworth for inclusion in the co-ordinated regional drainage network

Large areas of land have been degraded by salinisation in the Upper South East region as a result of the combined effects of high groundwater levels and flooding. The extent of salinisation in the rgion has been increasing over time.
As well as land productivity there are also significant environmental issues in the area, with the presence of high value wetlands, including the Coorong at the downstream end, and areas of significant remnant vegetation.

The Fairview Drain was officially opened on the 7th October 1998 and is the first stage of drainage works of the Upper South East Dryland Salinity and Flood Management Plan. The open channel earthen drain is nominally 2 metres deep and stretches 54 km from its commencement east of Fairview Conservation Park to its discharge into the Blackford Drain. Construction of the drain involved excavation of approximately 780,000 m3 of material. Spoil banks are managed to avoid negative impacts such as weed growth and erosion.
The drain has a bed width of 2 metres in the upstream section which increases to 5.5 metres in the downstream section. The elevation of the bed of the drain in 34.1 m AHD at the upstream end and declines to 16.2 m AHD at the junction with the Blackford Drain. At times when the drain is carrying water suitable for use in wetlands, drain flow will be diverted north via the Bakers Range Diversion into the Bakers Range Watercourse.

Preliminary observations from the Fairview drainage trial are that groundwater levels have been lowered in areas adjacent to the drains. The zone of groundwater level lowering extended 1 to 1.5 km west of the drain and 1.5 to 2.5km east of the drain, during the trial. At this point ther are insufficient data to evalaute the impacts of increased groundwater inflows to the drain on discharge salinity.
The drainage component of the plan is expected to cost $24 million over 6 years and is jointly being funded by State Government (37.5%), Commonwealth Government (37.5%) and the local community (25%). To collect the community contribution, a complex levy arrangement was adopted, with differential rates according to different zones in the catchment. The model has widespread community acceptance and 98% of the community contribution to the project to date, has been paid.

Total expenditure in the drainage component to the end of June 1999 is $8,045,000. The majority of this has been used for drain construction (132km) and represents $60,000/km of drain.

The introduction of deep surface drains in suitable dryland areas can have a significant impact on water tables, the productivity in surrounding properties and the health of environmental systems such as wetlands. However this study has raised a wide range of social and environmental issues which need to be considered for a large scale drainage scheme. Careful management, detailed investigations and a high quality monitoring system are required before regional scale drains can be implemented.

The following are key determining factors for the successful implementation of deep drains to control shallow water levels and elevated soil salinities in dryland areas:

• drain spacing adequate to maintain the water table at a particular depth below the ground surface;
• a ?perceptive value? derived from the visual decline of waterlogging and saline scalds;
• a level of economic return from the land subject to the drains;
• a level of economic value of the re-used water;
• ability to re-use the drained water;
• a suitable drainage disposal or storage strategy; and
• a perceived or actual benefit from the protection of areas other than dryland.