R O A D VA L E S A L I N I T Y S T R AT E G Y

Why manage salinityAll water, including rain, contains salts. Salinity is a natural process caused by weathering of rocks and concentration of salts by evaporation and plant transpiration. Human activities in developing land and water resources can change the hydrological balance in sensitive areas resulting in salinity problems.

Salinity becomes an issue when the concentration of soluble salts in soil or water increase to levels that affect water quality, soil properties, plant growth, ecosystems diversity, farming productivity and built infrastructure.

Research has shown that, dryland salinity is imposing large costs on local governments, households, businesses, agricultural producers, state government agencies and utilities, the environment and cultural heritage.

Whether and how salinity becomes evident at a particular location depends on the interaction of many factors such as characteristics of the landscape itself, the climate and the effect of human activities.

What is causing the salinity at Roadvale

Investigations so far reveal that:

• Approximately 189ha of salt affected land was identified in the Roadvale area (Figure 1).

• An extensive salt affected alluvial valley exists upstream of Milbong.

BackgroundThe Roadvale project area covers approximately 4369ha and is located in the upper Purga Creek catchment. This is a hydrologically sensitive catchment with a long history of salinity. Since settlement land management activities have increased

• A geological constriction at “One Eye” waterhole restricts groundwater movement downstream.

• The number of existing artesian bores in the local area indicate the area could be a discharge zone for the Clarence Moreton Basin, part of the Great Artesian Basin. Further investigations into the source of this groundwater is required.

• Brigalow and Tea-tree vegetation in the Roadvale district confirm the majority of soils in the area are slowly permeable, heavy clay soils with naturally high salt loads.

• Despite the area being naturally susceptible to salinity, built infrastructure such as roads and sediment from erosion has made the salinity issues on the floodplain worse by not allowing the water to flow freely.

• Numerous leaking dams exist in the area, which exacerbate the salinity problems.

• The area has seen decreased cultivation and decreased rainfall, yet aerial photos from 1944 show a continuing increase in the area affected by salt since then.

• Salinity in the area will get worse if nothing is done. Active management is urgently required.

GoalsTo ensure:

1. Land resources and their productive capacity are maintained and protected from salinisation, sustainable production systems are developed and salinity management practices are put in place which prevent further land degradation.

2. The quality of key surface and groundwater resources are improved and protected.

3. The presence and condition of key natural environmental assets, (including priority flora, fauna and ecosystems) are not threatened by salinity.

4. The threat from salinity to infrastructure and cultural heritage is avoided or minimised.

5. Productive uses of natural resources already degraded by salinity are developed and off-site impacts minimised.

6. Capacity building, knowledge and awareness in salinity prevention and management is increased.

Vision for Roadvale areaTo prevent, minimise and, where possible, reduce the extent and impacts of salinity on Roadvale’s economic, social and natural resources.

Dr. Roger Shaw

Roadvale State School

R O A D VA L E S A L I N I T Y S T R AT E G Y

StrategyIn order to manage salinity in the Roadvale area, a combination of activities and strategies are needed.

Improved land management resulting in less water making its way into the water table.

• Encourage best management such as reduce deep drainage, fence off salt affected areas and reduce grazing pressure.

• Use groundwater in the alluvial areas where water quality is acceptable.

Use water more effectively and efficiently.

• Best industry practice.

• Encourage water efficiency in farming practices.

Use engineering solutions.

• Establish a trial of controlled alluvial watertable dewatering strategy.

• If trial is successful, undertake dewatering.

Make better use of land affected by salt.

• Identify salt tolerant pasture species and fodder crops.

• Encourage property management planning to identify and manage areas affected by salinity.

• Run salinity and land management workshops.

• Trial a range of different land uses/crops/pastures to see what works in the Roadvale area.

Protect and manage native vegetation.

• Encourage the retention and enhancement of native vegetation, particularly along stream lines and near natural springs and in recharge areas.

• Provide access to information about salt tolerant native trees and guidelines for their optimal placement and establishment.

Develop the community’s capacity to understand and deal with salinity.

• Establish a local group.

• Create factsheets.

• Develop a communication strategy.

• Develop partnerships with stakeholders in the Roadvale area.

• Hold field days to share ideas and outcomes from trials.

• Develop a data storage system to house all the information from investigations, learnings from workshops, trials and other project product and outcomes.

Implement planning principles and guidelines for future development of the area that will reduce the impact of salinity.

• Develop a policy addressing impacts of non sewered subdivisions.

• Develop a policy on farm dams.

• Investigate feasibility of extending the Roadvale Water scheme to additional areas to reduce the current reliance on water from dams.

• Review roads and culvert infrastructure to see if the restrictions caused to groundwater flow can be eased or reversed.

Research, monitor, review and adapt.

• Establish baseline data and reference sites for on-going assessment and evaluation.

• Investigate the source of the groundwater.

• Establish a Monitoring and Evaluation Program to measure progress and identify the future changes required.

For more information please contact

Ph: 07 5540 5111 E: mail@scenicrim.qld.gov.au www.scenicrim.qld.gov.au

Published 2013.

Photos by SEQ Catchments, Scenic Rim Regional Council and Dr.Roger Shaw

This information or data is provided by SEQ Catchments Limited on a general basis only. You should seek specific or appropriate advice in relation to this information or data before taking any action based on its content. So far as permitted by law, SEQ Catchments Limited makes no warranty in relation to this information or data. This map is not to be sold or re-made as part of a commercial product.

www.seqcatchments.com.au

Figure 1: Salinity extent in the Purga catchment