How healthy is your local catchment ?

The annual Healthy Waterways Report Card communicates the health of South East Queensland’s waterways.

 

Western Catchments

Bremer River

The Bremer River catchment, with a total area of 2,031km², is the third largest catchment in the Western catchments reporting zone. The riparian areas along the reach of this creek are largely degraded and there is widespread erosion along the river and its tributaries. The Bundamba Sewage Treatment Plant discharges into the Bremer River Estuary.

Before the railway line from Ipswich to Brisbane was completed in 1875, the river served as an important navigation route between the two towns. The river has historically had poor water quality with industrial waste flowing into the river soon after the catchment was settled. The slow-flowing river system is known to flood and during the January 2011 floods reached up to 19.25m. During normal conditions however, the Bremer does not receive enough water in its catchment to meet both anthropogenic requirements and retain the ability to flush out impurities. This has resulted in poor water quality with high levels of turbidity, nutrients and bacteria.

The deadly bacteria E. coli became such an issue after the 2011 floods that the Ipswich council was forced to close all recreational use of the river. Water treatment plants damaged in January’s flooding disaster caused the bacterial outbreak and while all were swiftly repaired, E. coli levels remained unsafe for several months. Prior to this however, defence officials from the RAAF Base at Amberley admitted their site had contaminated a creek which runs into the Bremer River, with cancer-causing chemicals. In 2009, tests done by the Environmental Protection Agency discovered the creek was high in cadmium, nickel, mercury and chromium; polluting the waterway to an unsafe level. The Ipswich council has recognised the need to improve the Bremer’s water quality and initiatives such as the Bremer River Forum and the Ipswich River Heart Parklands (IRHP) are working to involve stakeholders and community groups in developing solutions to restore the rivers health.

Healthy Waterways has monitored 7 sites along the river monthly since 2000.

Brisbane River

The Brisbane River is the longest river in South East Queensland, flowing through the city of Brisbane before discharging into Moreton Bay. Early travellers along the river noted its natural beauty, abundance of fish and rich riparian vegetation. Dredging of the river from 1862 for navigation purposes sparked the end of Brisbane River’s clear water days. The constant extraction of river bed material had considerable effect on the river, with impacts including increased turbidity, bank and bed erosion and changed tidal hydraulics.

The Brisbane River catchment is the most developed in the Moreton region. Agriculture predominates in the upper reaches, high density urban regions are found in the middle reaches and industrial and port developments dominate the lower reaches and the river mouth. Historically the Brisbane River has received large amounts of treated sewage effluent including effluent from two of the largest sewage treatment plants in the region. In total however, the lower reaches of the Brisbane River which are monitored by Healthy Waterways include a total of eight waste water treatment plants. Over the last decade there has been significant investment in upgrading Luggage Point and Oxley as well as other sewage treatment plants along the Brisbane River, aimed largely at reducing nutrient loading to the system and Moreton Bay.

Environmentally, the river is in a poor condition and has been so for many years. The major causes of pollution are excess nutrients, hydrocarbons, pesticides and bacteria which become concentrated in the river and its sediment after flowing off surrounding lands.

Healthy Waterways has monitored 16 sites within the Brisbane River on a monthly basis since 2000.

Lockyer

The Lockyer catchment covers 2974 square kilometres across the steep ranges of the Great Dividing Range falling to undulating low hills surrounding lower Lockyer Creek. The Lockyer Valley comprises almost one quarter of the entire Brisbane River catchment. Rich in biodiversity, the Lockyer catchment is home to a range of native and threatened plant and animal species. It is also one of the world’s most fertile and productive agricultural areas.

Numerous dams impound the catchment including Atkinsons Dam, Lake Clarendon and Lake Dyer. Historically, plentiful water resources in the catchment have been used to irrigate extensive cropping from groundwater aquifers. However demand has exceeded sustainable yiel, especially during periods of drought, resulting in poor quality water with high concentrations of salt making it less suitable for irrigation. Highly erosive soils in surrounding hillsides and erosion of agricultural soil has also impacted on water resources, including drying up of waterholes and silting up of creeks.

Healthy Waterways has monitored 14 sites on a monthly basis since 2000.

Stanley

The Stanley River catchment covers 1535 square kilometres with the Stanley River flowing south from the Blackall Range across the wide valley floor into Somerset Dam and eventually Wivenhoe Dam. The dominant land uses in the catchment area include the water supply dams, cattle grazing, crops and dairy farms, turf and horticulture. Almost one quarter of the catchment is National Park or Forest Reserve.

An increasingly unstable climate leading to rising temperatures and more intensive storms presents a potential threat to agricultural and conservation land in the catchment. Sediment and nutrient loss from overgrazed areas, gully and streambank erosion all have significant impacts on the Stanley River and downstream water quality entering Somerset and Wivenhoe Dams.

Healthy Waterways has monitored 8 sites on a monthly basis since 2000.