Ipswich City CouncilCatchments and WaterwaysBremer CatchmentThe Bremer River Catchment is approximately 2030 km² (203 000 ha) in area and encompasses a diverse range of land uses which include agriculture, mining, industry, commerce, natural areas and urban development. The City of Ipswich lies within the Bremer River Catchment. It is a historic city as well as the residential, commercial and industrial centre of the Catchment. The Bremer River Catchment contains six major waterways, being the Bremer River, Bundamba Creek, Purga Creek, Reynolds Creek, Warrill Creek and Western Creek. The Bremer River Catchment also forms part of the Brisbane River Catchment, which is the largest river system in Southern Queensland. It is rich in history and opportunity, and the natural beauty of the surrounding mountains provides a magnificent backdrop to the rolling landscape as well as a recreational retreat for city dwellers. Flinders Peak and surrounding hills, which form part of the eastern boundary, are remnants of volcanoes active during the tertiary period - approximately 25 million years ago. Erosion and SedimentErosion - The Creeping CatastropheErosion is recognised as the greatest land degradation issue facing rural Australia. However with proper understanding and application of good land management practices, it is perhaps the most preventable form of land degradation. Erosion is basically the dislodgment and movement of soil from one location to another by wind or water. There are five main types - raindrop splash, sheet erosion, rill erosion, gully erosion, streambank collapse, and tunnel erosion. More than one type of erosion can be involved in any erosion problem. Surprisingly large quantities of soil can be lost with erosion. One centimetre of soil lost from a one hectare surface area is equivalent to approximately 100 cubic metres of soil being removed - weighing about 100 ton's. Losses of 5 to 10 cm of top soil from many hectares are fairly common during intensive summer rain. In fact, an average 10 ton's per hectare per annum soil loss from cultivation land is considered ‘acceptable'. Erosion risk is increased markedly when the soil is in a bare, cultivated condition. Within the Bremer River Catchment, Deebing Creek sub-catchment (3457ha), located south of the Ipswich urban area, is somewhat different to the other twelve sub-catchments. It consists largely of solodic soils which are highly erosive. Areas of cleared land left uncovered for the construction of residential buildings is the major contributor to this problem. This sub-catchment requires particularly stringent management strategies to reduce future erosion and sedimentation of Deebing Creek. Erosion is also considered to be a serious problem in the Mid and Lower Warrill Creek sub-catchments. Irrigation of agricultural land not only exacerbates erosion but also increases the occurrence of soil salinity. Salinity occurs when mineral salts within the soil are carried to the surface with rising ground water. Salt is then carried into the waterways with soil particles and rain water run-off. SedimentSediment or soil particles can consist of gravel, sand, silt and clay. The amount of sediment entering our creeks and rivers has substantially increased as a result of the catchment being cleared for agricultural land, soil disturbance during forestry operations, urban and industrial development and bare areas such as gravel roads and stock paths. It is the sediment that runs off into our waterways that causes our rivers to become brown, dirty and unhealthy. The river becomes out of balance and cannot cope. Creeks and rivers have responded to the changes in the catchment by changing their shape. Streambank erosion is often a symptom that the waterway is responding to a range of changes, and as a result can deliver huge amounts of soil directly to the water. The main contributors to sediment in the Bremer River and its tributaries are:
In The Bremer River CatchmentA land degradation survey of the catchment by the Department of Primary Industries in 1979 concluded that land degradation from over clearing of the vegetation, and inappropriate cropping and grazing practices, have been identified as the largest problem facing land managers in the Bremer River Catchment with more than 41 % of the catchment considered degraded. The Bremer River Catchment Management Strategy identifies erosion and sedimentation as a high priority issue within the Bremer River Catchment. The community has identified widespread sheet and gully erosion on agricultural land, gully erosion on streambanks, a lack of natural vegetation on riparian zones and a lack of cover in pasture lands as a few of the priority issues for the catchment. With increasing urban development occurring within the catchment, the ongoing control and reduction of silt and nutrients accessing our waterways is an important issue. Management and Control of Erosion and SedimentSediment and erosion problems occur throughout the entire catchment with the majority of sediment coming from cleared agricultural land within rural areas. However, when considering management strategies it is important to realise that urban areas contribute more than twice as much sediment per hectare during rain periods. Instruments to assess the amount of sediment coming from urban areas and construction sites have been set up along Mihi Creek within the Brassall area. Data collected from these sediment samplers will be used to develop and implement effective management plans for the control and management of sediment loads from developing and existing urban areas. Other management and control techniques (existing and proposed) include:
Mihi Sub-CatchmentThe Mihi CreekThe Mihi Creek forms an integral part of the Bremer River catchment system, weaving its way through the suburbs of North Ipswich and Brassall before joining the Bremer River near Woodend. Its past is rich in history yet its future has become uncertain. The impacts of past actions compounded by the pressures of development and expansion have placed the creek system in a fragile situation. If you live, work or play within the Mihi Creek catchment then you will be interested in learning about Mihi's history and the plans for its future. Extracts from the booklet are enclosed to give you an insight into ‘The Mihi Story'. HistoryDrovers on their way to the sale yards, used the creek to water their herds. As this was the main stock route, the continual animal traffic meant that little vegetation was present as there was not enough time between drovings for the grass to recover. This is why part of the Mihi Creek near Brassall State School and Ipswich High School became known as "Hungry Flat". Plants and AnimalsThe first inhabitants would have seen a very different environment - rainforest beside the creek and pines would have been common, and animals and fish plentiful. Koalas, spotted quails, platypus, echidna and a large variety of macropods (kangaroos and wallabies) would have been the predominant animals. Reptiles would have included carpet pythons, whipsnakes, water dragons and skinks. The night would have been loud with the noise of frogs. Birds would have included powerful owls, whipbirds, kingfishers, ducks and egrets. The Need for ManagementCatchment management is an approach to planning and managing our local waterways and environment. It involves everyone from residents, industry, schools, government and the Ipswich City Council contributing and working together to improve our local environment - making it a better place to live, work and play. It is a cooperative effort between everyone within the catchment, taking note of everyone's needs and desires. SolutionsReplanting native vegetation will encourage the return of native animal species, as well as controlling runoff, reducing erosion and improving water quality. Weed infestations can be controlled and feral animals removed. As a community we can plant native species, remove weed species, compost garden waste, dispose of waste correctly, limit rainfall runoff, and prevent oils, fats, solvents and other pollutants from entering the stormwater drainage system. Community ActionMany people in the area have recognised the need for action and have already commenced working to improve their local area. Clearing weeds and planting of trees native to the area along Mihi Creek and in the greater catchment area has commenced. Local schools, The Heritage City Community Church and Ipswich City Council are among many who are working towards improving the catchment. Natural ResourcesNatural Resources of the Bremer River CatchmentThe Bremer River Catchment covers an area of 2030km² (203 000ha) and forms part of the Brisbane River Catchment, which is the largest river system in Southern Queensland. It is rich in history and opportunity, and the natural beauty of the surrounding mountains provides a magnificent backdrop to the rolling landscape as well as a recreational retreat for city dwellers. Flinders Peak and surrounding hills, which form part of the eastern boundary, are remnants of volcanoes active during the tertiary period - approximately 25 million years ago. Catchment Land UsesThe current land uses within the Bremer River Catchment and the condition of the natural resources has been markedly influenced by the land uses of early European settlement. Early European settlers in the district were mainly sheep and cattle graziers. Much of the fertile scrub country was cleared and used for timber production. The rich alluvial soils found in the low lying areas and valley floors supported cultivation and crop production. Forage crops were grown for cattle and the dairy industry expanded. Cotton and sugar cane were also grown in some areas. Today, more than half of the total catchment area is used for grazing, and crop production is still an important industry within the catchment. Although urban settlement only takes up approximately 2% of the total catchment area, it supports a diverse and economically important range of commercial and industrial businesses. The following pie chart depicts the proportion of total catchment area currently being used by the four major land use types. Natural Resources Within the CatchmentWaterLess than one per cent (1280ha) of the catchment is covered by water. Moogerah Dam supplies a large proportion of the catchment with water for irrigation, drinking water to local townships, such as Boonah and Kalbar, and cooling water for Swanbank Power Station. Riparian VegetationThis vegetation grows on land adjoining waterways, gullies and dips, around lakes and on river floodplains. The natural vegetation helps to stabilise banks, shade streams reducing evaporation, provide food and habitats for birds and wildlife, and most importantly, act as a buffer for catchment run-off. Freshwater Wetlands and SwampsThese areas of land are seasonally inundated by water, generally for two to six months of the year. They act as sinks for nutrients and sediments and absorb pollutants from catchment run-off. Wetlands are also important in reducing the velocity of surface run-off, helping to prevent soil erosion whilst supporting a diverse range of wildlife. SoilsAgriculture and cropping is important within the catchment. Many commercial crops, including potatoes, carrots and onions are grown throughout the region on the rich alluvial soils. MineralsThe potential for coal mining within Ipswich encouraged early development of the area. Coal seams were discovered throughout the region. The early 1900's saw the opening of many mines including those at Rosewood and Ebenezeer. Mt Marrow, north-west of Walloon, was established as a crushed rock quarry for use in road making. Aside from coal, limestone was also discovered within the Bremer River Catchment. The Mt Flinders Dolomite Mine at Peak Crossing, established in the early 1890s, is still operational today. TimberMuch of the Bremer River Catchment, prior to European settlement, was covered by tracts of sub-tropical rainforest, eucalypt forest and large areas of ‘scrub country'. The scrub consisted of valuable timbers including hoop pine, brigalow or "rosewood", crows ash, blackbean and red cedar. This bought about the timber boom of the late 1800s. Management of Natural ResourcesIt is now well recognised that the availability and use of natural resources within the region need to be carefully managed to ensure long-term sustainability and to prevent further environmental degradation. Catchment Management (direct link) is a mechanism being used to coordinate the management of land uses within the catchment and to provide a framework in which government agencies, commerce and industry groups and the community can work together to manage natural resources in a balanced and sustainable manner. Community members can play an important role in the management of natural resources by participating in Catchment Management activities and by utilising resources in a caring and sustainable manner. Activities available to community members include:
TributariesThe Bremer River CatchmentThe Bremer River Catchment is approximately 2030 km² in area and encompasses a diverse range of land uses which include agriculture, mining, industry, commerce, natural areas and urban development. The City of Ipswich lies within the Bremer River Catchment. It is a historic city as well as the residential, commercial and industrial centre of the Catchment. The Bremer River Catchment contains six major waterways, being the Bremer River, Bundamba Creek, Purga Creek, Reynolds Creek, Warrill Creek and Western Creek. The three larger waterways, also known as sub-catchments, contain a wide range of land uses. The Bremer River Catchment Management Strategy has been developed to facilitate better management of the natural resources of the catchment, and to encourage objective decision making in accordance with community values. For the purposes of the management strategy, the Bremer River catchment has been divided into 13 sub-catchments. The following is a list of the characteristics and management issues pertaining to each sub-catchment.
Last Updated 9 Nov 2009 |
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