BREC Report
BREC Concept Plan
BREC Recommendations
Apendices
Appendix 1 B4C Report
B4C Recommendations
Appendix 2 Federal Significance Report

CONSERVATION VALUES

The area is recognised by the Brisbane City Council as being of high nature conservation value in successive studies including the Bulimba Ck Flood Study, the Bulimba Ck Catchment plan and the Brisbane City plan.

The Bulimba Creek catchment was seen to be a high priority area for the Federal Government bushcare, wetlands and endangered species programs. The State government has acknowledged the critical role of wetlands and fish habitat areas in Fisheries, Natural Resource Management and Conservation Policies.

The SEQ Natural Resource Strategy identifies Bulimba Ck and Moreton Bay as ongoing priority areas for measures to aid water quality, water flow and flooding and fisheries habitat protection.

The recent SEQ Water Quality Strategy demonstrated that 60% of pollutants came from non point sources. The strategy highlighted the importance of riparian and flood plain management in maintaining the water quality and ecological health of the Moreton Bay Marine Park. Recent outbreaks of toxic algae in the bay have confirmed the impacts of inappropriate land use on the bay.

The Doboy Wetlands area lies at the edge of the tidal and freshwater areas of the Brisbane River Mouth. The area contains habitat for a range of fish, crabs, birds, reptiles, amphibians and other animals. A report from the CRES "ANUCLIM 1.8" database, on this area, revealed the likelihood of 11 Migratory Species, 17 Threatened Species and 28 marine protected species.

The area lies below the R100 floodline and large parts of the site are covered by high tide at least twice a year. In 1 in 5 year floods the important channel is the main one with only minor inundation occurring across the site. In bigger flood events the water breaks the banks and fills the saltmarsh areas and the overflow. The tidal flows push upstream and would have flooded all the saltmarsh areas at least twice a year and the mangroves twice daily. The hydro-ecological processes in these areas are combination of water volume, flushing frequency, residence time and biological activity. Historically the volumes would have been high and the residence time would have been some days after the flood peak. One of the major hydro-ecological functions of floodplains is energy and volume dissipation. This helps remove sediments and woody debris from floods and the deposition of these materials provides the base nourishment to support the estuarine flood plain ecosystem. The dispersal of water over the flood plain provides the timely flushing of salts from these areas build up and eventual salt panning as well as minimising the impacts of downstream channel erosion.

CURRENT ISSUES

Historical filling including the upgrade to the rail line has altered the water flows across the floodplain.

The previous effluent disposal while contributing water to the freshwater wetlands also contributed significant quantities of nitrogen to the area.

The filling and restriction of channel flow to a narrow area has created poor flushing of both tidal and freshwater areas. In the case of the brackish wetlands, dieback due to hyper- salinity is evident. There are reports of increased flooding upstream of the railway line.

The damming of the floodplain has increased residency time and volumes upstream of the railway line. It has decreased freshwater volumes and residency times downstream. The dam has blocked tidal flows travelling to upstream areas except by way of the main channel. In the tidal areas this poor flushing has lead to a build up of nutrients and algal growth. The saltmarsh and samphire shows reduced vigour. Examination of air photos from 1994 and recent photography show a strong decline in the wetland areas. This dieback is explicable due to changes in the balance between freshwater and tidal flows.

There is a strong risk of acid sulphate soils in the area. Lime treatment while stabilising the pH can also mobilise metals such as aluminium in a bioavailable and water soluble form.(colloidal aluminium)

Furthermore recent modelling of climate change impacts by DNR has shown that we should anticipate a 0.2m rise in sea level by 2050 and 0.5m rise by 2100.

The resultant storm surges, salinity and groundwater fluctuations pose a risk to any infrastructure.

The Concept Plan for Ecological Protection

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The concept plan attached outlines some methods of restoring flow to the area. In designing the concept plan we arranged the flow so that the energy dissipation function of the floodplain is protected and the measures wont increase erosion. We have 26m of flow width entering the railway embankment and 29 m of flow width leaving the Port Rd embankment downstream. Each of the culverts have forebays to settle sediment and break up flow paths.

The Oxbow area has a number of problems due to historical pollution and contemporary flushing problems. To correct this and allow natural regeneration to occur we recommend the removal of the blockage caused by the access road. We also recommend that at least a 10m width of flow be allowed to enter the Oxbow from Bulimba Creek to the south. An addition of a flow point at the Eastern end of the wetland will also help the flow in this area.

The main channel of Bulimba Ck has become restricted by the railway bridge as indicated on the airphoto by the mangrove line. We recommend the continuation of the built structure of the road from the sewer line all the way to the other side. We also recommend that the rail bridge be widened by installing additional culverts to allow tidal and freshwater flows.

 

RECOMMENDATIONS

• Ensure 50-100 m buffer , including riparian vegetation, to the creek line as required by Vegetation Management Act and Water Act.

Restore flow and flushing to wetlands, mangroves and saltmarshes by

• Widening flow points on railway and planned Port Road on Bulimba Creek to mangrove line on Western bank and to 100m on the Eastern bank
• Remove fill from between railway and road down to original level
• Improve flow under railway and planned Port Road in middle section with culverts of various size as indicated the Concept Plan.
• Removing construction road that dams the small Oxbow channel
• Improve water flow under rail line to small Oxbow

• Prepare design modifications to planned Lytton Rd upgrade to improve water flows and protect riparian corridors.

• Prepare and implement ecological rehabilitation plan in conjunction with all stakeholders including fauna and flora recovery, road runoff control measures and water quality monitoring.

Michael Petter Coordinator

Greg Spilsbury Field Officer

Brisbane Region Environment Council

Monday, 4 December 2000

 

Appendix attached.

Report By the Bulimba Creek Catchment Coordinating Committee

http://bulimbacreek.org.au

This report is specifically covering Port of Brisbane Motorway Contracts Stage 1/Package 1 — Preload and Work drains (early works).

The area of our concern is between the Oxbow Loop at Murarrie almost to the Hemmant-Tingalpa Road on the eastern end. This area is a Habitat Node (Bulimba Creek Catchment Management Plan, Map 10 — Nature Conservation). This is also a designated wetland in the New City Plan (Wetlands and Waterways Map). It has extensive mangrove areas and is a diverse saline and freshwater complex consisting of mangrove and saltmarsh fringe. It represents a sample of vegetation once widespread in the area and now largely cleared. This floodplain land is partially inundated in flood events.

The area of concern is a typical river-mouth floodplain characterised by broad flat low-lying areas. Due to its low-lying nature, much of the area is poorly drained. The Brisbane River is the dominant water feature of the area, which supplies tidal influence to a series of smaller creeks and drains. The second largest regionally significant waterway in the area is Bulimba Creek. The meandering nature of Bulimba Creek in its lower parts causes the surrounding land at Hemmant and Murarrie to flood in heavy rain events. Doboy Swamp is another significant non-tidal wetland in this area. The main conservation values in the area are associated with the Bulimba Creek Corridor connecting to the mangrove communities along the foreshore of Moreton Bay. These surrounding wildlife habitats act as extensions to natural areas within the Gateway Ports area, enhancing opportunities for species biodiversity and fauna movement between core habitat areas, especially for ground birds and animals.

The preload system of construction rather than pylon bridge method will alter the flood events in the habitats concerned. At this time the biology of the habitat concerned is not sufficiently well understood to make the judgment that alteration of the flood regime would have little or no effect. It would be better from the view-point of future generations to apply the precautionary principal. The movement and scope of flood waters would not be so restricted by pylon construction and bridging as by preload system.

Current flood studies and their recommendations of previous and outdated modeling.

The 25% upstream catchment development (1974) is now likely to be over 50% and the latest information on updating projections could be as high as 89%.

Qrail Act only requires Qrail to build bridges to present upstream development. Thus their drainage beneath the Brisbane to Cleveland line is not capable of handling the many fully developed catchments. Thus some time in the future several rail culverts and bridges may need to be dug up and replaced with enlarged ones to reduce flooding upstream.

The Maunsell Study of the Port Road reported that the culverts beneath the rail line between Hemmant and Lindum Stations are undersized. These were built during the Dual Gauge Rail Line Installation. The Dual Gage Rail Line study was also carried our by Maunsell. QRail built the culverts to Maunsell’s design.

Preloading the Port Road is seen as a cumulative impact along with the railway line.

• Sensitive Mangrove, Casuarina and Eucalyptus dominated vegetation communities interspersed with permanent and ephemeral wetlands;
• The area has major ecological significance within the east/west habitat corridor linking the intertidal areas of Moreton Bay with the Brisbane River;
• Low-lying areas and swampland are overland flood flow for Bulimba Creek;
• Mangroves near Doboy Bridge have high conservation value for fish, crustacean, waterbirds and waders and also supporting one of the largest colonies of flying foxes in the Brisbane area.
• A diverse saline and freshwater wetland complex consisting of a mangrove and saltmarsh fringe in good condition;
• Well developed Eucalyptus woodland remnant on nearby low hill in good condition, with rainforest alliances;
• The area represents a sample of a type of vegetation once widespread in the area but now largely cleared;
• Contains corridor and buffer value between residential and industrial areas.

The area is designated as "Habitat Node" in the Bulimba Creek Catchment Management Plan (Map 10 Nature Conservation). It has diversity in habitats ranging from mangroves and salt marsh to remnant Casuarina and Eucalypt woodland to wetland areas.

No commissioned species lists have been accessed by our group at this time. Wildnet has not responded nor Mr Ian Venebles (who may have wader studies of the area). From our recent limited survey and waterwatch visits, we can mention the following observations.

Crustaceans and small fish (saltwater species) are present in the mangrove areas. There is evidence of larger fish (silver bream and catfish from the gutting and cleaning of fish).

No threatened species have been observed in our limited study. We have seen healthy and impacted communities of invertebrates and bottom of the food chain species.

Evidence of Brown Bandicoot from diggings, evidence of Brush Tailed possum and Squirrel Gliders from scratches on eucalypts. Confirmed sighting of Ringtailed Possum.

The area is well known for a diverse number of raptor species. Kites, osprey and goshawks were observed on our survey. There have been red rumped parrots seen here in late 1988.

Lathome’s Snipe were observed early September 2000. Grass Owls, Brown Quail, Cattle Egrets, Glossy Ibis, White-faced Herons, 4 species of cormorant, Chestnut Teal, Black Duck, Wood Duck and Giant Egret.

Birds — common:

We observed several commonly seen native species for urban areas (eg magpies, minors, dollar birds, kingfishers, kookaburras, doves etc. Also exotic species (eg Indian minor).

Diverse ground and potential arboreal nest sites were found.

A professionally sponsored fauna survey would add significantly to this limited and hastily-prepared survey. The absence of such a survey means the presence of Threatened Species has not yet been determined.

The area has existing access and natural processes that assist the movement of ground and arboreal fauna. The connectivity of areas of mangroves and saltmarsh will be impacted by preloading. The wetlands and woodland remnants need to be left with corridor linkages.

The rail line has not got the full impact that a preloaded main road will have, because of easier fauna and genetic transfer by the absence of the bollards and side of road infrastructure.

Impeding the corridor connection will impact on the diversity and food species and their productivity. This will in turn affect the habitat requirement of higher species downstream.

The Bulimba Creek Corridor would be effectively cut at its most critical point.

This will compromise all the good work upstream in bushcare, biodiversity protection and water quality works.

This acts as an important wildlife corridor between remnant bushland and wetland areas within and beyond the area concerned and provides linkages to other bushland areas containing large areas of open space and riparian vegetation connecting through to the area to be traversed.

Freshwater is supplied from Bulimba Creek to several freshwater wetlands such as Doboy Swamp and the Oxbow Loop at Murarrie which in turn form important habitats for many species of fauna in highly disturbed area of the Gateway and Port vicinity.

The area concerned contains saltmarsh and brackish habitats which provide a sanctuary to a large number of species including migratory waders from the northern hemisphere. This type of eco-system is also important to the larval stages of many types of fish and crustaceans.

The creek area to the north of the rail line has extensive mangrove areas that are an important fish and marine species hatchery. Fishing adjacent to this area has been an recreational opportunity for many years. Along with the conservation areas downstream (designated in the Draft City Plan 1999) the area has important ecological services to Moreton Bay and its marine ecosystems.

The area is of educational value due to proximity and accessibility from schools and universities within the Brisbane region.

The area of the Bulimba Creek corridor has been recognized by the Brisbane City Council and our catchment plan as an area of diverse recreational opportunities for the future.

The options are:

• Bikeways
• Walking Tracks
• Boardwalks
• Fishing
• Canoe Trail (pontoon points, launching facilities, viewing decks)
• Recreational boating — Boat launching facilities
• Nature observance and education
• Bushcare projects
• Wader studies and birdwatching hides

1. That the area marked on Bulimba Creek corridor for preloading and early works (Package 1) be transferred to Package 3 — proposed bridge structure sections.
2. The community consultation should be facilitated through the local member for Bulimba Mr Pat Purcell and transparency of the process be paramount.
3. Studies should be undertaken on the impacts of the State Rail Line and the proposed Lytton Road upgrade. With an aim to remediating interruption to natural processes.
4. Consultants Reports: A code of ethics needs to be legislated, which obliges consultants for consultants to give ethical and objective reports. If the reports are ethical this should not impact on the consultants’ future commerciality.

Report prepared by: Wayne Cameron

on behalf of the Bulimba Creek Catchment Coordinating Committee Inc.

• New South Wales National Parks and Wildlife Service
• Department of Natural Resources and Environment, Victoria (Secretary)
• Department of Primary Industries, Water and Environment, Tasmania
• Department of Environment and Heritage, South Australia Planning SA
• Parks and Wildlife Commission of the Northern Territory
• Queensland Environment Protection Agency
• Birds Australia
• Australian Bird and Bat Banding Scheme
• Australian National Wildlife Collection
• Natural history museums of Australia
• Queensland Herbarium
• Royal Botanic Gardens and National Herbarium of NSW
• Royal Botanic Gardens and National Herbarium of Victoria
• Tasmanian Herbarium
• State Herbarium of South Australia
• Northern Territory Herbarium
• Western Australian Herbarium
• Australian National Herbarium, Atherton and Canberra
• University of New England
• Other groups and individuals

For further information see http://www.environment.gov.au/epbc

© Commonwealth of Australia