DesignFlow

Waterway Assessment and Protection
Windaroo Creek Waterways Assessment
Client: Stockand and Logan City Council
The Bahrs Scrub Land Development Area (LDA) has been subject to significant modification through historical land clearance, agriculture, horticulture and construction of infrastructure including numerous road crossings. Consequently, the hydrological characteristics of many of the waterways within the LDA have been substantially modified, often resulting in poor water quality, loss of aquatic and riparian habitat, and stream instability issues.
 
An assessment of the upper reaches of the Windaroo Creek Catchment was undertaken to determine the condition of waterways within the Bahrs Scrub LDA. The waterway assessment focused upon:
In-stream aquatic habitat components assessed included: water quality, aquatic and riparian vegetation, woody debris, fluvial processes, presence of weeds, siltation and continuity of aquatic habitat between stream reaches.
 
The Riparian Quality assessment included: vegetation community structure (presence of life-forms, i.e. canopy trees, understorey trees and shrubs, herbs, graminoids, climbers, ferns and byrophytes), degradation caused by stock access and the continuity of the riparian vegetation along the waterways.
 
The data collected during the field assessment was used to classify and GIS map the condition of waterways in the upper Windaroo Creek catchment; and to determine the minimum riparian buffers required and whether the Queensland waterway stability objectives apply to future development within the Bahrs Scrub LDA.
 
 
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Bundamba Creek Rapid Waterways Assessment
Client: Urban Land Development Authority and Ipswich City Council
Bundamba Creek lies within the large Ripley Valley urban land release area south of Ipswich. The soils in the region are highly dispersive meaning all the waterways, including Bundamba Creek, are prone to serious erosion as a result of hydrologic change. The Urban Land Development Authoritiy (ULDA) commissioned DesignFlow in collaboration with Hydrobiology to complete a rapid assessment of 3km reach of Bundamba Creek and floodplain which is to be developed into a regional parkland and sporting facility. There is concern the erosive nature of the creek poses a significant risk to the long term function of the parkland.
 
The assessment completed found the waterway in relatively stable condition with a healthy in-stream ecology. Management of riparian weeds is required and there are a number of locations where the stream bank needs to be stabilised to minise the risk of waterway erosion. Strategic advice was provided by DesignFlow to Council and the ULDA regarding the preservation and management of the waterway as well as the placement of parkland infrastructure within the floodplain.
 
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Wantima Creek
Client: Moreton Bay Regional Council
Wantima Creek is a small urban waterway that has been identified by Moreton Bay Regional Council as a high priority for stormwater management works as a result of drainage and water quality concerns. DesignFlow developed a stormwater and waterway management design for the creek in collaboration with Alluvium. A rapid waterway assessment was undertaken to define the condition of the in-stream ecology, stability of the waterway (poor in some locations) and identify drainage and flood concerns.
 
The findings of the assessment were used to define design objectives for the waterway and then to establish a series of stormwater and waterway management options. A final strategy for the management of the creek was established in close consultation with Council and involves updating a large flood storage system, retrofitting a number of GPTs and constructed wetland systems, updating drainage in the lower portions of the catchment and stabilising small sections of the waterway. This design was broadly costed allowing Council to make funding applications for the high priority works in the catchment which includes updating an existing flood storage system and delivering a new stormwater treatment wetland. This infrastructure is due to be delivered soon.
 
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Plantation Palms: Wetland Classification and Mapping
Client: Xcel Properties
A flora survey was undertaken to describe the wetland vegetation communities present at the Plantation Palms site.
 
Accurate mapping of the existing wetland vegetation was required to delineate the existing freshwater wetland systems and to ensure that constructed stormwater treatment wetlands and associated infrastructure were strategically located to minimise any adverse impacts upon the existing wetlands and to minimise the removal of native vegetation at the site.
 
The vegetation communities associated with the permanent and ephemeral freshwater wetland systems were surveyed, and all vascular plant species present recorded. The locations of significant plant species and/or vegetation communities within the wetland areas were mapped using GPS.
 
Advice regarding the management of significant wetland vegetation communities, weed control, wetland buffer zones and monitoring was also provided.  
 
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Moreton Bay: Identification of Regional Stormwater Treatment Wetland Locations
Client: Moreton Bay Regional Council
The Moreton Bay Region has experienced a period of rapid growth and urbanisation in the past 10-15 years. The impact of urbanisation on the health of local streams and rivers and marine receiving environments generally is well documented. As urbanisation in the Moreton Bay Region is expected to continue to increase, urgent strategic planning preparation is required to identify opportunities to mitigate potential impacts of stormwater on waterway health. To this end, Council has previously developed the Total Water Cycle Management Strategy (TWCMS) for Moreton Bay Regional Council which identified stormwater quality as a major issue in all urbanised catchments in the region. As part of the TWCMS planning Council commissioned DesignFlow to assist with identifying regional stormwater treatment wetland opportunities across the LGA. This involved a GIS site selection process to identify locations where constructed wetlands can feasibly be delivered, site inspections to verify the site conditions for a constructed wetland, development of conceptual designs and establishment of a simple framework for presenting the design, cost and investigation requirements for each site. The work was completed collaboratively between Council and DesignFlow allowing both groups to build capacity ad skills. 
 
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Wonnangatta River: Riparian Condition Assessment
Client: Alluvium - West Gipplsland Catchment Management Authority
A rapid assessment of riparian condition along the Wonnangatta River was undertaken as part of a larger program monitoring the baseline condition of the high flow channel. The monitoring program aims to evaluate the effectiveness of stream recovery works (including erosion stabilisation, stock exclusion and revegetation) in the upper Wonnangatta River valley that is being implemented by the East Gippsland CMA following a severe flooding event in 2007.
 
Rapid assessment of riparian condition was undertaken using the Habitat Hectares assessment tool. This involved the determination of riparian ecological vegetation communities (EVCs) and the use of EVC benchmarks to assess riparian condition. The Habitat Hectares rapid assessments involved measuring a suite of riparian habitat components such as: large trees, tree canopy cover, understorey, weeds, recruitment of native species, organic litter, logs and landscape context (i.e. patch size and the amount and configuration of native vegetation within proximity of the habitat zone).
 
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