Brisbane Region Environment Council
Preliminary Rehabilitation Recommendations
Brandon St Wetlands Runcorn
To initially replant the wetland areas with Melaleuca species to suppress the water table. To rehabilitate riparian areas with closed canopy vegetation. After 10-15 years the eucalypts and other species could be re-introduced into the area to complete the restoration of this ecosystem.
In the short term the priority will be planning, monitoring, preliminary replanting and weed control.
DEH could require an EMP of BCC, developers and landholders to protect the environmental value of the waterway and wetland.
Waterway and Wetland areas
Internal cluster planting with Melaleuca spp and other saline tolerant wetland trees and understorey species.
Wetland edge planting with small shrubs, reeds, rushes and sedges.
Weed control and removal is a priority particularly groundsel, grasses and Stramonium spp.
Other riparian areas
All areas up to 1.5 m above surface water level should be replanted at maximum density to lower the water table.
Immediate riparian areas are recommended for rehabilitation or revegetation to achieve a near closed canopy.
No further filling in this area be permitted.
Strict enforcement of erosion and sediment control in this sub-catchment.
Excessive sediment build up in all waterways should be immediately assessed.
Notification to be provided to all developers in the immediate catchment of these changed circumstances.
Infiltration and runoff balance
In its near natural state this wetland would have had high infiltration upstream and this water would have been part of its original water balance. Development has reduced infiltration rates and increased the amount of surface water entering the wetland.
Given that wetlands are natural ponds that act as water collection points with reduced stream flow and water purification qualities, an increase in surface water can only be released at the discharge rate and this creates extended periods of ponding.
The removal of the riparian trees has also increased the ponding by raising the water table and compounded by the rate of increased sediment which is infilling the wetlands.
The future water balance for the wetland should look to lower the water table, and decreasing the volumes and timing of surface runoff.
Old Water Level = runoff+infiltration+groundwater-(evaporation+transpiration+discharge)
Current Water Level = 2*runoff+groundwater-(evaporation+discharge)
Community campaign to reduce watering and runoff. (B4C, Waterwise)
Community campaign on rehabilitation and conservation agreements (B4C, Land for Wildlife)