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Ecosystem Functions

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Water Regulation

The influence of land cover, topography, soils, hydrological conditions in the spatial and temporal distribution of water through atmosphere, soils, aquifers, rivers, lakes and wetlands.



Regulating Functions

How does water regulation contribute to ecosystem service provision?

Waterfalls, such as Moran Falls, result from a sharp change in the topography.

Natural ecosystems play a crucial role in the hydrological cycle through affecting transpiration and evaporation and influencing how water is channeled and stored in a catchment. The water regulation function underlies the health of SEQ ecosystems by distributing water required for sustaining all ecosystems and species. The table below (Table 1) presents the relative magnitude water regulation contributes to different ecosystem services (relative to other ecosystem functions) in SEQ.

The water regulation function underlies the livability of SEQ, primarily by distributing water across the region for human consumptive purposes (e.g. for irrigation, stock watering, production, drinking and other human uses). The channeling of water into streams and rivers provides an important part of the transport infrastructure in SEQ. For example, how would the City Cats on the Brisbane River travel without adequate water to keep them afloat?

The successful growing of food crops (both in terms of growth rates and cost effectiveness) is highly dependent on this ecosystem function as it limits human inputs such as water transportation for irrigation. Features of the natural ecosystem such as riparian zones (stream bank vegetation) play an important role in maintaining water quality through natural filtration effects and bank stability. Forests and wetland ecosystems within catchments help regulate flows through attenuating floods and maintaining flows during dry periods.

The productive soils of SEQ on floodplains such as the Lockyer Valley have been partially built through sediment deposition in flood events. Aquatic ecosystems are vital to the survival of iconic species such as the lungfish. Rivers, streams and wetlands in SEQ have been accorded significant cultural values for SEQ'ers who enjoy the opportunities they provide such as recreation, inspiration cultural diversity and therapeutic landscapes. Spiritual values are held by many Traditional Owners towards the spatial and temporal distribution of water. Aquatic ecosystems are an iconic feature of SEQ (e.g. the Bremer, Logan and Albert, and Brisbane Rivers).



What is the temporal and geographic scale water regulation operates at and services are delivered?

Temporal scale??

The water regulation function is one directional (downslope). The water regulation function is produced in a specific location (such as a mountain top forest). The fluid nature of water thus means the potential benefits to people are downslope over time in the form of regulated and extended water provision. 


The map to the right shows areas where the function water regulation is expected to occur across SEQ. Data sets supporting the map can be found in the Quick Index. By clicking on the link below the map it will provide a more detailed view.


How do we know if we are degrading, maintaining or improving water regulation in SEQ?


Rivers regulate water through channels whilst instream vegetation and rocks regulate the flow rates.

Links to other publications and websites

Floodplains are vital to regulating the spatial and temporal distribution of water across SEQ. Directional changes to natural drainage and changes to surface permeability can strongly impact on this function in both beneficial and non-beneficial ways. These changes can be identified by land cover and land use maps, or physically they can results in a decrease or increase in the quantity and/or rate of water flow (e.g. flooding). Water regulation is also important to replenishing aquifers, however groundwater regulation is more difficult to monitor than surface water regulation.

In the time since European settlement the degradation of this ecosystem function has been significant. Poor water quality in rivers and streams and increased sedimentation rates in Moreton Bay are the most apparent manifestations of this decline. This poor water quality can be attributed in part to the loss of flushing of waterways. The Healthy Waterways Report Card and associated grades for aquatic ecosystems are key indicators of this ecosystem function.


How do we manage this ecosystem function in SEQ?

Although the importance of the water regulating function is widely recognised, management of this function can be characterised as treating symptoms rather than causes. Declining water quality has been managed through the building of  water treatment plants. Losses to the water regulating function have been addressed through dam construction. Surface cover (e.g. vegetation, rocks), slope, drainage lines and surface permeability are important factors influencing the spatial and temporal distribution of water. Appropriate land use planning is key to protecting flood plains, decreasing sedimentation of waterways and maintaining vegetation that can improve this ecosystem function. A recognition of the economic value of this ecosystem service is emerging, though the long timeframes involved in ecosystem restoration do not match well with shorter term needs. The Queensland Government's Department of Energy and Water Supply is responsible for managing water regulation through dams. The Department of State Development Infrastructure and Planning is responsible for the SEQ Regional Plan 2009 - 2031 and Local Government's for sub-regional Planning Schemes.