Storm run-off from roofs, roads and other hard surfaces can carry a wide range of pollutants into water courses. It also promotes bank and channel erosion, particularly when impervious surfaces drain rapidly to creeks and rivers via concrete drains or pipes. Undesirable environmental outcomes include increased water turbidity and increased rates of channel incision and sedimentation, reduced cover by bank vegetation (including mature trees that topple prematurely after being undermined), loss of refuge pools, and reduced availability of substrates such as pebbles, cobbles, rocks and organic matter that support edible macroinvertebrates. Because a female platypus’s breeding success depends so strongly on her being able to access abundant food, the occurrence of adult females has been found to be more limited by impacts of run-off than the occurrence of either adult males or juveniles (Martin et al. 2014).

What can be done to protect the platypus?

  • Ensure that water-sensitive urban design principles are always adopted in the development of new housing estates, shopping centres, industrial parks, etc. to reduce the impact of associated run-off on creeks and rivers.
  • Ensure that run-off from sealed roads in suburban or country areas drains to vegetated swales as opposed to concrete drains leading to waterways.
  • If you live in an area serviced by conventional stormwater drains, install a home water tank so rain falling on your roof can be stored and used to water the garden, top up ornamental pools or flush the toilet.
  • Choose permeable materials (such as loose gravel or porous paving) as your preferred option when developing low maintenance surfaces outside your home. Ensure that any areas of bare soil are covered by gravel or organic mulches so they don’t erode.
  • Whenever possible, direct run-off from areas of concrete or hard paved surfaces (or gutter downspouts) to flow towards a garden bed or lawn rather than to a street or concrete drain.

Photo: APC

Literature cited

Martin EH, Walsh CJ, Serena M and Webb JA (2014) Urban stormwater runoff limits distribution of platypus. Austral Ecology 39, 337-345.