Home Page About the Trust Home Page Flood Mitigation Home Page Sustainable Water Home Page Water Quality Home Page Vegetation Home Page


Causes of poor water quality


Issue Source(s) Associated Problems in Creeks
Sewage Pollution
  • sewer overflows
  • leakage from mains and private sewer lines
  • pathogens including bacteria (eg. E.coli) and protozoa (eg. Cryptosporidium and Giardia) may be released into creeks, posing a risk to human and animal health
  • nutrients
  • chemicals such as detergents
  • an increase in total dissolved solids, including salt
  • endocrine disrupting chemicals (EDCs) may be released in sewage, with the potential to affect important functions in the human body
Oils, grease and other chemicals
  • industry
  • motor vehicles
  • poor disposal of domestic wastes
  • toxic to aquatic life, destroys food chain
  • kills plants and animals
  • chemicals take a long time to break down
  • fertilizer run-off
  • sewer overflows
  • stormwater
  • increased growth of algae and weeds leading to low oxygen levels
  • changes to food chain
  • car washing
  • sewer overflows
  • stormwater run-off
  • harmful to aquatic life
  • adds nutrients
  • increases turbidity of water
Litter and rubbish
  • shopping centres
  • domestic waste
  • illegal dumping
  • wind
  • stormwater run-off
  • roads
  • unsightly
  • adds chemicals to creeks
  • harmful to animals
  • encourages weed growth
  • dumped rubbish
  • upstream infestations
  • birds and wind
  • stormwater
  • loss of native flora and fauna
  • changed nutrient cycling
  • changed light conditions
  • changed stream dynamics and sedimentation
  • development sites
  • erosion
  • stormwater run-off
  • increased turbidity
  • in-filling of creek pools
  • weed growth
  • stormwater run-off
  • illegal dumping
  • spray drift
  • toxic to aquatic life
  • long persistence in sediments
  • harmful to human health
Changes to creek flow
  • reduced vegetation and increased paved and impermeable surfaces in urban areas
  • erosion
  • steepens creek channels
  • widened creeks and damaged creekline vegetation and sedimentation downstream



Trust logo