High levels of faecal coliforms near Grafton associated with storm events . Stormwater runnoff from Grafton City - particularly in storm events when there are low flows in the river. High suspended sediment loads throughout the catchment in high flow events. Gully erosion in highly disperible soil types. Erosion from intensive agriculture.
Low river flows.
Nutrient discharge from towns and agriculture. High rate of water extraction from the river. Nutrient discharge from towns and agriculture. High levels of some heavy metals in Plumbago creek near Drake, particularly in the Sawpit Creek sub-catchment. Past mining activities.