Included in the shopping list are four mobile generators costing $140,000, five fixed generators at critical pumping stations for $1.4 million and a three year $630,000 program to fit 295 pumping stations with quick connection equipment.

Water Corporation general manager Graham Cargeeg said there were only four sewerage spills in the past year and that overall blackouts are only responsible for 15% of spills, the worst of which resulted in 500cu metres of effluent running into the Swan River.

The back-up generators are another slap in the face for Western Power, which is currently trying to restore confidence in the state power system after a disastrous year that saw the utility blamed for the death of two women and rolling blackouts across Perth in the summer.