Wellington homeowners with leaky drains could soon face heavy repair bills as the city council investigates ways to stop stormwater entering the city's sewerage system.
Surplus stormwater has the potential to overwhelm Wellington's sewerage system, sometimes causing it to overflow into the harbour and Cook Strait.
It is estimated about half of the stormwater gets in through faults in the council's sewerage mains and the other half via holes, cracks and faulty joints in private drains.
Council engineers and consultants will spend the next three months investigating ways to deal with fixing the holes and cracks.
The options are wide-ranging but expensive and include requiring private owners to upgrade or replace private drains.
The cost to property owners to carry out repairs could range from $1,000 to more than $20,000. The average cost has been estimated at between $4,000 and $7,000.
Council staff will report back with their findings in March.