$1.8m cannabis haul at hydro house

Nearly $2 million worth of cannabis has been seized during a raid on a house in the NSW Blue Mountains.

Police found 252 cannabis plants with a potential street value of more than $1.8 million at the hydro house in Wentworth Falls on Tuesday.

During their search, officers discovered eight rooms that were being used to grow cannabis plants along with a network of wires used to direct stolen electricity into the property.

"As a result of the hard work by Blue Mountains detectives we have shut down a hydro house and prevented a large quantity of cannabis from reaching the streets," Detective Inspector Dietmar Almer said.

The investigation continues and police expect to make arrests in the coming weeks.