Council's acting sustainability manager, Hugh Cross, said council equally split the cost of providing the shower heads valued up to $199 full retail with Hunter Water.

"It's complicated because Hunter Water is part of a wider alliance but while we obviously know what we're [the council] are up for, we've been asked to keep it confidential, though I've no idea why," Mr Cross said.

"What I can tell you is the operation was extremely successful. We were inundated with people and in a few hours we provided 270 replacement showerheads for 200 homes. Some paid $30 for the top of the range $199 unit," he said.

"We recycled the old showerheads and raised $440 which will be used to help a third world country with water problems."

But not all residents were thrilled. Some waited in the queue only to be told the new unit couldn't replace the old one they had brought in.

"The new units were designed to fix directly to the male threaded outlet on the wall. Showerheads on the end of flexible pipe need a female thread. We will try to have some suitable adaptors available at the next one," Mr Cross said.

The last showerhead head exchange in this program will be at Belmont Community Hall on Saturday from 9am to 1pm.

'You will need to complete an application form (download it from www.lakemac.com.au) Take your old shower head complete with arm, plus proof of address and water connection.