She said the committee was aware the district council had serious issues to deal with that must be a priority, "but in saying that we must also not allow other concerns to fall behind".
She said the rubbish was "not a good look" for the riverbank walkway, or the very popular fishing platforms and beach and surfing area.
"A disappointing trend we've noticed is that people observe others dumping household rubbish but don't bother to follow it up."
Mrs Douglas said the residents committee was also concerned about graffiti and weeds in the space between the stopbanks and the river, which, she said, was Horizons' responsibility.
"We often find offal and fish remains over the bank in this area," she said.
She sent her complaints - and pictures - to a number of district councillors and Councillor Jack Bullock said the illegal dumping had to stop.
Mr Bullock said the council needed to put up a small reward of a few hundred dollars "to catch who's dumping this and make an example out of them".
He said a reward might prompt witnesses to come forward with information.
"How could people stand by and watch while people are littering our environment where we walk, play and enjoy time with people?"
Mrs Douglas said the issue of illegal dumping had been brought up at nearly every community meeting held in Castlecliff.
"I know this sort of dumping happens elsewhere, but this is a part of the city where a lot of people visit, including out-of-towners," she said.
She said the dumping happened randomly but was often seen in the Gilberd St area in front of the sailing club and behind the fishing platform and the Morgan St carpark.
"Over Christmas there were bags and bags of household rubbish dumped in the carpark," Mrs Douglas said.
