Birthright Kāpiti manager Leonie Murch said, "It happened a lot when we were at the old building but it calmed down when we got here.
"But since lockdown it has escalated and is now happening multiple times a week.
"We have security footage of people dropping off rubbish from a truck and footage of people in the middle of the night.
"Adding to the problem are the next people who come searching through the stuff in the middle of the night, take what they want and scattering everything else.
"When donations come during the day that is rubbish and not quite up to our standard to resell, we are understanding that people have different standards and are polite and thankful that they thought of us," Amanda said.
"But this is blatant dumping and there's a huge difference."
Working in the community for the past 30 years, Birthright offers social services to its clients, in particular single-parent families, and helps a wide variety of people.
"We work so hard to raise funds to help people in our community and all the money stays in the community so the people dumping rubbish are taking away from people they probably know," Leonie said.
"We pay the same price at the tip as anyone else plus all the time and effort it takes our staff or volunteers to get it there.
"We average spending $8000 per year taking rubbish to the tip, and we're only a small opshop.
"We just want this to stop."