"That will take many forms – on different issues,we'll have to adopt different strategies – but I'm not going to back down over this stuff.
"I wasn't elected to be a bureaucrat or a puppet for the corporate sector. I'm actually here to stand up for residents and that's what I'm going to do."
Mr Sri said he planned to introduce a system of"deliberative democracy"with the residents of The Gabba.
"What's going to distinguish our job here in The Gabba ward is that we're going to spend a lot of time listening to ordinary residents and actually doing what they tell us to,"he said.
"That's a marked break from what we've seen in mainstream politics here in Brisbane in the past.
"This is a significant shift from the political status quo – we're not just going to survey residents and then go off and do our own thing,we're going to give them meaningful control over what happens in their areas.
"It's not going to be easy – I'm not going to pretend it will be a simple task – but it's important that we shift the power balance because,right now,the big end of town has far too much influence over city council and I'm here to change that."
Mr Sri acknowledged the work of retired Labor councillor Helen Abrahams,who received 45.12 per cent of the 2012 primary vote,compared with Greens candidate Gary Kane's 17.7 per cent.
On the counting completed on Wednesday afternoon,Mr Sri had attracted 31.48 per cent of the primary vote,compared with Ms Lessio's 30.21 per cent.
"Helen had a really strong personal vote,but the size of the swing we've seen here is not just about Helen Abrahams retiring,"Mr Sri said.
"The size of the swing we've seen here is a positive endorsement for the policies that we were pushing forward.
"This is bigger than one councillor retiring and a shift to the left – this is a substantive shift. This is a significant quantum leap in the sort of politicians that the people of the inner-southside want to represent them."
Senator Waters said the Greens hoped to capitalised on its performance in the Brisbane election in the upcoming federal poll.
"In the federal arena,we'll be running a really strong,full ticket in Queensland,"she said.
"There will be a Greens option in every single seat,there'll be some great candidates on our Senate ticket and we're really excited about giving the people the choice to vote for their values."
In the event of a double dissolution election,former Democrats leader Andrew Bartlett would join Senator Waters on the ticket.
In a half-Senate election,the second on the Greens ticket would be 2016 Brisbane lord mayoral candidate Ben Pennings.
State Labor Environment Minister Steven Miles said the Greens'Gabba victory showed Labor needed to ask itself some questions about the Brisbane council campaign.
"I do represent an area that is concerned about environmental issues and I think this emphasises the need for Labor to be good on environmental policy and that's something we have a proud record of doing,"he said.
- with Amy Remeikis