Review the plans for a new tunnel under the river and let Thames Water know your views.
Thames Water wants to use the Alfred Salter Playground in Druid Street for two years while the tunnel is built. King's Stairs Gardens would also be seriously affected.
Specialists from the project team will be on hand to answer any questions you may have.
At 6.30pm on Tuesday members of the Save King's Stairs Gardens Action Group will be joined by campaigners from other greenfield sites affected by Thames Water's plans for a final rally.
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