OK, having a bypass facility on a wastewater treatment plant is a pretty normal design feature, because while untreated sewerage going into waterways is a Bad Thing, blocking up the biological processes of the plant, or leaving wastewater in a holding tank so long it goes toxic are also Bad Things, of greater magnitude. Having said that, how often the bypass facility is needed is a big deal. From Christchurch CC's website, they have a programme to reduce rainwater infiltration into their wastewater network, which will help; but you could ask them to consider treating the bypass line with UV to kill bugs before they get into the waterways; or doing their infiltration upgrades faster; and/or upgrading their treatment plant to take a greater capacity.

The resource consent process isn't the end, either. People can always write into the Council about things they care about, or contact their ward councillors directly, or respond to specific consultation exercises. I strongly recommend that people make submissions about this for the Draft Long Term Plan (LTCCP) consultation, which closes on 16 April. (http://www.ccc.govt.nz/HaveYourSay/ConsultationView.aspx?ConsultId=611)