The increase is one of two options being released to Cantabrians in the region's draft Long Term Plan.
Using the environment as a reason to raise Canterbury's regional rates take by more than 24 per cent is being questioned by Harewood Ward city councillor Aaron Keown.
ECan said the average total rates each property would pay under 'option 1' next financial year was $591.10 - compared to $455.04 in the current 2020/21 year ($136.06 increase).
Environment Canterbury says it needs to fund central government programmes which demand that waterways be cleaned up from farming and industrial waste.
Changes to transport are also cited as a growing cost to the region.
But Keown says ECan is not tackling climate change in a logical way.
Listen to Keown here:
The New Zealand Federation of Freshwater Anglers has also come out swinging over the proposed rates increase.
A federation spokesperson said it "is appalled that the largest and best resourced regional council in New Zealand should propose rate increases of 24% or 18% to meet its obligations under the August 2020 National Policy Statement for Freshwater Management".
"Over the past two decades, ECan’s management of the region’s freshwater could best be described as 'active mismanagement'.
"Ecan facilitated the region’s massive irrigation development in order to increase GDP while disregarding the nitrate pollution they knew would inevitably occur
