Matt Cowley Tauranga City Councillor

Few people know Tauranga's streets, canals, and reserves are designed to flood during heavy rainfall events. These assets try to hold the water away from homes until it drains away.

Flooding is one of many natural hazards likely to strike Tauranga. But it would bankrupt the city providing absolute protection from all natural hazards. There will always be some events where council cannot protect you.

The new subdivisions built during the last decade provide protection up to a 50-year Average Recurrence Interval event, which protects these houses from most rainfall events.

The problem lies with the well-established suburbs, which have maximum protection levels ranging between two and 20-year ARIs.

Council has assessed different options for providing fair flood protection levels across the city. Note we have just focused on protecting habitable floors – living areas only, not garages or other storage sheds.

We estimate it will cost $190 million to provide at least a 10-year ARI flood protection level across the city – benefiting around 475 houses. It could cost $300m to provide a 50-year ARI to match the same protection level as the new suburbs.

Each $10m of increased capital expenditure triggers an additional $550,000 in operational costs. Council's current stormwater-related debt is $98m and we already spend $15.4m operationally each year.

Because of these extreme costs, council's draft Long Term Plan proposes to focus on safety. Council would intervene if flood waters were deep enough or going fast enough near houses to be a safety risk to children or elderly.

Council proposes to continue to use a mixture of debt and the rates stormwater levy to provide urgent works where people's safety is triggered. Council would also build up a reserve fund to respond where it's needed in the future.

Individuals would be required to protect their own properties through new rules in the city plan.

It could require properties to be raised and have stormwater storage tanks on-site, depending on how much of the site is covered by impermeable surfaces.

I was the only elected member to vote against this approach. The heavy rules approach could take up to 75-100 years for owners to change their properties.

The rules approach would be slow to adjust for ever-increasing rainfall intensities and climate change. Fixing one property could aggravate problems for neighbouring properties. Fixing individual properties won't replace the need to pump stormwater away in low-lying areas.

Feel free to email me your thoughts (matt.cowley@tauranga.govt.nz), call/text me on 027 6989 548, and follow me at www.facebook.com/a.younger.voice.