Flooding at Meola Creek

Meola Creek in flood in 2008 The swollen creek in heavy rain carries a nasty soup of heavy metal and sewage – and most of it ends up in the Waitemata Harbour. Flooding pictures this page: STEPS. Picture on ‘Big issues’ opening page is of Oakley Creek in flood, taken by Wendy John.

When it rains, the water slips from roofs, roads and land and disappears down drains, doesn’t it? Everything’s fine as it soaks into the ground or ends up in creeks and out into the harbour. What’s wrong with that – it’s clean water isn’t it?

Well, no it’s not. The stormwater dumped into our creeks and harbours is one of the city’s greatest problems and Mt Albert is in the thick of it. Waititiko Meola Creek has its source in this suburb and is the biggest single contributor to the pollution of the Waitemata Harbour, which has about 2.2 million cubic metres of sewage and metal-laden stormwater dumped into it each year.

Elizabeth Walker, chair of STEPS, at Meloa Creek in Mt AlbertElizabeth Walker (pictured), chair of the St Lukes Environmental Protection Society (STEPS) argues here that we need to stand up and persuade Auckland Council to start treating stormwater with the seriousness it is giving to transport.

STEPS, with groups like Manukau Harbour Restoration Society and Friends of Oakley Creek Te Auanga, has been battling waste and stormwater issues for years. STEPS was founded in 2005 by Pat Prescott and a group of local residents who were frustrated by constant sewer overflows from inadequate sewage and stormwater systems, while ongoing development around St Lukes added to the volumes. 

This year STEPS linked up with a wider Auckland group SASOC (Stop All Sewage Overflows Coalition) to ask the council to face the stormwater issue. Mt Albert Residents’ Association (MARA) has recently joined SASOC.

Elizabeth says we must be prepared to pay for the omissions of the past in dealing with the stormwater problems of the present and future.

If we don’t take a stand and our civic leaders and bureaucrats decide to fund only transport projects, then our children, and their children, may find that a day at the beach becomes a foreign concept in Auckland.

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[UPDATE, November 29: Mayor Phil Goff’s 10-year budget provides for a targeted rate to improve water quality – costing about $1.70 a week for an average household. Most of that will go toward speeding up the $1b-plus Central Interceptor pipeline through Mt Albert to the Mangere wastewater treatment plant, reducing overflows into the Waitemata Harbour within 10 years – 20 years earlier than planned.]

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What is stormwater?

Stormwater is a part of urban living. While rainfall in nature is dealt with by wetlands, rivers and natural water features, hard urban surfaces collect rainfall which must be disposed of.

So how does Auckland deal with it?

The Auckland Council Unitary Plan now has good standards for “green-fields” (new) development in outer areas.

However, in parts of Auckland isthmus the stormwater infrastructure and pipes are from the 19th century. That means places like Mt Albert – where the council wants “brown-fields” development – need a major retrofit of poor or non-existing stormwater infrastructure first.

What exactly is the “Stormwater Problem”?

Stormwater washes sediments and heavy metals (created by hard – impervious – surfaces like roofs and roads) into harbours and creeks. The resulting impact: declining wildlife and water quality.

The main problems are:

  • Auckland roads, which generate half the stormwater volume and collect most heavy metals.
  • Combined sewers on the Auckland isthmus. Stormwater flows into sewerage pipes, where it mixes with raw sewage, then flows into creeks and harbours whenever it rains in Mt Albert or elsewhere.
  • Soakage to the aquifer on Auckland isthmus. Auckland’s largest underground water source should be pristine. Currently untreated stormwater is soaking in containing pollutants which will last for decades or centuries.

The severity of the problem in Meola Creek, Mt Albert, is shown here in this 2010 graph from the council:

Meola Creek carries about  one million cubic metres per year of sewage and metal-laden stormwater  into Waitemata Harbour.

Meanwhile, Mangere Waste Treatment plant is by far the largest fresh water river flowing into the saline Manukau Harbour, causing different kinds of problems, to add to existing western stormwater issues.

In the future, the Unitary Plan will effectively raise impervious surfaces from 42% to 62%. Our harbours simply cannot cope.

What is happening now?

Auckland Council knows the high-risk beaches /locations with ongoing water quality issues, where swimming or recreational water activities are not recommended. Clearly this is not just an urban issue because the sites include Cox’s Bay, Te Tokaroa (Meola Reef), Weymouth Beach, Little Oneroa Lagoon, Wairau, Piha lagoon outlet, North Piha lagoon, Wood Bay, Laingholm Beach, Te Henga (Bethells) lagoons.

The council has a visual simulation model which shows what happens now after a sewerage overflow: the sewage sits in the water, tides go in and out… and it remains. It can take several days to flush out to the open sea and, while it sits in concentrated levels, is dangerous to both human health and to wildlife.

Link to the “Safe Swim” program which now alerts people to the danger, with the council forecasting and publishing the quality of beach water.

Flooding along the Roy Clements Treeway in Mt AlbertWho would benefit from clean Auckland harbours?

Yachties, swimmers, families and citizens generally would not have to deal with the sanitary items and coliform counts that regularly show up on Auckland beaches, parks and in the water.  So most Aucklanders and many other New Zealanders would gain from treating and separating stormwater.

What do we want?

Auckland stormwater impacts are heritage problems no one wants to pass to future generations. We believe stormwater can no longer be a buried problem.

The council has under-invested in handling stormwater, especially when it comes to roads, combined sewers and soakage.

Clean water infrastructure must receive the same planning, funding and attention in the Auckland plan that is being given to transport.

The old stormwater infrastructure gaps pose major health risks to humans and the environment, and people living on the Auckland isthmus deserve similar standards to what is being built as Auckland expands into those new “green fields”.

We want the council to start on stormwater treatment and wetland pilots immediately – and the STEPS wetland in Mt Albert’s Roy Clements Treeway is an example of how much nature can do to treat water and recharge the aquifer if the council can just slow the flow.

What is the plan?

Watercare plans a central interceptor – a wastewater tunnel that will run between Western Springs and the Mangere Wastewater Treatment Plant. It will run underground for 13km, will cost around $1 billion and is intended to:

  • Provide for the future growth of Auckland;
  • Reduce overflows to the Waitemata and Manukau harbours by 80% in some areas.

For more information and a video,  follow this link .

How will the Central Interceptor affect Mt Albert?

In Mt Albert there will be several vertical shafts built up to 50m below ground, to connect with the interceptor tunnel running underneath the thick layer of basalt lava rock.

One shaft will be in the grounds of Plant and Food, behind Haverstock Rd.  Another will be in the middle of the Roy Clements Treeway where all the trees near St Lukes Megacentre will be cleared to allow the work to take place starting in 2021. The number of floods on Meola will reduce as a result.

But is that it? What about stormwater?

Additional work is needed to treat stormwater, and the council is yet to announce details. It may include some sewer separation and some local treatment to reduce the volumes of stormwater flowing through the sewers. Stormwater treatment needs to occur as near as possible to where the rain falls.

The good news is that unlike sewage treatment or flooding control it can be done progressively

In October 2017 the council’s environment and community committee voted to consider the proposed stormwater infrastructure proposal for the western isthmus as part of the long-term plan consultation in February next year.

The Roy Clements Treeway with swollen Meola CreekThe long-awaited proposal for stormwater and wastewater work around the planned Central Interceptor includes stormwater separation, a wastewater tunnel from Grey Lynn (Cox’s creek) and stormwater treatment.

But there is a lot of water to go under the bridge before a decision is made and a commitment is given. Stormwater needs powerful advocacy.

So isn’t the issue pretty clear?

Well, no. Auckland Council has spent money previously budgeted for stormwater upgrades on other things. Auckland Council has a “debt ceiling” – a limit on the money it can borrow (and spend). Unless we stand up for clean water in our harbours this pattern of neglect will continue.

How big is the bill?

If Auckland Council cannot remove the large volumes of stormwater going to the Mangere treatment plant then Aucklanders may well have to pay Watercare Services to build more waste treatment capacity. That would cost billions.

How can it be funded?

Auckland politicians have mentioned a “targeted water quality charge” – and the benefits of that are clear: it can only be spent on stormwater; it cannot go to stadiums, the America’s Cup and lifestyle pursuits.

Who should pay?  

Aucklanders who enjoy beaches and water recreation… urban Aucklanders as the main road users (since heavy metals and oil and the largest amount of stormwater come from roads)…  Watercare waste treatment customers.

A government which cares about the health of people in NZ’s largest city – or about clean water, or about safe housing intensification – would also consider special purpose vehicles (SPVs) – like government bonds for urban NZ to catch up with its water infrastructure.

Let’s remember that 86% of New Zealanders live in cities and towns… and no one wants the next generation to be facing such a dreadful situation.

The next steps

The Auckland Plan refresh must contain aspirations and plans for water infrastructure, similar to those for transport. And the long-term plan must include “ring fenced” water funding for stormwater improvements on the Auckland isthmus.

Perhaps most of all, though, we need Aucklanders to stand up and say this issue is hugely important and needs to be sorted before it’s too late.

Things you can do, steps you can take: