0:00

Now in the low-lying Netherlands there

0:02

is a program called Room for the

0:04

River, which is helping shore up against

0:06

flooding in a way that's a far cry from putting

0:09

a mythical finger in the dike. Now

0:11

giving a room, rather room

0:13

to a river, to flood safely

0:16

rather than hem it in with man-made

0:18

engineering like stock banks has

0:20

helped the Dutch mitigate against flooding

0:22

since the early 2000s. Now this week Climate

0:25

Change Minister James Shaw tasked

0:27

a select committee with investigating

0:30

how communities can adapt and

0:32

relocate in the face of severe

0:34

weather events. One option,

0:37

according to my next guest, is to

0:39

look to the Dutch to accommodate a river

0:41

prone to flood and keep communities

0:44

out of harm's way. Tom Kay

0:46

is a freshwater advocate for Forrest and

0:48

Bird. He's touring the country and this

0:50

week gave us 28th out of almost 40

0:53

Making Room for Rivers presentations

0:55

to communities and local

0:57

government groups. Keen to hear how

0:59

going with the flow can manage flood

1:02

risk and preserve the river's ecosystems.

1:05

And Tom joins me in the Wellington studio

1:07

now. Welcome to the program Tom. Kia ora, thank

1:10

you for having me. Great to have you. Now

1:12

you have just presented to Ash

1:14

Burton, which of course we

1:16

will know has had quite a few

1:19

flooding issues. Talk us through

1:21

your presentation.

1:22

Yeah, we have just been down in Canterbury

1:24

actually, Christchurch, Ashburton, Timidou and

1:26

in front of the regional council down

1:28

there. Really good turnouts, particularly

1:31

in Ashburton. Obviously, as you say, they were

1:33

hit pretty hard by flooding. Basically,

1:36

we're taking this conversation to

1:38

communities to kind of explain

1:40

to them what we've done to our rivers historically through

1:43

time. We've hemmed them in, we've

1:45

taken space away from them, the space that

1:47

they needed to function properly to do

1:49

things like recharge groundwater, but

1:52

also to flood safely. And

1:54

we're sort of trying to

1:56

get that across to communities so

1:58

that they can appreciate.

1:59

why this is happening when places

2:02

flood they can see you know where the river used

2:04

to be and where it might go in the future

2:06

and and sort of understand why it is

2:08

that they're spilling out into the places that

2:10

we now live.

2:12

Okay and your family were

2:14

in Terradale when the cyclone Gabrielle

2:16

happened. What happened there? Yeah

2:19

so Terradale is a suburb alongside

2:21

the Toutacouti River in Hawkes Bay and on

2:24

that morning of the cyclone the Toutacouti River basically

2:27

rose up to one of the highest flows recorded.

2:29

It took out the flow gauge 1800 cumex

2:31

so 1800 tons

2:34

of water was flowing down that river per second

2:37

and basically the river couldn't hold it anymore.

2:40

It overtopped the stop banks upstream and

2:42

Pukitapu and Dartmoor and flooded the valleys there

2:45

and then started to spill into the streets of Terradale

2:47

which as you say is where my family lives and

2:50

they were all evacuated everyone in the suburbs

2:52

nearby the river. Thankfully they

2:54

were okay my family but of course others

2:56

weren't so lucky and

2:59

yeah a lot of people heavily impacted by

3:01

that the river basically just didn't have the space it

3:03

needed to to hold that water and

3:05

it spilled out everywhere.

3:07

And of course this is happening

3:10

throughout New Zealand well and around

3:12

the world but so and what are

3:14

we doing? What are we doing wrong? We are trying to

3:16

control these rivers aren't we? We're trying to build

3:19

the stop

3:19

banks which ultimately

3:22

they don't work Yeah so as

3:24

our kind of call is often still in communities

3:27

to you know to put the river back where

3:29

it was you know and and that's just

3:32

unfortunately it's not that easy and it's not even

3:34

true the rivers aren't

3:36

fixed things they're trying to move

3:39

and adjust all the time to everything that's happening

3:41

upstream all the sediment that's coming down the gravels

3:43

were a younger road in country all

3:45

the rainfall and they're

3:47

just trying to adjust to that and to kind

3:49

of

3:50

think that we are controlling the river is is

3:53

a bit of a myth with historically

3:56

you know you only have to look back not very long through history

3:58

and see every couple of decades there's usually a big

4:00

flood in different towns and

4:02

we kind of forget that those floods have happened.

4:05

We say, you know, build

4:07

the stop banks higher, put the river back

4:09

where it was and we do that and then we get

4:11

hit again and we usually get hit harder.

4:13

So for instance, Tarradale, they had just made

4:17

their stop bank bigger, higher, stronger,

4:20

that arguably saved

4:22

some of Tarradale from the worst

4:24

of the impacts but that stop bank was still overtocked

4:27

by the flood and when we have higher

4:29

stop banks, those waters behind the stop bank are

4:32

flowing faster, they're deeper because the stop

4:34

bank is higher. So then when the water comes

4:36

over that stop bank or bursts or

4:38

cuts over it or bursts through it or anything like that,

4:41

it comes out of that channel with huge amounts

4:43

of energy, you know. It's sort of physics 101. You

4:46

pick up a ton of something and you lift it

4:48

and it gains gravitational potential

4:49

energy. So you pick up a ton of water

4:52

or tens of tons or hundreds or thousands of tons

4:54

in these cases and then you drop

4:56

it onto a floodplain and it just takes

4:59

huge amounts of energy and we see that devastation

5:02

across the floodplains of Hawkes Bay,

5:04

for example. So yeah.

5:06

So what do you do in

5:08

a situation like that because you

5:10

can't keep on building the stop banks higher, can

5:12

you? Yeah, exactly and that's exactly what they realized

5:15

in the Netherlands basically. You know, we talk about flood

5:17

protection systems in terms of maybe

5:20

a one in 20 year stop bank or a

5:22

one in 100 year stop bank, that idea of, you

5:24

know, 1% chance every year say that the stop

5:26

bank will be overtopped. In the Netherlands

5:29

they talk in like one in a thousand years. So

5:31

they realized we can't just keep building these walls

5:33

higher and higher and, you know, there's

5:35

just no way that we can face the impact

5:37

of that if those are ever overtopped. So they came

5:40

up with this, well, you know, to come

5:42

up with it, I don't know, but they kind of credited with doing

5:45

this on a big scale, making space in those channels,

5:47

you know, moving the stop banks further away, moving

5:50

people out of high risk floodplains and

5:52

giving the river the space it actually needs to

5:55

adjust and flood and things like that. There's

5:57

some studies that were done afterwards that basically found

5:59

a few... If you could lower the level of a flood

6:02

in a river by 50 centimetres, you

6:04

could reduce the potential or the probability

6:06

of failure of the stop banks by 10 times. So

6:09

just that little bit of extra width to lower

6:11

those floodwaters means that the likelihood of them

6:13

bursting is just so much lower. And then

6:15

you save money in the long term, right? We spend so much

6:17

money building stop banks higher, putting

6:19

in rocks, we have to find those rocks, concrete,

6:22

all sorts of things like that. And then we

6:25

pay the cost again when it's overtopped

6:27

and we have all this damage to our communities. It's actually more

6:29

cost

6:29

effective and sustainable to kind of back

6:32

off a bit and let the river kind of adjust itself

6:34

and avoid throwing money at trying

6:37

to control something that we can't really control.

6:39

However, that is problematic,

6:41

isn't it? Because in so many places,

6:44

we have built right next to rivers. And

6:48

what are you proposing

6:49

that people move

6:52

out, that councils buy

6:54

the land back?

6:55

Yeah, well, it will

6:57

be a conversation like that in some places and

6:59

it already is, you know, Cyclone Gabriel is

7:02

an example of that. But it's not something that we're

7:04

saying has to happen overnight or straight away.

7:07

And in a lot of places, we

7:09

have space alongside some of our rivers, some of the

7:12

land and the floodplains and as

7:14

council and land, for example, it's public land. But

7:16

yeah, other places we have hemmed in and we're going to have

7:19

to have some serious conversations about

7:21

how maybe we do move away over time,

7:23

or at least if we're not moving away, we're not making the problem

7:25

worse. We're not putting more people in behind those

7:28

stop banks and things because stop banks have

7:30

this. This is a bit like when you build

7:32

a road and more cars come, you know, you build

7:34

stop banks, more people move in behind

7:36

it. We develop in behind those stop banks

7:38

because we have this perception that they provide

7:41

this level of protection that we just provide

7:43

for every flood. And that's just totally

7:45

untrue. They're only designed to, you

7:48

know, protect us to a point and even then they

7:50

can fail.

7:51

So we have to kind of get

7:53

away from that idea that these are these perfect things

7:55

and we have to start looking at how we can get

7:57

people out of harm's way, you know, reduce the risk. other

8:00

benefits with that as well, the health of the river, the

8:02

health of our groundwater, the health of our communities,

8:04

our resilience, you know, all the disruptions that

8:07

we've faced from flooding, all that kind of

8:09

starts to go away when we can give rivers a little

8:11

bit more room.

8:12

And that is happening in some

8:15

places. I think there's a really good example

8:17

in your presentation about Wellington

8:19

and the Hutt. Tell us what happened there.

8:21

Yeah, so Greater Wellington Regional Council, you

8:24

know, heavily developed floodplain with Tiawakai

8:26

Rangi, the Hutt River, so Upper Hutt, Lower Hutt,

8:28

Patawni, all in the floodplain really.

8:31

And the Hutt River has been squeezed through time, it's been

8:33

narrowed and it's had space taken away from

8:36

it and it's got stock banks kind of lining it and a

8:38

lot of people will be familiar with that. Greater

8:42

Wellington Regional Council identified this pinch point

8:44

in the river down at Melling, basically

8:46

the narrowest point and if the river overtopped the

8:48

stock banks there it would do over a billion dollars

8:50

worth of damage. You know, there's something like 600 houses

8:53

and five schools and you know, crazy

8:56

amounts of damage would be done. So the council

8:58

basically got in at the same time as Wakakotahi

9:01

NZTA doing some work on some bridges

9:03

and things. When actually we're gonna make some more

9:05

space for the river here, we're gonna widen it. They bought

9:08

a whole bunch of properties on one side of the river, spent

9:11

about a hundred million dollars I think as I understand

9:13

it and acquired these properties and

9:15

are moving people out basically

9:18

and turning that back into green space. And

9:20

people were okay with that, they went along with that,

9:22

they gave those people time and warning and said

9:25

hey look you can stay for a bit, we're not gonna start it yet. You

9:27

know, and this project should be

9:29

starting sort of this year, they've got all the consents and everything

9:31

to widen the river by 90 meters. They're

9:33

gonna build the stock bank higher on the on the

9:35

lower huts side as well, so it's sort of a combination

9:38

of things but they're also gonna try and turn lower

9:40

hut back to face the river so that people remember

9:42

that they live on a floodplain you know and they connect with that

9:44

river again.

9:45

Now river channels

9:48

also adapt to tectonic changes,

9:51

don't they?

9:53

Yeah well there's some, a

9:55

lot of interesting work around this stuff being done with

9:58

um

9:58

you know the potential for say an earthquake

10:01

to just massively shift a river

10:03

channel and have that river revolve and jump

10:05

and change its course in the floodplain.

10:08

Yeah, crazy stuff could happen.

10:10

These rivers aren't going to stay in one place forever. It's

10:13

farceable to think that.

10:15

Okay, so looking

10:17

at New Zealand, what are some

10:19

of the rivers that give you the

10:21

most concern? Yeah,

10:24

I mean, these

10:25

big braided rivers on

10:27

the east coast, for example, I think are really great examples

10:30

of where we've encroached and squeezed

10:32

these rivers way too hard.

10:34

And there's

10:36

also a lot of potential to undo that really easily.

10:39

You know, we haven't

10:40

developed really intensely, like

10:43

we have, for instance, in lower Hutt and

10:45

Patawhnee. And there's a lot of potential

10:48

to give some space back to the river there. And there's

10:50

a lot of hope there. And there's huge potential

10:52

then for fish and macro invertebrates and birds to

10:54

have those areas back that they need to

10:56

live. We've got 76% of our fish

10:59

species are threatened. We've got

11:01

so many threatened bird species. Groundwater

11:04

levels are dropping in these places, they're going to get drier.

11:07

You know, we could do great things to

11:10

restore these ecosystems and kind of benefit everyone

11:13

and us from an ecological perspective, but also

11:15

from a flood resilience perspective.

11:17

So I see great potential there. But for example, Hawke's

11:20

Bay is a great example of the Ngaru Doro

11:22

and the two Taikuri rivers, which you know, both overtopped.

11:24

They come together at the coast and create this

11:26

kind of V. And we've stop banked them on

11:28

both sides, which made this big bathtub

11:31

area basically when the rivers jumped

11:33

out of their channels and filled the space on the inside

11:35

of a stop banks, they created a swimming pool

11:37

that drowned people's houses, you know, people were

11:39

being rescued off rooftops. And those

11:41

are the places I think is priority places

11:44

that we really need to look at. Should we be

11:46

there? Maybe we want to be there farming and things like that

11:48

or whatever, but should we be putting people in

11:50

potential harm's way and putting them back

11:52

there after these events as well. And

11:54

yeah, I hope the answer is no. Yeah,

11:57

but there are big cost factors involved.

11:59

involved in moving or managed

12:02

retreat. I saw

12:04

your presentation to the Auckland Council

12:07

and well, you got

12:09

a round of applause from the Mayor himself,

12:11

who is of course an engineer. The

12:15

big question was how much is it

12:17

going

12:17

to cost and your

12:20

response was quite good. Yeah, well, I

12:22

can't remember exactly what it was, but the

12:26

key thing to remember here is that the cost

12:29

of not doing something is always going to be more.

12:32

You know, the cost of insurance

12:34

payouts from the Ashburn floods was something like 40 to 60

12:37

million dollars or something. And then we had Nelson

12:39

and then we had Auckland and then we had cycling Gabriel and the

12:42

cost of that's nine to 14.5

12:44

billion or something, treasury estimated. And I don't know if

12:46

that includes the then social costs, the

12:49

disruption to people's lives, the anxiety. And

12:52

then we're going to see that again and again and again. And,

12:56

you know, we can front foot that.

12:59

Yes, it will cost in some places

13:01

to retreat, to back off, to give rivers more

13:03

space, but we also save money in terms of maintenance.

13:06

You know, we save money on all the constantly

13:08

getting in there with willows and concrete and rocks. That's

13:11

expensive. That's a lot of work. And

13:14

then the cleanup is just enormously

13:16

expensive. So, you know, we're in

13:18

this together. This affects all of us.

13:20

Everyone knows someone who was affected by flooding. Everyone,

13:24

you know, a lot of people were directly

13:26

affected by this flooding and we keep

13:28

paying the cost. We pay it over and over,

13:31

whether it's through our insurance premiums or our rates

13:33

or whatever. And we'd be much better off getting

13:35

together and, you know, paying in advance

13:37

together, helping each other, helping

13:39

our rivers and giving them

13:42

back their money and making our community safer

13:45

at the same time.

13:46

What has the response

13:48

been like, Tom, you've presented 28

13:51

councils or areas. What

13:53

sort of response

13:54

are you getting? Yes, so we've presented mostly

13:56

to communities, but also most of the regional councils

13:58

so far and the The reaction

14:01

is overwhelmingly, I would

14:03

say positive, but it's kind of,

14:05

you know, it's realistic. People understand

14:08

once they see how we've managed our rivers, the

14:10

space we've taken, where they used to flow, they

14:13

appreciate why this is happening and they

14:15

appreciate all the unintended consequences.

14:18

And no one really pushes back against

14:21

that because it's, you kind of can't

14:23

argue with what we've done and what's happening. And

14:26

they kind of get that something has to change. And

14:28

there is a reluctance to or

14:31

an uncertainty about where we go next. You know,

14:33

what is the cost? Who pays

14:36

or do people need to pay? You know, what are our priority

14:39

areas?

14:41

But everyone kind of accepts that something has

14:43

to change. And I think

14:45

that's a really positive

14:47

way to start the conversation. And I think now

14:49

we need to get people to understand that next part,

14:51

which is actually we all win from doing

14:53

this. We all win. We might win in the economic

14:55

sense, but way wider than that. We win

14:57

from a social perspective. The ecosystems

15:00

will be healthier. Our communities will be much

15:02

more resilient and our rivers will be much more

15:04

healthy, beautiful places to go.

15:07

Yeah. Do you think that we're going

15:09

to be brave enough to make these decisions

15:11

before another disaster

15:14

strikes?

15:14

Yeah, that's a really good question. And

15:16

I worry that we're not. And

15:19

the thing that I worry about with us not

15:21

being that brave is that if we

15:23

aren't brave enough, if we don't make these decisions

15:26

to manage our rivers differently, I say

15:28

manage our rivers, we're never really managing our rivers.

15:30

We think we're in control for a couple of years and then they

15:32

get the better of us. You know, if we

15:34

can't learn to live with our rivers in a way

15:36

that's more sort of respectful or

15:38

whatever you want to say, then

15:41

they're going to make that choice for us. They're going to they're

15:43

going to take back the space they need to flood because

15:46

that's what they do. You know, resilient rivers, they need

15:48

room to be resilient. That's

15:51

not a concrete river or stop bank that is

15:53

a resilient river. It just bursts out of its banks

15:55

when it gets a big enough flood. Resilient rivers

15:57

need room and flooding rivers.

15:59

take that room. So if we don't

16:02

have that conversation about where that water is going to go, then

16:04

those rivers will take it.

16:05

So we need to transform our thinking. We need

16:08

to make that room for these rivers. And

16:10

we've got a massive opportunity coming out

16:12

of the cyclone to do something different. There's someone that says, you know,

16:15

there's never a cheaper time to

16:17

retreat than straight after a disaster because

16:19

otherwise you're just throwing money into something

16:21

again that's eventually going to be taken away. So

16:24

now is the time to transform our thinking and make

16:26

some room for rivers.

16:27

Brilliant, Tom. Hey,

16:30

Tom Kay, thanks so much for joining us and

16:33

talking us through making room for

16:35

rivers. I hope we can be brave enough

16:36

to make this decision. Thanks so much for coming

16:38

in. Thank you very much.