Recently I went for a walk through a hole.
That may not sound frightfully thrilling, but I found it really interesting!
That’s because I’ve watched the progression of this hole for weeks.
Down the road from where I live one of Napier’s main arterial routes, Taradale Road, has been getting dug up, had large metal plates and piles driven beneath it – the sound of the piledriver at times not too dissimilar to a church or clock tower bell (except I am unaware of the time “72 to 14 o’clock”..) and large concrete culvert blocks being lifted in and slid underneath it.
All this activity – The stuff of Tonka truck drivers and Lego builders’ dreams is to aid the flow of the Georges Drive creek and lessen the chances and effects of future flooding events along its path.
The creek has a long, aquatic pedigree. Before Hawke’s Bay’s 1931 Earthquake and subsequent urban development, the path that it takes from Chambers Street behind Napier Boys’ High School, along between Georges Drive and Douglas McLean Avenue and passing under Taradale Road, used to be the course of the Tutaekuri River that now flows behind Taradale.
On 9 November 2020 parts of Napier were inundated by flooding, much of which happened in the suburbs of Marewa and Maraenui, along this creek.
While where I live was fortunately spared from the flooding, it was only just so – because the river/creek bed is trapezoid shape, for every meter the water rose up, it had to go five, 10, 20 meters across – The creek level outside our house still got to within a meter of breaching onto the road. Needless to say that ends up being A LOT of water!
And that was a major part of the problem. As once all that mass of water got to the crossings at Taradale Road and Herrick Street, there were only single, concrete culvert pipes, about one meter in diameter going underneath each road. That massive amount of water didn’t go through those small pipes anywhere near as quickly as it needed to.
Stormwater pipes along the length of the creek adding even more rainwater into it, and tides at the creek’s outlet into the estuary effecting its drainage just exacerbated the flooding upstream.
So, when Napier City Council announced they were going to be increasing the size of these culverts, my main thought was “by how much?”.
It turns out the answer was “LOTS!”
It turns out lots of locals were also interested in the work. About 50 people turned up on a sunny Saturday morning to walk around, and through, the culvert work. I was part of the second group to tour the site with Napier City Council and Fulton Hogan staff talking us through progress.
As we walked through the new culvert sections, I had to get an idea as to their size. I’m a tad over two meters tall (yes, REALLY!). With my arm raised above my head, touching the top of the culvert indicated it’s about three meters high. The culvert is around twice as wide as it is high, so three meters by six meters is significantly larger than the original one-meter diameter pipe!
Photo courtesy of Napier’s Mayor.
You might wonder how we were able to walk through a creek culvert without being waist-deep in water, weeds and inquisitive eels? Well, part of the works has involved damming either side of the culvert, with diversion pipes helping keep at least some of the creek’s flow going.
The bottom of the new culvert is actually below the current creek bed level. There are plans for the creek bed through the culverts to have rocks added and ultimately make the area as natural as possible for the wildlife, which includes eels, ducks, shags, herons and occasionally spoonbills, that live in the creek.
I will be interested to see how the bigger culverts effect the creeks flow.
I would expect the regular depth to possibly drop a bit, given the bigger pipes allowing more water through more regularly. But the added volume currently backed-up on the Kennedy Road side of the Herrick Street culvert flowing through more freely might equalise that out.
There might even possibly be more of a tidal effect from the Ahuriri estuary nearby (there are already, albeit slight, inward and outward tide movements in the creek, along with the occasional school of mullet or similar fish who come for trips up-stream.
Whenever the next significant rain event happens once work is complete I’m confident the creek level won’t get as high as 2020 again. The increased flow rate will be interesting to see, though.
Water Flow vs. Traffic Flow
I do have one concern about the Taradale Road culvert redevelopment, but it isn’t about the construction.
Hawke’s Bay drivers are notoriously BAD. Anyone who has driven on our roads for a while will know that situational awareness, courtesy, and an ability to follow road rules can often be lacking to say the least.
But back to my concern: During the redevelopment of the Taradale Road culvert, hill-bound traffic has had right of way (mainly because it allows Napier’s Fire Brigade, stationed right next to the roadworks, quick access to the city centre). This has included hill-bound traffic crossing to the opposite side of the road while the second half (Kmart / Mitre 10 side) of the culvert was being laid
Meanwhile traffic that usually turns left at the Taradale Road roundabout at the base of the hill to go towards Onekawa and Tamatea has been blocked and had to detour via Georges Drive, Herrick Street and Douglas McLean Ave/Alpers Terrace, or Ford Road between Kmart and Mitre 10.
When the culvert work is finished, and Taradale Road reopens in both directions, I can see this causing some problems, and probably a few accidents.
Because, at the corner of Taradale Road and Alpers Terrace there is a Stop sign and two yellow lines across Alpers Terrace. Not that you would know it from standing at the bus stop in front of the fire station, watching the corner.
Some people stop, but most drivers seem to consider it a “Give Way” at most, or just blatantly ignore it. This has made the corner a site for regular motor vehicle accidents for years.
I fear several months’ construction and accordingly altered traffic flow will only make the frequency of crashes on the corner spike once regular two-way traffic is reinstated.
With no Onekawa-bound traffic crossing their path, vehicles turning left from Alpers Terrace into Taradale Road have not needed the regular awareness of cross-traffic to their right and months of thinking they (‘still’?) don’t need to obey the Stop sign at the corner.
Equally, those currently turning right unencumbered from the fire station side of Taradale Road into Alpers Terrace will likely get a sudden surprise to discover traffic coming towards them once again halfway through their turn.
I outlined these concerns to the Napier City Council comms people at the tour, so it.will be interesting to see what sort of publicity or guidance there will be in.the lead-up to Taradale Road fully reopening once again.
The last thing we want after months of constamt construction closure is months more of sporadic crash-related closures and disruptions!
