The intensity of the tropical low generated by this cyclone coinciding with the February spring tides would have had a significant impact on the gravel coast.
Rock revetment on sand and gravel coasts with longshore currents would normally extend to a headland, river mouth or where the beach is in accretion so eventually this structure should end at the Maraetotara River mouth.
For now, another 400m of revetment would protect the caravan park and stop more concrete blocks collapsing on to the beach.
It would be a shame to see this oversight create more 'down-stream' damage and allow this well proven coastal protection get criticised or somehow considered problematic.
Erosion at Clifton and Te Awanga is an act of nature due to a lack of replenishment material collapsing from the cliffs of Cape Kidnappers and directly related to subsidence of between 0.8m and 1.0m during the 1931 Earthquake.
Since the 1960s, this isolated erosion and less frequent severe NE swell events has reduced gravel input to the beach system.
The devastation to baches on the beachfront at Te Awanga to support action against climate change is disingenuous.
This property damage is due to the gradual starvation of replenishment and the resultant correction to the beach alignment.
Several owners of these properties made improvements and installed a variety of concrete seawalls and the 'end effect' created by the northerly drift exacerbated erosion for property to the north.
Unlike both councils who have dismissed my research and opinion, I believe solutions for erosion are simple providing the cause is clearly established.
It's disappointing to find public servants using graphic photos and videos of houses being devastated by this unattended erosion to justify urgent preparation for future erosion and sea inundation due to predicted sea level rise.
It's time to stop the expensive reports and endless meetings and focus on proven solutions for existing erosion that are adaptive to climate change.
Regardless of climate change, hard coastal protection is the only long term option to address ongoing beach erosion from the Tukituki River mouth to Clive.
This erosion will continue unless there is another major event similar to Cyclone Bola.
Over the three years following that significant high rainfall event, 477,000 m3 of gravel entered the coast and provided ample replenishment for northern beaches to the Marine Parade for many years.
In 2012, Hawke's Bay Regional Council coastal experts estimated meagre volumes of gravel at less than 3000 m3 per year (May 2013 - T&T Sediment Assessment p66) were entering the coast via the Tukituki River.
Therefore, coastal sediment plus sand from the Ngaruroro and Tutaekuri rivers being transported north is maintaining a state of accretion between Awatoto and the Port breakwater.
The regional council Coastal Hazard Strategy was advised this section of beach will not be affected by climate change so it will not need any form of hard or soft engineering.
The large stormwater drain below the viewing platform (outlet built at current high tide levels) and the Port breakwater (protruding more than 100m east of the foreshore) are acting as sediment retaining groynes so the growth of these beaches is limited by the eastern extent of the breakwater.
According to experts, these beaches will be resilient to sea level rise and predicted storm surges.
From 1983, the Port built an outer arm off the end of the breakwater to address the 'eddy effect' of north drifting sand entering the Port harbour to maintain use of berths at No 2 wharf.
This structure blocked sand moving via the Marine Parade and created a mound containing 1.5 million m3 of sand which is now stable out to the Inner South Channel.
This extension to the breakwater significantly reduced the amount of sand that filled the shipping channel between maintenance dredging over 20 odd years.
The vast volume of sand moving via the Marine Parade and trapped in the Port's vital shipping channel since it was dredged in 1973 has deprived natural supplies of beach replenishment for the northern Littoral Cell.
The Port and management at both councils are adamant the 1931 Earthquake is the primary cause for Westshore Beach erosion and the contribution by the regularly deepened shipping channel is insignificant.
Larry Dallimore is a Napier city councillor
