Philippa Stevenson: Dutch students set minds on matter of erosion

COMMENT

A refreshing on-shore breeze has blown on to Waihi Beach, gusting through entrenched positions and cooling a hot spot.

The fresh air blew in from the Netherlands in the form of five hydraulic engineering masters' degree students from Delft University of Technology - Joost van der Lans, Jan Wagner, Ronald van Dijk, Raoul Loeffen and Joost Brugmans.

Last week, the five Delft Abroad Consultants, all 23, presented the result of weeks of study of a controversial erosion problem at Waihi Beach to residents and the Western Bay of Plenty District Council.

Their findings have proved a hit in practical terms and - probably more importantly - by injecting fresh thought into an increasingly acrimonious debate that has raged for the past eight years.

It's all over a delightful stretch of coast with a problem common to many other delightful stretches of coast - a beach that is eroding and bringing the sea ever closer to valuable houses.

In this case it is 2.3km of sand stretching from popular Shaw Rd to The Loop - home to some of Waihi Beach's most expensive real estate.

To everybody who lives in Waihi Beach it is a vexing problem. When the five young Dutchmen wanted to visit New Zealand it was an opportunity to put their newly learned skills into practice, complete essential course work and have a dream holiday at the same time.

For the past eight weeks, based alternately at Waikato University's Coastal Marine Group offices in Hamilton and on site at the beach, the group has wrestled with resource management issues New Zealand style, from central and local government demarcation over coastal hazards to the funding limitations of small Kiwi towns.

The success with which they came to grips with Government policy and community sensitivities while finding some novel solutions for controlling the erosion is a credit to them, and a boon to the beach.

Robyn Ross, spokeswoman for the Waihi Beach Protection Society, said they had brought objectivity and clarity to a debate that had frequently strayed into emotion.

"They had good ideas with a price tag - and they are the ideas that always get more attention. We're now getting to the business end of the debate," she said.

District councillor Nolene De Luca said the price tag on the students' proposals was a bit steep at the moment but their ideas may eventually come in handy.

The council has budgeted $1.43 million to replace a deteriorated seawall to protect the beachfront properties. Designs are expected from consultants Tonkin & Taylor within two weeks. But the seawall is essentially a stopgap measure that won't solve the erosion problem. The Delft students suggest their proposals would deal with the erosion, protect the houses and increase the appeal of the beach.

One option is to "re-nourish" the beach by dredging up sand from a large underwater dune 3km offshore and spreading 500,000 cu m of it along the target 2.3km, maintaining it with an extra 100,000 cu m every five years. The sand would not be put directly on the beach but 300m offshore, from where it would be carried on to the beach by wave action. At the same time groynes, or buffers, would redirect two creeks that erode the beach.

They estimate the initial cost to be $4.8 million and reach $7.4 million over 50 years.

Their second, slightly cheaper option, is to submerge seven 100m to 150m sand-filled tubes in the sea parallel to the shore to act as a breakwater. They would reduce wave energy and allow sand to build up in front of them.

A delighted Robyn Ross said it was good to have some new ideas to put beside those from the council "and the community didn't have to pay for it".

For their part the students were pleased to deal with "real people and real problems, not just theory".

They also had a few thoughts on community consultation.

The council's communication could be clearer to the community, which was not involved early enough in the issue - "usually only when someone has to pay".

And they said it was all very well for district councils to have responsibility for coastal management but they lacked the money and the expertise to do much about it.

Their suggestion, a national integrated coastal zone management committee overseeing the entire coast and liaising between councils.

If the fresh breeze of their ideas should travel beyond Waihi Beach it might do wonderfully well even in windy Wellington.

* Email Philippa Stevenson