How Soon Before Sea Level Rise Makes the Field Totally Unusable?

A Newsroom article has shone a light on the rapidly rising bill to defend a popular playing round in Auckland from coastal flooding.  The issues raised in this article apply equally to Danby Field in Thames, parts of which are regularly flooded from the sea and from a rising water table caused by sea level rise.   How long before Thames High School will have to abandon Danby Field as a usable sports field?  And how soon before the School and the Council have to consider options such as allowing the area to return to a coastal wetland?

Danby Field Thames showing saltwater damage to the surface

Which illustrates that sea level rise impacts are happening now – they are not some far distant problem at the end of the century.

The seawall beside Danby Field has in the past slumped over 1.5m. 

Extract from Ministry of Works letter in 1980’s

Here are some extracts from the Newsroom article.  Bear in mind the Thames Danby Field situation as you read. 

“A report on a flood-prone Auckland cricket ground offers a glimpse of the kinds of decisions that will face people living in other coastal places.

The low-lying bay began flooding regularly from king tides and storm surges in 2009. In 2017, extreme tides caused at least five floods of the boat stand, cricket pitch, bowling club grounds and the road, which is called Maritime Terrace.

Auckland Council’s consultants Morphum Environmental Ltd, have roughly costs the options from doing nothing to raising the whole field by 1m.

It is growing difficult to host cricket games, because the field’s outer boundary is being inundated during king tides, even during fine, summer weather.

To fix the issue, the council, local board and community need to decide how much they want to spend to keep their recreation facilities – if anything. At some point the area won’t be suitable for dry-ground activities, like cricket and bowls.

But the decision is complicated by sea level rise, which threatens to overwhelm some of the cheaper or short-term solutions to the flooding.

While the Auckland Unitary Plan incorporates a total rise of at least 1m over the next 100 years, the long-term prognosis for sea level rise suggests levels could end up rising by as much as 5m over coming centuries, says the report.

The report suggests a variety of options from building bunds on the surrounding land to raising the entire playing field by 1 m.  No estimate was given of the cost for that.

The final option, cost unknown, is full retreat. That involves relocating the sports field, park facilities, carpark, bowling club and dry dock to new locations”