Mangawhai Pakiri Beach

Question 1

what is the sand mined from Pakiri used for

Answer 1

the sand is used for glass and cement

Question 2

what unintentional impacts does the sand mining at Pakiri have on the coastal system

Answer 2

damage to landforms and size of beach as now
1:5 inputs:outputs

Question 3

what % of GDP does this area of New Zealand account for

Answer 3

35% of GDP

Question 4

when did the Mangawhai spit get breached and how big was the breach

Answer 4

in 1978 storms caused a 28 meter breach at the base of the Mangawhai spit

Question 5

how long is Mangawhai-Pakiri coastline and how long has it been operated on

Answer 5

20km
70 years

Question 6

peak extraction rate to current extraction rate in Pakiri

Answer 6

2000 - 150,000 m^3/year
2020 - 75,000 m^3/year

Question 7

what is the issue with increased outputs at Pakiri

Answer 7

Low fluvial sediment budget as sediment is thought to be from offshore

Question 8

what is the estimated retreat by 2100 at Pakiri

Answer 8

35 meters

Question 9

what are the management strategies at Pakiri

Answer 9

dredging of harbour and groyne construction

Question 10

what % of Aucklands sand comes from Pakiri

Answer 10

50%

Question 11

what has happened at Te Arai Point

Answer 11

dunes eroded – sand fills in gaps in beach and less sand to be blown back onto dunes – foredune ridges eroded – seaward facing slopes – loss of vegetation – increased wind erosion

Question 12

what has been the impact on habitats since 1900

Answer 12

loss by 1/3