Mangawhai Estuary Hazard removed

 

 

A large sandbank in the Mangawhai Estuary ski lane has been removed by the dredge Spirit of Mangawhai alleviating what had become a dangerous marine hazard.

The dredge spent the last three months pump-ing sand from the estuary hazard and onto the distal spit.

Mangawhai Har-bour Restoration Society (MHRS) president Trevor Downey said the build-up of sand from the sand trap in the ski lane had prevented boaties from running aground on the sandbank at mid-tide.

The Society owns and operates the Spirit of Mangawhai under a Re-source Consent that li-censes it to maintain the harbour by dredging and depositing sand on the harbour fringes.

“The sand trap could have been very dangerous if we hadn’t removed it,” said Mr Downey.

“We had no idea how large that sand trap had become,” he said.

MHRS has undertak-en dredging operations in the harbour for the past 10 years.

This year the annu-al dredging programme was completed at the end of September.

By choice the Society generally limits dredging

to an approximate three month window, although in the past has dredged outside this period in ar-eas where wildlife is not impacted. Legally it can dredge throughout the year but is careful not to infringe on bird breeding areas.

Mr Downey said the dredge was still in pris-

tine condition but over the summer the Society would need to replace the snorkel. Each summer the dredge undergoes a maintenance programme so it is ready for work dur-ing winter.

This year the diesel cost alone for dredging operations totaled about $7,000. MHRS also pays

dredging operators, mak-ing the dredging pro-gramme a major part of the Society’s budget.

Further areas of sand build-up which were of concern to the Soci-ety were at Bullet Point which is opposite the bot-tom of Heather St, and some build up in sand off Picnic Bay.

“Right now these two areas are not too bad, and we hope that the work we have done in the ski lane will create more water flow and drag the sand away from these two are-as of sand build up,” said Mr Downey.

The Society had con-sidered dredging opera-tions off Picnic Bay, but the tide current in the area meant it would have been extremely difficult, if not impossible, to keep the dredge in position.

“How we remove

sand in those strong cur-rent areas is something we are going to have to work through over the next six months,“ said Mr Downey.

This year the dredge has been operated by John Ganley, an experi-enced dredge operator, and Grant Stewart. Mr Downey paid tribute to both men.

“They worked me-thodically and tireless-ly during some of the worst weather conditions we have seen in recent years,” he said.

“These guys worked seven days a week and would come back some days battered and bruised from the wind and driv-ing rain.”

Note: The completion of dredging operations has meant birdlife on the distal spit will miss out on a feed of worms most days. When the sand was pumped from the harbour and sprayed onto the spit, the birds could be seen eating worms dug up from the estuary floor.