The Whau Valley Dam will be off limits to the public for the next six weeks while pine trees are harvested next to the dam.
Work to harvest the 6ha was planned to start in February but was delayed by bad weather. Whangarei District Council owns the land, which is expected to yield 3900 tonnes of wood when harvested.
The harvest is scheduled to start on Monday, but public access to the dam was closed earlier this week as contractors began preparing the site.
A temporary access road and a loading platform for logging equipment and trucks will be constructed close to the dam entrance gate. A second loading platform will be constructed close to the carparking area at the top of the dam.
The 700m boundary fence would be removed and then replaced at the end of the harvest.
WDC commercial property manager Mike Hibbert said the whole operation was heavily weather dependant and therefore the planned five to six week timeframe could vary. The council had taken into consideration the site's proximity to residential property and the main water supply.
"The trees are not in a catchment that runs into the dam, so the water source will not be affected. Even so, we need to minimise the amount of sediment in the environment and we will be using lots of different systems including using hale bales, shredded timber and bark to capture sediment and reduce run off."
Logging usually starts at 7am, but contractors have been instructed to start at 8am and finish by 5pm. The trucks will also be looking to time their exits from the site to avoid the peak traffic times for work and school.
The temporary loading platforms will be removed and the land regrassed once the work is complete. A post-harvest clean-up will also take place to remove any leftover debris.
Mr Hibbert said the logs would be taken to the port and sold into a variety of markets. The tracks in Coronation Reserve would not be affected.
The area will be replanted in native trees that comply with the New Zealand Emissions Trading Scheme.