[this from the Guardian newspaper]

This is the new Act:

Electoral (Lowering Voting Age for Local Elections and Polls) Legislation Bill

General policy statement

The Electoral (Lowering Voting Age for Local Elections and Polls) Legislation Bill (the Bill) is an omnibus Bill introduced under Standing Order 267(1)(a). That Standing Order provides that an omnibus Bill to amend more than 1 Act may be introduced if the amendments deal with an interrelated topic that can be regarded as implementing a single broad policy. The single broad policy implemented by the amendments in this Bill is to reduce the voting age in local elections and polls from 18 to 16 years of age.

The Bill amends the Local Electoral Act 2001 so that persons aged 16 or 17 years are eligible to vote in local elections and polls; it does not change the voting age for parliamentary elections. The Bill establishes a new category of electors, named youth electors, and provides for 16-year-olds and 17-year-olds to be registered on a youth electoral roll.

However, although it lowers the voting age to 16 years for local elections and polls, the Bill does not change the age for—

·         being elected or appointed as a member of an alcohol licensing trust or trustee of a community trust:

·         voting in the election of members of an alcohol licensing trust:

·         voting in the election of trustees of a community trust:

·         serving as a juror.

The relevant age for those activities remains 18 years.

from Wikipedia:

“In New Zealand a person is considered a child or “minor” until the age of 20. On reaching this “age of majority” the person is no longer a child in the eyes of the law, and has all the rights and obligations of an adult.^[2] There are laws to protect young people from harm that they may be subject to due to their lack of maturity. Some legal age restrictions are lifted below the age of majority, trusting that a child of a certain age is equipped to deal with the potential harm.^[3]For example, 16-year-olds may leave school, and 18-year-olds may buy alcohol.”

…and of course vote at 18 with the NZ voting age having been progressively reduced from 21 over the last few decades.

I am old enough to have seen our 8 children grow up and become variously politically aware, and my experience of this combined with information as above strongly suggests to me that voting by most teenagers is unlikely to be well-informed and that younger people are more likely to vote responding to media or peer pressure, not having had enough years/experience to work out what government is about and what is in in societies’ best interests.
There are exceptions of course, but voting age Laws have.to draw a line somewhere.