The relevant clause is section 14, which creates two special withholding grounds under LGOIMA:
Section 7(2) of the Local Government Official Information and Meetings Act 1987 must be read as if the following paragraphs were added:
"(k) avoid serious offence to tikanga of any iwi or hapū represented by a tāngata whenua appointer as defined in section 4 of the Hawke's Bay Regional Planning Committee Act 2014; or
"(l) avoid the disclosure of the location of wāhi tapu of significant interest to any iwi or hapū represented by a tāngata whenua appointer as defined in section 4 of the Hawke's Bay Regional Planning Committee Act 2014."
This isn't as bad as it looks. Section 7(2)(ba) of LGOIMA already allows information to be withheld on these grounds, but only in the case of applications for resource consents, water conservation orders, or heritage orders. The Law Commission in its 2012 review of the OIA noted that there was a real question over whether that withholding ground was too narrow, and recommended the creation of a working party to investigate. I'm not sure whether the government actually did that, but applying it to the slightly broader question of the consideration of RMA planning documents seems to protect the same interests and doesn't seem too harmful. And because it is non-conclusive, it can always be trumped by the public interest in any case. It may also prove to be a useful experiment to determine whether such a withholding ground is acceptable on a national level.