OIA26-0250
29 April 2026
Nigel Gray
[FYI request #34279 email]
Dear, Nigel
Thank you for your email of 30 March 2026 requesting information relating to hydrological
cycle and rainfall system assessments. Your request has been considered under the Official
Information Act 1982 (OIA).
You requested the following:
1. Rainfall system and moisture recycling assessments - Al documents, reports,
modelling, internal advice, briefing notes, emails, meeting records, or scientific
assessments held by MPI that relate to:
a. the impact of reforestation or afforestation on regional rainfall, precipitation
patterns, or moisture recycling systems
b. the role of indigenous forests and exotic plantation species in atmospheric
moisture generation, evapotranspiration, or cloud formation processes
c. any consideration of rainfall restoration, hydrological cycle repair, or rain
system resilience in the context of the One Bil ion Trees programme
2. Development of the One Bil ion Trees science priorities - Al documents that informed
the development of the “Science Priorities to Support One Bil ion Trees”, including:
a. any analysis of whether rainfall system or atmospheric hydrology functions
should be included
b. any discussion of the omission of rainfall system impacts
c. any advice received from internal or external experts on moisture recycling,
forest driven rainfall, or atmospheric hydrology
3. Internal and external correspondence - Al internal MPI correspondence (including
emails, memos, Teams/Slack messages, and meeting notes) and all correspondence
with external parties (including NIWA, universities, consultants, and forestry sector
organisations) that discuss:
a. rainfall impacts of reforestation
b. hydrological cycle implications of large scale planting
c. comparative rainfall system effects of indigenous versus exotic forest systems
4. Programme level assessments - Al environmental assessments, risk assessments,
or programme level evaluations that address — or explicitly decline to address — the
rainfall system consequences of the One Bil ion Trees programme.
There is no documentation pertaining to the subjects listed in this request. Our priorities have
been on successful afforestation of carbon sinks in forests and understanding factors
influencing carbon flux within those forests.
Therefore your request is declined under section 18(g)(i) of the OIA
, that the information
requested is not held by the department or venture or Minister of the Crown or organisation
Ministry for Primary Industries
Charles Fergusson Building
38-42 Bowen Street
PO Box 2526
Wellington 6140, New Zealand
mpi.govt.nz
and the person dealing with the request has no grounds for believing that the information is
either held by another department (for itself and for a departmental agency hosted by it or an
interdepartmental executive board serviced by it) or interdepartmental venture or Minister of
the Crown or organisation, or by a local authority
Should you have any concerns with this response, I would encourage you to raise these with
the Ministry for Primary Industries at
[email address]. Alternatively, you
are advised of your right to also raise any concerns with the Office of the Ombudsman.
Contact details are: Office of the Ombudsman, PO Box 10152, Wellington 6143 or at
[email address].
Yours sincerely,
Rebecca Burson
Acting Director, Forestry Insights
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