About 'Flooding Us'

Flooding Us is a volunteer, community-led initiative formed by residents concerned about flood-risk misrepresentation, unsafe planning decisions, and the financial and safety consequences of flawed flood modelling used by local and regional councils.

We focus on evidence-based advocacy, providing clear, plain-English explanations of technical issues so the public, Councillors, MPs, and government agencies can understand the real flood risks facing our communities.

Our work has centred on exposing major flaws in the flood modelling for the Pinehaven and Silverstream areas of Upper Hutt, advocating for public safety, and calling for transparent, accountable decision-making, particularly regarding the Pinehaven Stream catchment and the proposed large-scale Guildford Timber Company (GTC) development.

With the current Upper Hutt flood-mapping consultation (3 November–12 December 2025), our focus now extends to the wider Upper Hutt area. Notably, the Pinehaven and Silverstream flood maps have been excluded from this consultation.

Current Purpose of This Website

We urge the public to make submissions here … Upper Hutt Flood Hazard Modelling | Have Your Say | Greater Wellington … requesting that:

• the outdated Pinehaven flood maps be included in the consultation; and
• the consultation period be extended, allowing new Councillors and the community sufficient time to understand the issues and make informed submissions.

Flooding Us advocates for accurate, scientifically sound flood models so that homes, families and infrastructure are not put at risk by:

• incorrect flood mapping

• poorly validated flood models

• oversized and costly but ineffective engineering works

• unmanaged stormwater runoff from areas targeted for development

The group advocates for independent, transparent flood modelling reviews to avoid decisions that could worsen flooding for thousands of residents.

Flooding Us documents and challenges:

• withheld technical information
• inaccurate claims used to justify planning decisions
• consultation processes that appear predetermined
• reliance on unverified flood models to advance land rezoning or development

The group seeks full transparency and proper public engagement from Greater Wellington Regional Council (GWRC), Upper Hutt City Council (UHCC), Hutt City Council (HCC), and Wellington Water Ltd (WWL).

Flooding Us highlights multiple issues with the Councils’ Pinehaven flood model, including:

• unrealistic hydrological parameters

• modelling forested hills as if they are already urbanised

• failure to calibrate or verify the model to real events (e.g., 8 Dec 2019 flood)

• misuse of “freeboard” to inflate flood zones

• peer-reviewed expert and community concerns that were ignored or downplayed

The group argues that flawed baseline data masks the flood impacts of Guildford Timber Company’s proposed development and unfairly shifts flood risk and cost onto the public.

Flooding Us supports:

• responsible urban growth

• infrastructure and flood protection that matches real catchment flood behaviour

• development that keeps communities safe

• decisions backed by sound science

They oppose:

• large-scale development without full and proper stormwater management

• land rezoning based on unreliable flood models

• inflated baseline flood models that cheat stormwater neutrality and transfer the problem and cost of stormwater management from developers to ratepayers

• ratepayers funding oversized works that don’t provide promised protection

Flooding Us produces:

• comprehensive reports

• technical appendices

• timelines of council decisions

• Q&A sheets, glossaries, infographics and diagrams

• resident interviews and flood documentation

• submissions to councils, reviews, and public consultations

• clear summaries for councillors, MPs, and media

Our goal is to make complex hydrology, flood modelling and planning issues understandable, so communities can participate meaningfully in decisions that affect them.