So far we have calculators for:

• Centre Pivots
• Linear Moves
• Travelling Irrigation
• Solid Set Irrigation
• In-depth Pressure & Energy Analysis

We sent Dan off to keep working on calculators for:

• Multiple Spraylines
• Drip/Micro Irrigation
• a few other ideas!
• and we haven’t seen him for a while

These calculators are based on the 2005 Irrigation Code of Practice for System Evaluation. Its methods have been very well tested over the years and we a proud to have been involved from the start.

The calculators do not store any of your data. The calculations are done in the webpage on your computer and are deleted when you refresh or close the page. That means only you have your data, but if you want to redo things, you’ll have to start again.

Please give us feedback. We are thinking of adapting the Fertiliser Application calculator to this format as well if we get good reviews. And if people want to save their work, we can look into that too.

We think it is important that our LandWISE membership is up to date on regulations and are pleased to include this post on our website and in our newsletter. Many farm dams are excluded from the new regulations, but there are many that are covered. Farmers sometimes make big ponds, and we are aware of a few “home-builds” that were actually large dams with significant safety significance! Have a look and check your backyard (and the regulations) if you think you might be included.

Dam Safety Regulations are in force

The Building (Dam Safety) Regulations 2022 commenced on 13 May 2024.

The regulations have been made to improve the resilience and maintenance of Aotearoa New Zealand’s dams, protecting people, property and the environment from the potential impacts of dam failures.

Only classifiable dams are impacted by the regulations. Dams are classifiable if they are 4 or more metres in height and store 20,000 or more cubic metres volume of water, or other fluid.

Background to the Regulations
The Regulations were made by the Government in May 2022 and provide a nationally consistent approach to dam safety. Having a dam safety framework brings Aotearoa New Zealand in line with most other countries in the Organisation for Economic Co-operation and Development (OECD).

Since May 2022, the Ministry of Business, Innovation and Employment (MBIE) has been working with industry groups and regional authorities to ensure dam owners are aware of the Regulations and provide them with information and resources to support them to meet their responsibilities when the Regulations came into effect.

What do the Regulations mean for you?
If you are the owner of a water retention structure, firstly you need to determine if your structure meets the definition of a classifiable dam (that is, if it meets the height and volume thresholds).

• If you determine that your dam is classifiable, you will then need to determine your dam’s potential impact classification (PIC). If you do not have a classifiable dam, no further action is required under these Regulations.
• Once the PIC has been determined, you will need to then have the PIC audited and certified by a Recognised Engineer, who will work with the dam owner to complete a dam classification certificate.
• Dam classification certificates need to be submitted to the relevant regional authority.
• Owners of dams with a medium or high PIC have further actions they need to take.
• The only additional requirement for owners of dams with a low PIC is to review their dam’s PIC within five years of the regional authority approving it.
• If you own a dam and fail to meet your responsibilities under the law (the Building Act 2004 Regulations), then you may be liable for a fine.

Resources to help you
You can read more about the definitions, regulations, and find resources to support you, on MBIE’s Building Performance website: www.building.govt.nz/managing-buildings/dam-safety/

Included in these resources is the Measuring and calculating the height and volume of agricultural dams resource. This is designed to help horticultural or agricultural dam owners calculate the volume of their dam and understand if they are impacted by the Regulations.

MBIE has also published another resource, the Potential Impact Classification checklist, which is a checklist to support dam owners to identify and collate information for a PIC assessment.