Land Application

Land application

The Biggest Impact on Your Property

In New Zealand, all wastewater systems discharge to the land via a land application system (LAS). It’s actually the LAS that has the biggest impact on your property.

It’s why at WaterFlow we don’t just focus solely on the treatment system like others do. We consider your vision for your property first and then find the LAS that will achieve this and finally the wastewater treatment system that will match and meet your needs.

Choosing the Right LAS We know choosing the right LAS can be a complexed process to navigate.

This is why we guide you through the process. We suggest you get us involved early on in your project so that we can ensure that the system we design is in line with the vision you have for your property.

Regulations and Requirements Land application systems can be installed above or below ground, but councils do have varying regulations and requirements around this.

Typically slopes of less than 10 degrees have little restriction, slopes of more than 25 degrees can be subject to resource consent.

Our slope calculator can help you work out what slope you have.

We know that these can be overwhelming, but with years of industry expertise, we know our way around these regulations and consents and will be here to share our knowledge and support you, so that’s one thing off your mind!

Plants for Your Disposal Area When installing an irrigation system above ground, it will require covering in mulch and the area planted out.

The best plants for wet areas are those with a high transpiration rate, vigorous growth, and water tolerance. Your options are not limited to native plants but since they are more accessible, they are ideal for huge wet areas.

Standard lawn grass is a proven effective high transpiration plant species in such conditions, as are a large number of other plant species seen in typical domestic gardens.

You can find a list of suggested plants for your disposal area here. Or for more information we recommend you contact your local nursery.

Caring for our Shared Backyard We are stewards committed to helping preserve our environment.

At WaterFlow we will always recommend to you the land application system that meets your requirements and contributes to a cleaner New Zealand.

Land Application Types

Biggest impact on your property

The most common method of discharging wastewater to the ground is through an irrigation or soakage system.

PCDI Irrigation Pressure Compensating Drip Irrigation (PCDI) is a flexible irrigation system that requires higher levels or wastewater treatment.

It is commonly required on heavy clay soils where soakage is limited, and it is important that the treated water is spread evenly.

  • PCDI has small emitters allowing a limited flow, this forces the liquid to distribute across the entire field rather than pooling in one area.
  • Due to the fine emitters, the treatment plant must treat to secondary level and the lines regularly cleaned.
  • The PCDI lines can be of varying lengths and run across contour to a certain degree, giving much more flexibility to the layout and shape of the irrigation area.
  • At the end of the lines are flush taps, that allow the flushing out of any contaminants that might build up over time, it is best done with clean water. At the end of the main feed line is the end flush tap. It is similar to other flush taps, but some systems will have a hose fitting for back flushing properties.
  • If your irrigation is buried, the flush taps will be found under purple flush boxes. These have a purple lid and sit flat to the ground to allow the area to be mowed.

NEED: LINKS TO PDFS: Single Side Manifold, Single Centre Manifold, Dual Manifold

LPED Irrigation The most robust irrigation system for discharging wastewater is the Low-Pressure Effluent Distribution (LPED) irrigation.
  • Lines of equal length are laid 1-1.5m apart (spacing is dependent on council regulations) on a level contour and they can either be covered with mulch or buried in the topsoil.
  • The laterals are fed from a manifold at the head of the field, ensuring an even distribution across the field. The irrigation lines are a 25mm lateral with holes drilled at consistent spacings.
  • At the end of the laterals are flush taps, that allow the flushing out of any contaminants that might build up over time.
  • The size and number of the holes is calculated by our design technicians for each project. Innovative squirt guards developed here at WaterFlow, clip over each hole to stop it spraying into the air.
  • Larger pipe and orifice sizes mean that it isn’t prone to blockage, although in the worst-case scenario it is possible to clear a blockage.
  • LPED takes more care in the design stage, as there are limitations on the individual line lengths and total field sizes. Failure to design it correctly can result in ponding and uneven distribution.

NEED: LINKS TO PDFS: LPED Field Calculator, Typical LED Layout, Squirt Guards

Soakage Systems Soakage systems rely on the earth’s ability to soak up the discharged water, so they are better in ground with a lower clay content. Evapotranspiration can also be utilised, to assist the take up of moisture.

They use higher loading rates than irrigation systems and can reduce your discharge area by up to 50%.

These are the most robust distribution systems, as they aren’t subject to damage from stock or foot traffic. They also use large holes rather that small orifices, meaning there is much less chance of blockage. Of course, along with the benefits, these systems do have a higher cost.

ETS Beds Evapotranspiration Beds (ETS Beds) are a low-pressure irrigation system laid through a soakage bed. This allows you to minimise the size of your land application area.

The beds can be between 0.5 – 3.0m wide and 0.45m deep and are filled with gravel, in which the effluent is discharged using a low-pressure distribution system. The bed is then mounded with soil and plants on top. These help with surface water runoff and the plants assist with transpiration and can be loaded at a much higher rate than irrigation, thus reducing the land application area by up to 50%.

Conventional Soakage Bed These are much the same as an ETS bed. However, they can also be constructed with drilled 100mm PVC and trickle fed from a septic tank.

The top of a soakage bed doesn’t require mounding or planting. It is important to remember that these are only suitable in soils which drain well.

Conventional Soakage Trench Soakage trenches are much the same as soakage beds, however they are no more than 0.5m wide.

There are a few variations to these, such as sand trenches and deep trenches. Conventional soakage trenches are not so commonly used and depend on council regulations as to their use. If you’re unsure, then get in touch with us early on in your project and we can help you.

Raised Mounds Similar in principle to ETS beds, these are built up and constructed above ground rather than being dug in. Their purpose is to minimise the possibility of groundwater contamination.

Raised mounds are ideal if there is an elevated water table or a flood prone area, where it is necessary to lift the height of the discharge.

Boreholes  Deep bore holes are typically 0.6m in diameter and 6.0m deep, the number of holes is determined by a four-hour soakage test. The boreholes have a discharge pipe down the centre and are filled with coarse aggregate.

Since these require resource consent and aren’t a permitted activity under any council in New Zealand, boreholes are only used on small sites with very limited options for discharge.

We're here to help, get in touch with us to Get a Free Site Assessment as early into your project as you can, and we can recommend the best land application system for your site or property.


We’re in 6,000+ backyards around Aotearoa New Zealand

At WaterFlow we work across the country recommending and installing smarter wastewater and sewage systems, for a cleaner New Zealand.

Whether it’s upgrading a water tank or installing a new water system, we always offer bespoke solutions designed to fit your environment and lifestyle. Take a look at our recent projects to be inspired.

Passive Solar Home

Our clients came with the mission of creating their own passive solar home. The NaturalFlow system was an obvious choice, being power-free. We were able to help them achieve their dream on this awesome property.

Off-grid, tiny homes
14 December 2023
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Family Home

The EconoTreat was perfect for this family home. With higher volumes of waste and council requirements of secondary treatment, they needed a system that would provide a consistently high treatment.

14 December 2023
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Packhouse Accomodation

With large seasonal fluctuations, this kiwifruit packing facility needed capacity for peak season staff. A custom designed system by WaterFlow met the requirements for the project, with the capacity to process up to 54,000L per day.

14 December 2023
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Otamatea Marae

Struggling to have enough water to sustain the events, we were asked to upgrade the water tanks and drainage. With an additional four 25000L tanks, they aren’t likely to run out any time soon!

Marae & Light Commercial
14 December 2023
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Rural Oasis

The Naturalflow NF8000 System was used in this piece of paradise. The landscaping gives it a tropical feel, as you step through to the pool for some quality time out.

14 December 2023
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Bahá’í – Henderson

With major upgrades to the building and facilities, the Spiritual Assembly of the Bahai’s was in need of an upgraded wastewater system.

Marae & Light Commercial
01 December 2023
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"Everyone in your team from your sales, design and the delivery guy has been so knowledgeable and fantastic to deal with.

Everyone that has been here for site visits and install have been so easy and a pleasure to deal with. So much so we are choosing you guys to do it all over again with."

Jo - Kaukapakapa February 2023

"Kia ora, I've been dealing with many different aspects of getting a small house built for us on our section for the last couple of years, and it's taken a long time because so many people we have engaged have been slow or unprofessional in their work.

The two people who really stand out as complete contrast to this work for you - both Caleb and Sandra have been nothing but absolute treasures in this process. They have been professional, knowledgeable, helpful, and extremely patient. We could not be happier with their work.

Thank you for employing such excellent staff."

Joey - Waitakere January 2023

"A big thank you for Adam’s efforts today. He braved the rain and very efficiently checked the system, repaired the two leaks and also helped us out with some paper work. You have a good set up.

Thanks again and best wishes to you and the team there."

Tony - Waipapa November 2022

"I have found your entire staff a pleasure to deal with.

Your first contact personnel, sales people, sales support and installation team have been very helpful and courteous; nothing has been a problem they can’t fix."

Frank - Riverhead June 2022

"Thanks for getting Adam out so quickly today.

FYI, he was extremely helpful in explaining the system etc and I really appreciated his approach and advice."

Paul - Waipapa June 2022

"Yesterday while your workers were at 90 Opito Bay Rd the elderly gentleman owner had a fall grazing his knee and appeared to be a little confused. Some how, someone went to the extra caring mile to find a contact to alert his accident to family.

I want to acknowledge this wonderful & heartwarming humanity with a big thank you. Above and beyond great service!"

Chris - Kerikeri May 2022

"Waterflow n.z. supplied and installed the wastewater system on our lifestyle block completing it on the last working day before the Christmas holidays.

We love the system and were very satisfied with the installation and service. They were great to deal with and left us feeling confident in future servicing and maintenance."

Peter - Whananaki March 2022

"We've been really impressed with the service and professionalism from your team - thank you.

Gary also did an excellent job, very tidy, great to communicate with, and happy to accommodate our requests."

Lauren - Waimauku February 2022

"The biggest thanks to you and your team. You have all been an absolute pleasure to work with and would highly recommend at any time to everyone. Thank you all.

We are so stoked with the outcome and can’t wait for the system to get up and running. A massive thanks to Gerald too for taking the time to educate me in all the ins and outs of sewage – all of you were all so helpful and made the process sooo easy."

Rebekah - Kaipara Flats December 2021

"Water Flow has been an absolute pleasure to work with from start to finish.

Everyone has been knowledgeable, friendly and professional. Your contractors are excellent, highly skilled and very professional. Communication has been exceptional

I have no hesitation in using your services for our new house system and would highly recommend your services in the future."

Andrew Chapman - Hakaru September 2021

"Gavin was great during the installation and so far all has gone well so thanks.

The site has been left well-groomed and with minimal mess, which considering the time of year and amount of water around is very much appreciated."

Aaron - Kaiwaka August 2021

"Thank you for making it such a smooth process with excellent communication and even better customer service.

You arrived on time, completed the work to a high standard and caused no issues for us. Thank you must go to you all."

Otamatea Marae April 2021

"We are happy with the installation of our septic system thanks.

The speed from us saying that we were ready for the installation and the job being completed was great. Also the site being left in a nice clean state was exceptional.

Great people all round to deal with. Thank you"

Meghan and Keith - Kaipara October 2020

"Thank you for your services, you have an excellent working crew and you all in the offices there made the whole paperwork and organizing of the job processes so easy for me it was so good to leave it in your hands and not be doing it myself, as I had to with the rest of the stuff I’ve had to do during this time."

Thelma - Ruawai June 2020

"To Whom it May Concern Our Papakainga in Pouto (currently 8 homes on site) had major septic issues and due to Health & Safety reasons the Council was justified in demanding an upgrade.

Natural flow provided an environmentally sustainable system that uses a natural process to treat our wastewater to a very high standard. This was extremely important to us as the Papakainga lies adjacent to the Kaipara Harbour.

To date we have experienced great service and maintenance of the system and the Council is happy too."

Pouto Papakainga – Pouto March 2020

"Thank you very much for the work & installation of your system.

It was a pleasure to see how fast, efficient and what an excellent job they have done, nice and tidy job too, very impressive thanks again, I will enjoy using this system knowing that it's environmentally friendly too."

Victoria - Tinopai July 2020

"Just wanted to add that you guy's have been amazing throughout this process, Gerry has been so great to deal with, himself and the other two guys were super efficient and very tidy completing the job on site and it was done on time even with my dates getting pushed out and not 100% confirmed until about a week out from the house arriving on site it felt like it was no issue to Gerry and he was very accommodating.'

Emily - Hatuma November 2019

"I have to say i am very impressed by your work done given what was the potential. I agree i think its fairly late in the season to worry too much about Grass recovery and if it does need a bt of a help it won’t be until closer to spring anyway, but for now its looking good.

Thanks again. We can touch base later around that. Thanks again, were really impressed by your Company.

I would have absolutely no hesitation in recommending anyone in both the product and your after care support. We really appreciate it!"

Mark - Te Kauwhata June 2019

"I would also like to thank you guys for your exceptional customer service. we have been impressed by the professional attitude by your team.'

Glenn - Ruawai June 2019

"I just wanted to say ‘thank you’ for sending two such lovely, competent men (Hamish & Rangi) to repair our septic waste water field.

They were 100% professional and a real credit to Natural Flow."

Leesa - Whangteau May 2019

"We have been super happy with our new Wormerator. The guys were absolutely awesome on the installation. Jimmy, Terry and Rick were so hardworking, thoughtful and friendly.

They have done an outstanding job. Mary Kay was also very helpful in all our communication."

Jessica - Ngunguru January 2019

"ust a quick note to thank you guys for doing such a great job for us. You made the process very clear from the outset and kept us totally informed along the way.

The drain layers turned up when they said they would, worked in appalling conditions and came back to finish off without a grumble. I wish all our dealings had been so trouble free.

Thanks again to you, Ken, Garry and Terry the drain layers and your team."

Warren - Kumeu September 2018

"Stoked with the work done, the boys on the diggers did an awesome job. Everything was left nice & tidy, super happy!!"

Cullen - Stillwater November 2017


Protecting the Future of Your Property and our Shared Backyard
At WaterFlow we are with you from start to finish – and beyond. Once installation has finished, we are still on hand to provide, maintenance, support and servicing.

Discover ways to maintain your systems in between servicing and how to contact our expert service technicians.


All you need from first inspection to post-install support

For trade professionals, working with WaterFlow means gaining a reliable lifelong partner committed to achieving project success, and a team that values collaboration, precision, and timely execution.

It all starts with your site

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Not sure what will work for you? Let us take a look.

Your site and dispersal field have the biggest say in which system will work best for you. Let our team take a look, either on site or via aerial mapping, and we can help you find a solution that works for you.

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