Category Archives: Stormwater Drainage Systems

What is a Cesspit NZ?

A cesspit or catchpit is a drainage system used primarily in stormwater management. Whether it is sewerage or stormwater, a cesspit is designed to prevent blockages and water contamination in a drainage system. A cesspit is a camber that allows debris and sediments to settle to the bottom of a pit. For this reason it is advisable to regularly maintain your cesspit by emptying and cleaning at least once a year.

Why do you need a cesspit?

A cesspit is typically found upstream of a drainage system. This way the cesspit can collect all debris before it enters public or private stormwater pipes.

Cesspits are most commonly found in gardens, driveways or roadways. These environments typically collect large quantities of debris and sediment which if allowed through would cause blockages in a public drainage system. A blockage could cause flooding, water to return back up a pipe or worse damage property. Therefore a cesspit is vital when managing surface water in any of these environments.

By law all channels and subsoil drainage must flow into a cesspit to ensure no debris can flow into the private or public stormwater lines. For example, a driveway channel may be a vector for debris to collect, and so all water must be filtered before it can be discharged into the stormwater line.

How does a cesspit / catchpit work

Basically, a cesspit works by providing a sump where sediment and debris can fall and collect. Water overflows at the top level of the cesspit leaving debris behind at the bottom of the pit. The clean water then exits through the outlet pipe, which sits just lower than the inlet pipe.

To protect the outlet pipe against potential floating debris, a baffle can be fitted to the outlet. This can help filter leaves and twigs, stopping them from entering the pipe.

Because silt, sediment and debris build up in the sump of the cesspit, regular maintenance and cleaning of the cesspit is required. Typically the average cesspit should be cleared out annually to prevent a build up of debris. Such a build up could cause the cesspit to become ineffective, increasing the likelihood of damage from unmanageable water.

Types of cesspits

The most common form of catchpit is a roadside catchpit. Catchpits can be found intermittently alongside Auckland roads. What is unique about these types of catchpits is their design. Roadside cesspit openings must not allow objects greater than 100mm in dimension to pass through. Openings must also be small enough to prevent sizable debris from entering the system that may cause damage. These cesspits are typically larger than ones found on residential property. Under New Zealand building code these cesspits are known as a type 2 surface water sump.

A type 1 cesspit is no larger than an office paper bin. These cesspits are commonly used in residential applications such as in a driveway or garden.

There are many different names for a cesspit, such as:

  • Catchpit
  • Bubble up chamber
  • Receiving chambers
  • wet chambers
  • Dry chambers

Regardless of the name, the principles are the same. Incoming water is filtered to remove contaminants before entering a larger drainage system. This now clean water can then be confidently reused, recycled, or safely discharged into our oceans or environment.

Cesspits come in a variety of materials. The physical sump is typically made of:

  • Concrete
  • Polyethylene plastic

The top grate of a cesspit is typically made of iron. Iron grates are extremely durable and heavy. This prevents the grate from blowing away in strong weather.

With the increasing popularity of bicycle lanes, a newly designed cesspit finish is becoming more common. This new design is a flat stainless steel grate. Unlike the normal curved iron grate, this cesspit finish is designed to prevent accidents on bikes and scooters. More traditional curved grates can act like a pothole, dismounting commuters off their bike.

Maintenance

Because a cesspit is a static installation designed to filter stormwater it can quickly become full. If Debris and sediment pile up it will cause a blockage, damage and even flooding. Therefore it is necessary to regularly maintain cesspits by clearing excess waste. Ideally this should be done yearly.

Every homeowner should be concerned whether their cesspit is functional or not. One quick test you can do at home is to look down into your cesspit. If you cannot see an outlet pipe then it most likely means your cesspit is overflowing or blocked.

We at Drainage NZ offer our own regular maintenance service. Book with us and receive annual maintenance on your cesspit. We’ll turn up at the same time every year to empty and clean your cesspit with no fuss and at a competitive price.

Give us a call on 0800 372 465 or contact us online to organise maintenance on your cesspit.

Everything You Need to Know About Soakholes

In New Zealand a common method of managing rain water is Soak Holes. In the following information we will be focusing on the city of Auckland which is the most populated and quickest growing region in New Zealand.

In Auckland managing rain or so called “Stormwater” correctly is critical for the cities growth and infrastructure. Auckland Council is constantly challenged by the ever changing weather patterns and population growth. As the population grows so must the public stormwater system, the problem councils have is that the population is:

  1. Outgrowing the public stormwater system
  2. The public Stormwater system can’t grow quick enough to keep up with the demand. This is a costly task that only can only be done during certain times of the year and only as it’s needed. As such, councils are always behind on growing the city’s public infrastructure.

Several years ago, council engineers came up with a quick fix that would help slow down the effects of population growth and the introduction of more water being collected from new roofs that would discharge into the public system.

Design regulations for new builds and subdivisions now included the requirement and/or option to;

  • Allow a property to manage its own stormwater as much as much possibly practical by means of retention tanks, detention tanks (regulated overflow allowing the public system to keep up when there is a high demand) and soak holes.

In section, we will be focusing on the different types of soak holes and how they can help property owners manage rain water from roofs and surfaces successfully. 

Three Different Types of Soak Holes in Auckland

Residential Soak holes

In the early days many areas around Auckland did not have a public storm water system to connect onto. If you had a public connection, you were considered very lucky! Year later in 2020, some areas still don’t offer public a infrastructure. Many homes, especially those built in the 60’s and 70’s continue to manage their roof and surface water within the boundary. This is typically done by means of an onsite ‘Soakhole”.

As drainlayers when we ask for a LIM to identify what

Onehunga Soakholes

Its all about ground percolation and enabling a site or home to manage its own roof and/or surface water within the site itself. What better way is there than allowing nature to do its own thing?   The concept of the Onehunga soakhole does exactly that. (Speak to Drainage NZ about Soakhole drilling, engineering and design.

A GEOTECH drilling rig is arrange to drill down into the volcanic bedrock where a pipe riser is inserted to enable water to overflow as far down as applicable design stipulates. At that point, water will disburse naturally underground. Geotechnical drilling services are available)

As you can see in the design below, the soakhole does have a safety mechanism in case the drilled bedrock hole blocks or should the incoming water exceed the soakhole capacity. This is the overflow point shown as the entry head.

At this point water may overflow into the public system or external soakage trench as shown below.

Trench Field Soakholes

When rock is not available the GEOtechnical engineer may explore the option to discharge stormwater into a scoria layer underground if the site is suitable. The principal is simple. If found scoria layers can act as a disbursement field by allowing water to travel downstream across a whole suburb below the ground, naturally finding a route to the ocean. Because percolation is limited.

Design Notes may Include:

ADDITIONAL SOAKAGE PIT NOTES:

  1. THE CONTRACTOR SHALL TAKE NOTE OF HOLD POINTS ON THE DRAWINGS AND FOLLOW INSTRUCTIONS AS NOTED AND ARRANGE FOR THE APPROPRIATE ENGINEERING REPRESENTATIVE TO BE PRESENT WHERE APPLICABLE AND/OR PASS ON TESTING INFORMATION AS REQUIRED PRIOR TO PROCEEDING WITH FURTHER WORKS
  1. HOLD POINT – THE CONTRACTOR SHALL CARRY OUT SOAKAGE TESTING IN ACCORDANCE WITH THE AUCKLAND SOAKAGE DESIGN MANUAL AT THE PROPOSED SOAKAGE PIT LOCATION WITH THE ENGINEER IN ATTENDANCE. FINAL SOAKAGE PIT DEPTH AND DIMENSIONS TO BE CONFIRMED BY THE ENGINEER PRIOR TO SOAKAGE PIT CONSTRUCTION.
  1. HOLD POINT – THE BASE OF THE SOAKAGE PIT SHALL BE INSPECTED BY THE GEOTECHNICAL ENGINEER FOR APPROVAL, THE BASE SHALL BE 500mm INTO THE BASE OF THE INSITU FREE DRAINING GRAVEL / SCORIA LAYER. DEPTHS SHOWN INDICATIVE BASED ON GEOTECHNICAL INVESTIGATION.
  1. INLET CONNECTIONS INTO MANHOLES TO COMPLY WITH COUNCIL STANDARDS
  2. CONCRETE DRIVEWAY SLAB TO EXTEND A MINIMUM OF 500mm OVER THE ROCKFILL FOOTPRINT ON ALL SIDES
  1. GEOTEXTILE TO BE BIDIM A29 OR APPROVED EQUIVALENT AND SHALL EXTEND DOWN TO GRAVEL / SCORIA LAYER ON ALL SIDES, BRING GEOTEXTILE 500mm UP SIDE OF MANHOLE RISER AND TIE OFF WITH DENSO TAPE. (HOLD POINT – INSPECTION PRIOR TO BACKFILL)

For more detailed information about soakholes and soakhole regulation, please download the following guide called Auckland Soakhole Design Manual.

The purpose of this Manual is to provide guidance in the design of stormwater soakage devices for residential and commercial properties in soakage areas of Auckland  City.    Soakage  areas  have  limited  stormwater  reticulation,  and  are  primarily located in parts of Ellerslie, Penrose, Onehunga, Mt Eden, Epsom, Mt Roskill  and  Mt  Albert.    Public  soakage  devices  are  provided  for  runoff  from  roadways  in  these  areas,  but  individual  property  owners  must  construct  and  maintain  their  own  soakage  devices  for  runoff  from  private  properties.    The  soakage  devices  allow  stormwater  to  percolate  into  the  ground,  and  generally  consist of either boreholes into fractured rock or large holes filled with scoria.  

Can I make my own Soakhole?

The building code does allow a certain extent of “Garden Drainage” without involving a specialist, designer or even a registered drainlayer. We highly recommend you familiarise yourself with the rules before you attempt a DIY. Getting wrong could cause severe your or others property.

The quick answer to the question above is no. Soakhole need to be designed based on a series of things, including:

  1. Location (certain criteria needs to be met)
  2. Incoming water capacity
  3. Geotech conditions
  4. Size and depth
  5. Environmental effects.

The law is a more flexible around existing soakholes that need repair or redrilling. A repair may bypass all the consent and engineering requirements.

If you need your soakhole repaired, moved or removed please speak to our drainage engineers that will be able to help you find a solution that suits your budget and site. 

 

Not only should clients be aware of what the engineering notes are but so should the contractor to ensure a realistic scope is covered which will allow the client to budget the project accordingly.

Some notes may include:

  1. THE CONTRACTOR SHALL LOCATE ALL EXISTING SERVICES WITHIN THE VICINITY OF THE PROJECT SCOPE OF WORKS AREA PRIOR TO THE COMMENCEMENT OF CONSTRUCTION AND CONFIRM EXISTING LEVELS AND ALIGNMENTS.
  2. THESE NOTES SHALL BE READ IN CONJUNCTION WITH THE NOTES ON DRAWING C001.
  3. ALL WORKS AND MATERIALS TO COMPLY WITH AUCKLAND COUNCIL STANDARDS AND WATERCARE STANDARDS. ANY AMBIGUITY BETWEEN THESE DRAWINGS AND COUNCIL STANDARDS SHALL BE REFERRED TO THE ENGINEER FOR CLARIFICATION.
  4. FOR PIPE BEDDING DETAILS, REFER TO STANDARD DETAIL SHEETS UNLESS OTHERWISE NOTED.
  5. WASTEWATER PIPES SHALL BE 150mm dia. PVC SN16 UNLESS NOTED OTHERWISE. (LOT CONNECTIONS SHALL BE 100mm AS PER WATERCARE STANDARDS). NOTES ON THE DRAWINGS SHALL TAKE PRECEDENCE, REFER DISCREPANCIES TO THE ENGINEER FOR CLARIFICATION.
  6. ALL PRIVATE DRAINAGE TO BE CONSTRUCTED IN ACCORDANCE WITH THE APPROVED CONSENTS.
  7. BACKFILL MATERIAL SHALL BE FREE FROM ORGANIC MATERIAL.
  8. ALL PIPE CROSSINGS UNDER ROADS AND DRIVEWAYS TO BE HARDFILL BACKFILLED.
  9. ALL MANHOLES ARE TO BE 1050mm DIA UNLESS NOTED OTHERWISE.
  10. ALL SW AND WW 100mm DIA. LOT CONNECTIONS (RAMPED RISERS) SHALL BE EXTENDED INTO THE FUTURE LOT BOUNDARY AND BE CAPPED AT THE LEVELS SHOWN IN THE DRAWINGS, BELOW THE FINISHED GROUND SURFACE. THE CONTRACTOR SHALL PROVIDE AN AS-BUILT SURVEY OF NEWLY INSTALLED CONNECTIONS UPON COMPLETION OF THE WORKS.
  11. IT IS THE CONTRACTORS RESPONSIBILITY TO PEG OUT MANHOLES AND CHECK FINISHED EARTHWORKS LEVELS (MH LID LEVELS) PRIOR TO ORDERING MANHOLES. DISCREPANCIES SHALL BE REFERRED TO THE ENGINEER FOR REVIEW.
  12. PIPE GRADES SHOWN ON THE DRAINAGE LONG-SECTIONS ARE CALCULATED FROM MANHOLE CENTRE TO MANHOLE CENTRE.

Subsoil Solutions For Aucklanders

Since the deluge in 2017, Auckland’s problem with its ageing stormwater drainage pipes came to light. The city’s population growth, coupled with the rise of multi-unit blocks of flats, is putting too much strain on stormwater facilities.

While the Council is already building a multi-million dollar central interceptor to address Auckland’s water woes, many can be done on the private property owners’ part to help the situation. This includes improving their home’s drainage system to minimise runoff to the streets and prevent debris from funnelling into stormwater inlets. Silt and debris blockage was one of the major contributing factors to the massive flooding and damage in New Lynn during the storm.

Installing structures such as subsoil drainage can help to maintain flow conveyance and remove litter and excess sediments that block hotspot inlets during heavy rainfall events.

The problem with old pipes and clay

About 16,000 households or 2 per cent of Auckland’s wastewater network use combined stormwater and sewage pipes. Many of the pipes in older parts of the isthmus were installed a century ago and have not been replaced or “separated.” In heavy downpour, stormwater can easily overload the pipes and backflow into the sewage system.

The stormwater dilutes the wastewater. And when it overflows on private property, it does not only cause a smelly problem but also poses a bigger issue from a public safety perspective. This usually happens on parts of the network that weren’t separated. In some areas, like Hauraki Gulf Islands, there is no formal stormwater system and natural land drainage isn’t sufficient to deal with stormwater.

The problem is exacerbated by Auckland’s clay-dense soils formed under a warm and moist climate. Clay accumulations are particularly high in western suburbs and the inner city areas have soils.

Clay particles accumulate in the layer of the earth below the surface soil, hence called the subsoil. This layer is made up primarily of minerals and leached compounds, and lacks most of the organic elements and the rich soil fauna and flora found in the top soil. Clay has low-porosity and impedes the land’s natural ability to absorb and drain away stormwater.

So when the rain pours, stormwater tends to pond on low-lying areas around homes or run off to the roads, overloading the public wastewater infrastructure. If the flooding reaches the foundation of a house, it can compromise its structural integrity and safety.

This video shows the usual drainage problems that Aucklanders are facing.

What can be done?

The Auckland Council is in charge of stormwater management, but property owners are responsible for maintaining private stormwater assets that run to their property. These private stormwater assets include drains, catchpits, grates, pipes, roof gutters, rain gardens, permeable paving, ponds and soakage pits.

Soak hole repairs and inspections

Stormwater is typically directed to a soak hole rather than led directly to the stormwater network. In areas with no stormwater reticulation facilities, soak holes allow water to percolate to the ground.

Soak holes are basically manholes with boreholes ranging from 5 to 20 metres deep. Over time, soak holes get blocked by the silt, vegetation and litter they trap, and this can cause flooding. These devices require annual cleaning and maintenance, which can include flushing the bores, disposing the waste properly, and checking the inlet pipes.

Soak hole inspections may also be done at any time to ensure the device is functioning as it should and complies with the required health and safety standards.

Subsoil drainage

If your existing stormwater assets are not sufficient, consider incorporating a subsoil drainage system. It can be as simple as digging a trench and filling it with gravel or rock (called a French drain or weeping tile). Modern subsoil drainage uses a specialised perforated pipe covered with geotextile material, which is laid around the foundation or in low-lying areas within the property.

As well as minimising flood risk, installing an effective drainage system can give your property’s market value a boost. In fact, part of the process of property valuation is a thorough inspection from little things such as materials quality and efficiency wiring and plumbing, to general details like the location, the lot and the house itself.

Nobody wants to buy a house that gets flooded every time it rains. So things like upgrading old plumbing fixtures or installing an efficient drainage system are good investments with greater potential reward. Even if you don’t plan to sell, these projects can increase your quality of life and protect your home from costly water damage.

 

Hiring qualified and experienced drainlayers

Below are some of the important benefits of hiring an authorised drainlayer for the job:

  • Compliance. Drainlaying is generally a restricted work because it involves sanitary fixtures that concern public heath safety. There are also minimum requirements, specifications and standards to keep in mind when building subsoil drainage, especially for subdivision construction. For instance, the subsoil drainage must have a cesspit or holding pit before overflowing into an approved point of discharge. The pipes must also be laid deep enough into the subsoil, otherwise it will simply drain away the surface water and flooding will persist.
  • Real value for money. The right people will provide the right solution for your property. You get quality results that prevent expensive problems from recurring.
  • Professional insurance reports. A standard home insurance typically includes water damage cover. If you want to make a claim due to sewer backup, overflow and discharge, or flood, a licensed drainlayer can provide you with a detailed and professional insurance report to serve as proof. If you are taking out an insurance policy, a professionally written report for your new drainage system will increase your chances of getting coverage for drainage emergencies.

To learn more about subsoil drainage solutions in Auckland, talk to us.

Stormwater Galv Kerb Outlet Installation

What is a kerb outlet? They are essential parts of drainage systems which serve to remove the excess water from your property by directing it to the kerb on the street, which will then flow into the stormwater system.

Firstly, kerb has two spellings, also being written as curb. “Curb” is the American spelling of the word, where as “kerb” is the correct English standard as has been used since the mid 17th century. Since in New Zealand we use the English standard, we will go with the spelling “kerb”.

Kerb outlets can be used in conjunction with driveway channels, gutters and other types of water removal drainage systems.

We just completed a job for a customer which involved installing a kerb outlet for their stormwater drainage system.

For this job, we had to remove part of the footpath as well as some ground from their property in order to run the piping for the outlet. Once the ground was removed, we could lay down the pipe which was 100mm diameter uPVC in this case.

In this system the kerb outlet was used in conjunction with a 5,500L stormwater above ground detention tank. The outlet was connected to the gutter drain as a means of escape for the stormwater.

Once the pipes were laid, we reinstated the concrete on the foot path and to the neighbouring property that had to be removed. The road and driveway were then cleaned up from all the left overs of working there.

Why would you need to replace a kerb outlet?
Kerb outlets are crucial part of stormwater drainage systems that ensure that water being drained can be removed from the property onto the road, where it can then drain into the main drainage system. If your kerb outlet is blocked or damaged, you could find yourself with a flood in your yard, which could even cause damage to your home.

Do you need a kerb outlet for your drainage system? Contact us today to discuss your drainage needs.

Auckland city council is pushing for more detention tanks

So for starters, what is a retention or a detention tank?

Here is a clear definition from Auckland city council.

Detention tank: Detention tanks work by temporarily storing stormwater runoff during a rainfall event and then slowly releases the water into the public stormwater system. These can be located either above or below ground.

Retention tank (Water Harvesting) : A retention tank is used to permanently hold rainwater, which can then be reused for hose taps, toilet use and laundry purposes. Also known as a single purpose rain tank.

Dual purpose tank: Dual purpose tank both retain and detain rainwater. The bottom third of the tank is used to store rainwater permanently (retains) for non-drinking water supply and the upper two thirds of the tank temporarily holds (detains) rainwater and slowly releases it until it reaches the retaining level.

Water supply rain tank: These tanks store rainwater collected from roof areas and provide the main water supply to a household, this includes drinking water. This practice note does not address potable water supply requirements; for further information refer to Clause G12 of the NZ Building Code, which can be found at www.mbie.govt.nz.

Why are detention tanks desired by Auckland city council?

Auckland is growing! As such, its infrastructure must also grow to keep up with the demand, this includes its public sewer and storm water systems into which all properties discharge. Keeping up with this growth could cost tax payers Billions of dollars.

1000’s of new homes are being built with even more homes being extended adding hundreds of thousands of square meters of roof surface collecting additional rain water.

All this water needs to somehow be managed , if not, our public storm water systems will get overwhelmed affecting our public sewer lines and that is something no one wants for obvious reasons. So Auckland city council have come up with a solution that will slow down this infrastructure growth.

The solution was to simply make the managing of this additional rainwater the homeowners problem by introducing detention tanks. The surface area of the roof will determine the size of the detention tank. Rule of thumb is that 1 square meter or roof surface area will equal to 100 liters of detained water (this can change depending on council or conditions).

Detention tanks are designed to take the first load of rain, then with a controlled outlet slowly release the water back into the public storm water system. The size of the controlled outlet will be specified in your consent application.

The controlled discharge will allow the public storm water system to cope with the initial downpour, at some point the tank may completely fill up because the controlled outlet may not keep up with ongoing downpour. At this point in time the tanks will automatically overflow directly into public system. In theory, this should only happen every 100 years :).

In the images below you can see underground detention tanks have been installed (no pump). Having them underground is a great way to hide them. These specific models are very handy because they are only 1 meter deep allowing us in most cases to find a gravity solution rather than having to use a pump.

Drainage NZ can advise on many variations of retention and detention setups. This includes commercial and residential solutions. Simply give us a call if you have any questions.

My next article will discuss a maintenance schedule council urges home owners should maintain.

underground_retention_tanks
retention_chamber_overflowunder_ground_5000L
retention_tanks_and_chamberoverflow_relief_gully

Stormwater Drainage, Why So Crucial

stormwater_draiange_why_so_crucial

Has your property developed a new swimming pool after that last storm or heavy downpour? I wouldn’t try swimming in it though, floodwaters are usually filled with contaminants and pollution from the water picking up things such as trash, oil, fertilisers and what ever else it has swept over before gathering into your new pool.  Just imagine what could be floating around in there contaminating your home and waterways. This is why proper stormwater drainage is crucial to keeping your home and your surrounding environment safe.  If not installed properly it can also become home to mosquitos who will use this wonderful water source as a breeding ground, which is no fun unless you’re a fan of these little bloodsuckers.  A properly installed stormwater drainage system will be strategically placed to ensure your home is drained properly, so you will no longer have unwelcome “swimming pools” coming up on your property every time it rains.

Not having a stormwater drain or having an improper stormwater drainage system that is not operating properly can also cause damage to your house. Water pooling around the base of your house can weaken the structure and shift soil causing cracks in walls and foundations. The shifting foundation can stop doors and windows from sealing properly causing home dampness and mould. We all know a damp house will cause a host of physical illnesses such as respiratory problems. Also you have the cost of running a dehumidifier to try dry your home, heaters to try keep your home warm, the list goes on. So for your health, safety, and your bank account having a stormwater drain installed properly is a must.

In Auckland,  drain layers are required to have additional certifications to work on stormwater systems. Drainage NZ has these certifications along with 20 years experience. Our work is guaranteed. So call us now, we will take care of everything with one call so you don’t have to call around companies for different reasons and for different equipment for different jobs and areas.

Stormwater Drain Solutions By Drainage NZ

Stormwater drainage is an intergral part of any property and is crucial to prevent damage and long term issues from occurring. Drainage NZ can help you to find the stormwater drainage solution you need for your property.stormwater_drains

What can we help you with? Drainage NZ can assist you in the following areas of stormwater drainage:

  • Soak holes
  • Charged stormwater systems
  • Rain and water tanks
  • Stormwater treatment systems
  • Surface water management
  • Pumping solutions and chambers
  • And more

Drainage NZ have been involved in many stormwater drainage projects in Auckland including many council, construction and commercial projects. However, despite our extensive portfolio, no job is too small! We can help you with all residential stormwater no matter what size the job is.

We will apply our expertise to your job to ensure that you have the best possible stormwater solution for your property. To talk to us about your plans, simply call us on 0800 372 465 or visit our residential stormwater drain solutions page.

We Provide Commercial Stormwater Solutions

commercial_stormwater_drainage_systemsCommercial stormwater systems are highly sensitive systems that require a lot of planning, engineering and calculations to ensure that systems are correctly installed and operate as they should. Incorrectly installed commercial stormwater can cause considerable damage.

Drainage NZ are specialists in the commercial drainage field, being in the business for over 20 years experience. We have been involved in a number of commercial stormwater installations and repairs jobs in Auckland, providing the solutions needed for various businesses and commercial properties.

Stormwater drains are important both during construction and afterwards. During contruction, stormwater drainage is needed to keep water clear from the work space allowing work to be done. It is often used around foundations, retaining walls, footpaths and driveways. However, there are various regulations that need to be met with stormwater drainage. Stormwater catchment applications must be managed and discharged to approved points of outfall. These points include natural streams, public stormwater connections, soak holes, detention tanks and pumped solutions. In New Zealand all subsoil drainage must be treated before discharged into a public system.

If you are needing to setup or construction a stormwater drainage system, consult us today for the assistance you need to get it done.