FAQ

GENERAL +

What is Stormwater? +

Stormwater is rainfall (water from a storm event) that makes contact with a surface ie ground and/or roof.

Stormwater can;

  • Soak into the ground (Infiltration)
  • Be held on a surface and evaporate (Evaporation)
  • Flow across surfaces (Runoff) and discharge to pipes, streams and ultimately the sea 

What is Stormwater Management? +

Stormwater management is the act of managing stormwater runoff from developed sites to protect human and ecological values and prevent adverse impacts on the environment.

There is two main Stormwater management categories;

Quantity management involves limiting the disruption of the natural hydrology by;

  • reducing the impervious land cover
  • controlling the peak outflow discharge ie storing stormwater onsite and releasing it at a reduced flow rate (detention)
  • soaking it into the ground (infiltration)
  • retaining it onsite for water re-use (retention).

Quality management involves limiting the disruption and pollution of natural water bodies by;

  • Preventing contaminants entering the stormwater network
  • Reducing onsite sediment generating activities
  • Treatment and removal of contaminants

 

 

Do Stormwater360 New Zealand provide an installation service for their products? +

Unfortunately No. We recommend engaging an external contractor (typically a registered drainlayer) for installation of our products.

MAINTENANCE +

What is maintenance? +

Maintenance involves the care, upkeep and repair of stormwater management devices/assets to ensure they are operating efficiently and safely.

There is two main types of maintenance work;

  • Preventative maintenance includes regularly scheduled inspections and activities to keep the device in good working order and prevent issues from arising. ie Similar to a regular car service
  • Corrective maintenance includes emergency or non-routine activities requiring reactive action to be implemented to repair the device. ie similar to replacing a damaged or failed car part.

Why is maintenance important? +

Stormwater treatment devices are designed to remove sediment and other contaminants from stormwater runoff. Over time, the accumulated contaminants can clog/block the treatment mechanism and are required to be removed to maintain the design treatment efficiencies. 

If the device is left unmaintained, it will no longer remove contaminants and will not operate as designed. This may result in dirty untreated water discharging into our waterways having detrimental effects on the ecosystems and marine life. This may also be contradictory to resource consent conditions imposed for your site.

Regular maintenance is essential to the operation of the stormwater treatment device and to minimise adverse environmental effects on downstream water quality. It is important that a maintenance programme is put in place and undertaken in accordance with the manufacturers specifications.

Who is responsible for maintaining Stormwater treatment devices? +

The asset owner and/or resource consent holder are responsible for ensuring the total onsite stormwater system, including any devices, are maintained in accordance with consent conditions.

A Body Corporate may also be responsible for multiple (unit title) lot developments.

When is maintenance of a Stormwater treatment device required? +

Maintenance frequencies can vary between each device, site location and land use. 

As a minimum we recommend a routine 12 month inspection to determine the need for maintenance, and a full maintenance clean if required.

Stormwater360 can provide a operation & maintenance guideline for all of our products upon request. Please contact our maintenance team via maintenance@stormwater360.co.nz for further information.

Do Stormwater360 New Zealand provide a maintenance service for their products? +

Yes. A complete list of services can be found on our maintenance page.

Please contact our maintenance team at maintenance@stormwater360.co.nz or 0800 STORMWATER360 to arrange maintenance services.

How much does a maintenance activity cost? +

The maintenance service charge will depend on numerous factors including size and type of device, geographical location and removed sediment mass. Please contact a Sales representative at sales@stormwater360.co.nz or 0800 STORMWATER for a no-obligation site specific quotation

STORMFILTER™ +

How much does the StormFilter device cost? +

The supply price will vary depending on the drainage catchment area, available hydraulic effect, cartridge size, target contaminants, media type & total number cartridges required. Please contact a Stormwater360 Stormwater Consultant at sales@stormwater360.co.nz or 0800 STORMWATER for a site specific StormFilter design and quotation.

How does the StormFilter work? +

Cartridge

 

During a storm, runoff passes through the filtration media and starts filling the cartridge center tube. Air below the hood is purged through a one-way check valve as the water rises. When water reaches the top of the float, buoyant forces pull the float free and allow filtered water to drain. After the storm, the water level in the structure starts falling. A hanging water column remains under the cartridge hood until the water level reaches the scrubbing regulators. Air then rushes through the regulators releasing water and creating air bubbles that agitate the surface of the filter media, causing accumulated sediment to drop to the vault floor. This patented surface cleaning mechanism helps restore the filter’s permeability between storm events.

What is the maximum catchment area a StormFilter cartridge can treat? +

The maximum catchment area that each cartridge can treat will vary depending on the geographical location of the proposed device and local/regional council hydrological guidelines. Please contact a Sales representative at sales@stormwater360.co.nz or 0800 STORMWATER for a site specific StormFilter design.

What traffic loading can the StormFilter system be designed to? +

Our standard StormFilter configurations are designed to withstand HN-HO-72 (NZTA's Bridge manual) traffic loadings.

We are able to design our structures for heavier loadings on request. Please contact a Stormwater360 Stormwater Consultant at sales@stormwater360.co.nz or 0800 STORMWATER for a site specific StormFilter design.

What are the minimum headlosses through the StormFilter device? +

The StormFilter™ is available in multiple (69cm, 46cm, & 30cm) cartridge heights to meet site-specific hydraulic needs and provide design solutions for site restraints.

Cartridge Size

Is it compulsory to have a physical drop between inlet and outlet pipe inverts? +

No, it is not compulsory. The inlet pipe can be set flush (at same invert) with the outlet pipe where available head allows. 

Preference is for the inlet pipe to be installed at same invert as the internal overflow weir to ensure operation of the StormFilter at the design water quality flowrate without surcharging the upstream pipe network.

What is the typical maintenance frequency of the StormFilter? +

Our standard StormFilter designs allow for an anticipated 12 month maintenance frequency. However, historical maintenance records indicate that some devices can last 18-36 months before a full maintenance clean is required.

We are able to size the StormFilter on a mass load basis, rather than a flow basis, to increase the maintenance frequencies to a desirable timeframe. Please contact a Sales representative at sales@stormwater360.co.nz or 0800 STORMWATER for a site specific StormFilter design.

 

What contaminants can the StormFilter treat? And which media is ideal for each contaminant? +

The StormFilter can be customised using different filter media in the cartridges to target site-specific pollutants. A combination of media is often recommended to maximise pollutant removal effectiveness.

Media

Can the StormFilter be added to modelling software? +

Yes.

 The StormFilter cartridges use a unique float-activated mechanism and hence cannot be modelled using traditional stage-discharge curves. Although the StormFilter is a passive gravity-operated device, it exhibits a switching behavior that is quite similar to the on/off switching of a stormwater pump. Hence, it is recommended to model the cartridges as a pump.

A modelling guideline and webinar for HydroCAD can be found at http://www.hydrocad.net/contech-filters.htm. The same guideline can be used for similar software.

HydroCAD Supported Product

 

 

 

ENVIROPOD® +

How does the EnviroPod® work? +

As stormwater enters a storm grate or catchpit/gullypit, it passes over the oil adsorbent pads (optional) and into the screening bag. Litter, debris, and other pollutants larger than the screening bag aperture are captured and retained, while oil and grease are reduced by the oil adsorbent pads.
If the screening bag is full or during high flows, overflow is released through the overflow apertures in the frame assembly.

EnviroPod

Can I use the EnviroPod® as a pre-treatment device? +

Yes. The EnviroPod® is also effective as a pre-treatment device for use in a treatment train with hydrodynamic separators, filtration devices, ponds and wetlands.

 

What are the available sizes of the EnviroPod®? +

The Enviropod® can be is available in the following standard catchpit sizes; 675x450, 450x450, 450x300, and 300x300.

We can also manufacture custom sizes for non-standard catchpit sizes. Please contact a Sales representative at sales@stormwater360.co.nz or 0800 STORMWATER for a site specific design and quotation.

What is the standard height of the EnviroPod®? +

The standard height of the EnviroPod® cage is 1.5m. This can be shortened (using bolt cutters) onsite or lengthened with additional cage extensions to suit the onsite catchpits.

What is the maximum inlet capacity of a standard Enviropod? +

Our standard EnviroPod® is able to provide treatment flows up to 10L/s for litter, debris, and other pollutants larger than the screening bag aperture.

Peak flows greater than the treatment flow rate are bypassed through the in-built overflow apertures in the frame assembly. Refer summary below for the most commonly used catchpit sizes;

EnviroPod spec

 

Can the EnviroPod® be retrofitted to existing sites? +

Yes. In many cases, it is often the most practical solution for existing sites as it can be easily retrofitted into new and existing stormwater catchpits, requiring no construction or land take.

What is the recommended maintenance frequency for the EnviroPod®? +

We recommend that the EnviroPod® is monitored and maintained in accordance with relevant local authority guidelines.

Typically Enviropod® filters will require maintenance between 3 & 12 months, depending on local site conditions, pit depth and the number of vehicle movements. The frequency of maintenance services should be reviewed at the completion of each service and modified if pollutant loadings deem this necessary.

How much does the EnviroPod® cost? +

The supply price will vary depending on the number of EnviroPods required and geographical location. Please contact a Sales representative at sales@stormwater360.co.nz or 0800 STORMWATER for a site specific quotation.

CHAMBERMAXX™ +

How much do the ChamberMaxx™ chambers cost? +

The supply price will vary depending on the region. Please contact a Sales representative at sales@stormwater360.co.nz for a quote.

What is the storage capacity of the ChamberMaxx™ system? +

The minimum installed storage volume is approx. 2.15-2.22m3 depending on the chamber unit. This includes the chamber itself and the surrounding aggregate (150mm above and below chambers). Refer below table for further information;

CMAXX Storage TABLE

 Additional storage can be added to the device by increasing the surrounding aggregate depth, length or width. Please contact a Sales representative at sales@stormwater360.co.nz or 0800 STORMWATER for a site specific design.

Can the ChamberMaxx™be used for soakage/infiltration? +

Yes. Click to see  ChamberMaxx™ under Green Infrastructure

What type of stone material is recommended for the ChamberMaxx™ system? +

We recommend a washed 40/20 drainage aggregate (i.e.no fines) with approx. 40-50% air voids. Alternative materials, such as scoria, may be used as long as structural properties are considered adequate for the proposed loading ontop.

Is it compulsory to specify an impermeable liner? +

No, however it is recommended for water retention or to prevent groundwater entering the chambers on sites with a high water table. We recommend further technical advice is sought from Geotechnical & Structural professionals for suitability based on site constraints.

Is a treatment device required prior to the chambers? +

A stormwater treatment device upstream of the chamber inlet such as the StormFilter, JellyFish or a VortCapture is preferred, but not compulsory. This will aid in reducing risk of contaminants entering the ChamberMaxx system and prolong maintenance frequency.

What is the minimum cover for traffic loadings? +

The ChamberMaxx has been designed to withstand 243kPa at the chamber crown.

We recommend 550mm for high-use traffic loads (i.e. HN-HO-72) and 400mm for low-use traffic loads.

What is the required bearing strength of the subgrade soils under the ChamberMaxx? +

We recommend an ultimate bearing pressure of 300 kPa, as per the definition of 'Good Ground' in NZBC B1, for the underlying subgrade soils/ground.

If the ground does not meet this ultimate bearing pressure from field tests (ie penetrometer), the existing ground condition must be assessed by an external geotechnical or soil engineer to determine if additional bedding and/or a suitable foundation is to be constructed.

What is the maintenance row? +

The maintenance row (also containment row) is designed to receive the first flush of storm events into the ChamberMaxx system, trap debris and prevent sediment/contaminates exiting the row.

What are the maintenance procedures for the ChamberMaxx™ system? +

We recommend an annual inspection of the ChamberMaxx™ system to determine if maintenance activities are required. Like all detention/retention tanks, the need for maintenance will depend on the sites sediment loading and buildup within device. This can increase significantly when a pretreatment device is not installed.

Maintenance is performed using a JetVac truck utilizing a high-pressure rear face nozzle (refer figures below) to back flush sediment and pollutants into the diversion manhole where they can be vacuumed out. For further information, please refer to our standard operation and maintenance manual


CMAXX MAINTENANCE1

 

CMAXX MAINTENANCE2

 

How long does a typical maintenance activity take? +

Typical maintenance can be undertaken in 0.5-1 day. However, this will depend on numerous factors including geographical location, the size of the ChamberMaxx system, sediment buildup within the system and time between last maintenance activity.

 

LIVEROOF® +

What’s so special about the LiveRoof® system? +

With its unique patent pending Soil Elevators™ and Moisture Portals™, the LiveRoof® system gives you the look and function of a conventional green roof, with the turn-key benefits of a modular system. LiveRoof® represents the best aspects of modular and conventional green roofs combined in one simple, attractive effective system. LiveRoof® is an integrated system designed by growers in conjunction with experts in the fields of architecture, roofing, logistics, and ergonomics.  It is designed to grow plants! Composed of recycled plastic materials, LiveRoof® is based upon sound horticultural principles.  It is earth-friendly, as well as rooftop functional and aesthetically pleasing.  LiveRoof® systems, because they are pre-vegetated at the nursery, require minimal maintenance.  Compared to site-built green roofs, which are time-consuming and costly to install and maintain, LiveRoof® offers a turn-key alternative that doesn’t require you to be a horticulturist.  LiveRoof® modules can be vegetated with various plant assortments to address your particular design needs and climate.  And if there is ever any need to make changes to the roof, LiveRoof® modules are easily moved aside and replaced after the work is done.

 

What is the biggest financial advantage of LiveRoof®? +

LiveRoof extends the lifetime of the roof; typical estimates are that a green roof extends the lifetime of a roof between 100 and 200 percent, by protecting the rooftop from ultraviolet radiation, large temperature fluctuations, drying winds, and punctures.  Not only does the roof last longer, but there is reduced membrane maintenance.  All this brings about significant cost savings over time.

 

Energy savings – What Can I Expect? +

Green roofs have been proven to bring about significant energy savings, particularly during the summer cooling season in which single story buildings can experience a reduction of greater than 25% energy use.  Plants transform heat and soil moisture into humidity, to create natural evaporative cooling. Each gallon of water that is transpired by the plants or evaporated from the roof surface liberates 8000 BTU of thermal energy.

Why doesn’t the LiveRoof® system use filter cloth? And, won’t the soil run out the drain slots? +

Filter cloth, like any filter, is designed to filter. Filters in time can plug up (think of your car’s air and oil filters, your furnace filter, coffee filter, etc.). If a green roof filter plugs up, it can cause flooding and the associated additional load on the structure as well as saturate media causing unhealthy plants.

 

Because of the aggregate nature of LiveRoof® soil, the soil stays in the LiveRoof® module as it would if you poured it into a funnel. It’s like the square peg in a round hole scenario. In addition to this simple act of physics, the roots of your LiveRoof® plants bind the soil together and hold it in place.

 

Why doesn’t the LiveRoof® container have moisture reservoirs? +

Because it was designed by horticulturists. Horticulturists know that moisture reservoirs store water. Stored water is oxygen deprived, and roots sitting in oxygen deprived water become diseased with fungal and bacterial rot. This weakens the plant, may spread to the crown of the plant, and may perpetually handicap the plant and predispose it to secondary disease and insect infestation.

What is so special about LiteRoof growing media? +

Unlike cheap plant mix soils that have high organic content, LiteRoof® soil is predominately composed of high quality lightweight inorganic aggregates, contains a special clay particle to bind nutrients, and is formulated with disease suppressive organic material at a level that is consistent with ecologically sustainable soil/plant communities. LiteRoof® growing media is designed to last indefinitely and to not substantially shrink over time. Cheap mixes with high levels of peat and compost will decompose and wash away as humic acid. Perlite after several freeze thaw cycles may shatter repeatedly and turn to dust. It may also float to the soil surface after heavy rains, then blow away when conditions are dry and windy. Incorrectly designed mixes may also have an excessive amount of fine particles that will end up getting washed into gutters, and into the stormwater system.

How much does the LiveRoof® system weigh? +

The LiveRoof® system weighs approximately 150Kg/m2. (with a media depth of 100mm) when fully vegetated and saturated.  The LiteRoof® growing media follows FLL standards, enhanced to reflect current research regarding sustainable organic content.  We have intentionally avoided excessive organic content, which will shrink excessively over time due to decomposition.  Likewise, we have avoided perlite which may break down during the freeze thaw cycle.

 

 

 

Can I retrofit my existing building? +

It depends on the load capacity of the existing building.  Also, some older buildings can be redesigned for the additional weight of the LiveRoof® modules.   A qualified engineer must always conduct a thorough analysis

Does LiveRoof® need irrigation? +

The need for irrigation (beyond normal rainfall) will depend upon the plants selected, the local climate, and specific weather patterns.  Under normal circumstances, supplemental irrigation is seldom required.  Even so, we suggest a backup irrigation system in the event of prolonged hot, dry, windy, sunny weather.  During very long bouts of dry weather, plants can go dormant, shrink up, and expose soil. This can increase maintenance requirements as weeds can become established in bare soil. Excessively dry soil also causes the evapotranspirative cooling effect of the green roof to be reduced.

 

Irrigating, even once per month during protracted dry weather, can keep your green roof looking its best and pay dividends through maintenance reductions and evaporative cooling. Irrigating during protracted hot dry weather is a personal choice, the cost is minimal and one has the piece of mind that if ever needed, the water will be there. Backup irrigation systems can range from spigot and hose to overhead irrigation (similar to what one might have in one’s yard.)

What are the best plants to use with the LiveRoof® System? +

Different plants are used for different climates and different functions. Plants with a higher water requirement will generally be better for evapotranspiration (cooling and stormwater management), while water conserving plants will generally require less irrigation and maintenance. Plants that have extreme drought resistance through some means other than the root system such as succulent, water-holding plants like Sedums, Alliums, Sempervivums, Delospermas and a few others will the most hardy greenroof plants in a dryer climate.  These plants both store water and have a special type of metabolism called ‘Crassulacean Acid Metabolism’, CAM for short.  CAM plants are unique in that under drought conditions their stomates (leaf pores) are open at night rather than during the day, as is the case with most plants.  CAM plants exchange gasses (oxygen and carbon dioxide) in the dark when it is cooler and less windy.  CAM plants are up to ten times more efficient with water conservation than non-CAM plants.

 

LiveRoof® plants have been selected for the extreme conditions, disease and insect resistance, long life, low maintenance, and beauty.   Plants are selected by local horticulturists in order to meet the above objectives as well as the local climate and customer preferences.

Can I grow edibles with the LiveRoof system? +

Numerous vegetables, herbs, and select fruits (such as strawberries and melons) may be grown on intensive green roofs that receive frequent watering, have ample sunlight, and have proper soil.

 

Edible plants require sufficient nutrients to support their rapid growth cycle and the energy needed to bear fruit.

When growing produce on green roofs, a blend of organic soil and traditional green roof growing media yields the best results; however, the soil will need annual amendments to maintain volume and provide sufficient nutrition.

 

 

What is the urban heat island effect? +

Simply put, it is the temperature difference that exists between urban areas and their surroundings.  Urban areas tend to be from 7 to 10 degrees hotter due to the concentration of heat-absorbing buildings, pavement, and hot air from cooling systems.  The bubble of hot air that encloses cities is in large part due to lack of vegetation and is a great contributor to smog, ozone and dust (from artificially created air currents from the rising hot air).  The urban heat island effect has also been shown to create unique weather patterns within the city, with drought, high winds and electrical storms being more common than surrounding rural areas.

How does the LiveRoof® system help mitigate the urban heat island effect? +

Traditional rooftops are usually covered with tar, shingles or stone. As a result, they absorb sunlight.  On sunny days with an air temperature of 35°C city roofs can easily reach temperatures of 79°C or more!  The LiveRoof® system acts like a protective umbrella above the roof to shade and insulate buildings, avoiding the heat island effect associated with traditional rooftops.

 

Plants, of course, release oxygen and evaporate water, a process known as evapotranspiration, and act like evaporative cooling systems to make the air surrounding them considerably cooler.   By implementing a LiveRoof® system, the combined benefit of eliminating the heat generated by a non-vegetated rooftop, along with the evaporative cooling effect, is significant.

 

How does the LiveRoof® system reduce stormwater runoff? +

In urban areas, impermeable surfaces (streets, sidewalks, rooftops etc.) dominate the landscape, preventing rainwater from following a natural cycle of absorption.  Instead, as much as 75% of the rainwater runs into sewer systems.  Carrying contaminates from the air and roadways (salt, oil, mercury, etc.), this water flows untreated into lakes and streams.  In some cases, it may cause overflows of sanitary sewer systems, causing the dumping of untreated sewage.  In contrast, LiveRoof® green roof surfaces can absorb up to 99% of a 2cm rainfall, reduce runoff, lessen the risk of sewer overflows and flooding, and to some degree filter the water as it percolates through the LiveRoof® soil.  Even when a rainfall is such that it can not all be absorbed by your LiveRoof®, the excess rain that runs through the media is filtered and delayed until after peak flows, which allows additional time for sanitary sewer systems to handle uncontrolled runoff.

How does the LiveRoof® system reduce noise? +

Plants, soil, and trapped air and moisture in the soil are great acoustic insulators.  Studies have shown that green roofs can reduce indoor sound by as much as 40 decibels, a benefit not lost on those that work close to overhead highways and airports.

 

Where can the LiveRoof® system be used? +

LiveRoof® works well roofs less than 20 degree pitch (but can be installed up to 30 degree roof pitch), on industrial, commercial, institutional, governmental and residential buildings.  LiveRoof® works on any building where the building is appropriately engineered and the owners are progressive-minded and value the many economic, environmental, and health benefits that come from vegetated roofs.

Can the LiveRoof® system be used in non-roof areas? +

Certainly—median strips, patios, plazas, and malls are also great opportunities to use the LiveRoof® system.

 

Can I lift up a LiveRoof® module if I want to access my roof? +

Yes, it’s relatively easy. First, using a flat bladed shovel, probe the planting to locate the container edge. Then peel away some plant material. This is easy to do as the root systems of LiveRoof® plants is fibrous and easy to separate (not at all like sod). Using a sturdy pair of pliers, lift up and remove the exposed module. Any additional modules may be removed by trimming around them with the handle of a spoon and lifting them up. Once you are finished, replace the modules. Note: Never use sharp instruments around roof membranes

What incentives are available for green roofs? +

As energy demands rise and smog and other pollution impacts our cities, many cities and towns are encouraging “green” building methods, including green roof systems.  Cities also encourage green roofs to reduce storm water runoff, to protect the ground water, lakes, and streams, and to conserve energy.

 

Be sure to check with your local authority to see what is in place in your area.  Don’t assume that nothing is available.  Cities and towns benefit greatly from green roofs, and site owners can potentially increase their building site coverage with a greenroof, as well as reduce onsite detention/retention requirements.

 

Can LiveRoof® modules be cut to fit odd dimensions and angles? +

Yes, LiveRoof® modules can be cut to size and shape, either while pre-vegetated or empty with the use of a radial arm saw (with masonry blade) or reciprocating saw. When custom cutting LiveRoof® modules, the cut side should abut the non-cut side of another module, in order to contain the soil and minimize the work of installation.

 

If the cut side ever abuts edging, it should not be edging that is located on the low, draining side of the roof.  Always fit modules tightly against edging or parapet or surround with drainage fabric for added security.

 

Can I walk upon my LiveRoof® plants? +

Yes, you can do this a couple times a week without causing permanent harm. If you want to avoid walking on plants, paths or walkways can be incorporated into your LiveRoof® design.

GRASSCRETE™ +

How much does GrassCrete cost? +

The 150mm deep GC2 GrassCrete formers are $28/m2 + gst ex Albany, Akl.

What is the cost of a GrassCrete driveway vs. a plain concrete driveway ? +

It is hard to know the exact cost vs plain concrete driveways as it depends on the contractor used but in our experience, it works out similar. GrasscCrete requires less concrete as it has a high amount of voidspace, but it requires more labour to place, melt out former tops and fill with soil/grass seed.

Do you remove the plastic formers after the concrete is set? +

The plastic formers remain set in the concrete, however, the tops are melted out using an industrial gas torch (the type used to apply bitumen roofing membrane), this creates the void that is filled with soil.

Can GrassCrete be used on a steep drive? +

Yes, GrassCrete can be laid on sloped surfaces, however, you will require a lower slump concrete mix so it doesn’t run off the slope – this will require a bit more working of the concrete to finish it than a flat driveway where it would be simply pulled across top with squeegee.

What is the mesh used on top of the formers? +

The reinforcing mesh is 200mm x 200mm x R8mm SE82 mesh sheets from Fletcher Reinforcing.