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Water Management

We have been at the forefront of water management in the erosion control and earthmoving industries for over four decades. Whether it's information on Stormwater Retention Ponds (SRP), Floc Boxes™, Chemical, or Lamella/Silt Stopper Clarifiers that you are looking for, you will find it on this page. Here, we have gathered all you will need to know about the products and services we offer in this vital sector which more frequent and intense weather events are making increasingly critical.

Our services and product recommendations are customised accordingly to each specific job and our client's needs. Contact us to discuss your specific requirements.

Expert solutions to solve your toughest Water Management problems

For over 40 years, we have designed, installed, and maintained comprehensive Water Management products and solutions for government entities, commercial developers, and every other sized project. Enlarge any section to discover more:

Stormwater Retention Ponds (SRPs) - Managed products and services (including Bench Testing)

Pond management is critical for overall site health, especially in winter with its increasingly frequent rain events which can have a significant impact on your DEB (Decanting Earth Bund) and SRP (Stormwater Retention Pond). If you are under or overdosing your pond you may be creating an environment where the chemical is unable to perform effectively which results in the sediment taking longer than necessary to drop out. Solution: An Erosion Control Maintenance Program with Bench Testing Service.

Bench Testing is vital because the effective chemical dose window can at times be quite small.

Erosion Control will ensure you use the right chemical at the correct dose, and can provide weekly, fortnightly, monthly, or as needed monitoring (either prior to, or) after rain events. Moreover, with many years of on-site troubleshooting under our belt, we have a range of Chemical solutions at our disposal to help resolve that difficult to treat DEB / SRP

SRPs - Videos / Articles / Brochures
Floc Box™ - Environmental monitoring and reporting to take the hassle out of compliance

Since winning the 2016 IEVA award for Excellence in Innovation, Contribution and Education to the Sediment and Erosion Control Industry, Erosion Control’s Floc Boxes™ are to be found on sites all over New Zealand and Australia and are at the forefront of our drive to help settle out sediment from site run-off to prevent it entering the surrounding water system. But have you ever wondered how they work? Well, the principle is pretty straightforward:

  • The catchment tray discharges collected rainfall to a header tank
  • The header tank is designed to simulate the runoff hydrograph and discharges water to the displacement tank accordingly
  • When the displacement tank, which floats in the flocculant reservoir becomes sufficiently filled with water, reagent is displaced through the flocculant reservoir’s outlet point, flows to the dosing point and out into the sedimentation pond


  • Expert set-up
  • Priming and/or servicing to ensure rain-ready status
  • Weekly reports
  • Environmental monitoring of pH level
  • Turbidity checking
  • Refurbished Floc Boxes™ – kits and parts – on application

Contact our Team at Erosion Control to discuss your specific requirements.

Floc Box™ - Videos / Articles / Brochures
Lamella/Silt Stopper Clarifier - For size-constrained sites too small for SRPs

A part of water management on size constrained sites is the Lamella or Silt Stopper Clarifier. which essentially treats site or ground water (cleans it by dropping out sediment) when there is not enough room for an SRP.

Here’s a reminder about what our Silt Stoppers are designed for:

  • The ideal mobile gravity settlement device to provide a large settling area within a relatively small footprint making them the perfect option for space constrained sites
  • The Silt Stopper can be up to 20 times more efficient than conventional settlement tanks and ponds of similar footprint
  • The inclined plates in the units minimise the distance suspended particles need to travel to drop out to the bottom, promoting sedimentation and increasing overall efficiency
  • The Silt Stopper provides water clarification for a range of applications, including pumping and de-watering, drilling and piling, de-silting and dredging, vehicle wheel washing, process water treatment, groundwater treatment. In addition, site runoff can be treated either for discharge off-site or reused
  • The Silt Stopper can be fitted with a solar-powered telephonic PH and Turbidity monitor for real-time online reporting, including text alerts when water quality reaches levels of concern

Lamella construction is an evolving art as each site is different. They have to be serviced regularly and set up right, something that we excel at and which provides the following benefits:

  • Hassle free installation, maintenance and management
  • The supply and installation of all pumping equipment required to run the Silt Stopper water clarifying system
  • Flow automated to allow clients to work on what they’re best at while not having to worry about water issues
  • Worry-free compliance (records are all on hand when inspections happen)
  • Peace of mind that that the Lamella is being managed by experts and will work properly when it rains


Lamella/Silt Stopper Clarifier - Videos / Articles / Brochures
Water Treatment Chemicals

Erosion Control supply a range of products for coagulation and flocculation of suspended solids. We have expertise in all areas of flocculation ranging from sediment retention ponds and common clays to peats and other contaminants you may wish to remove from your water.

Polyaluminium chloride (PAC) is the go to chemical in New Zealand currently for use in rainfall activated systems on earthworks sites. PAC is a strong coagulant which uses aluminium ions as its active ingredient. Clays are generally negatively charged with clay particles repelling other particles (two negative charges will repel each other like two magnets) preventing settling. Aluminium ions are positively charged. When the aluminium reacts with the clay these charges neutralise each other leading to a electrically neutral particle. The particles will no longer repel each other and will therefore settle. Mixing is useful to get efficient settling as the particles will collide and bind to each other, causing flocculation to occur with the generation of “flocs” which are larger and heavier than the individual particles. 

Alternative chemicals such as PolyDADMAC have also proven useful on difficult to treat clays and soils. PolyDADMAC is an organic polymer which acts as both a coagulant (it carries a positive charge) and a flocculant with its long polymeric chains able to bind multiple particles together.

Erosion Control has recently teamed up with Vital Industries to bring a new alternative flocculation product to the market. EcoSuperfloc is a Chitosan based flocculant and is a greener  and more environmentally friendly alternative to PAC. Chitosan is produced from Chitin which is found in the shells of crustaceans and as such is produced from a renewable resource.

Erosion Control is also able to offer any support in regards to chemical flocculation in any industry. Give us a ring if you have any questions.

Water Treatment Chemicals - Videos / Articles / Brochures

Why choose Erosion Control?

We believe we are your best choice for environmental contracting services in the North Island. We offer decades of experience, a range of effective solutions, and a track record of 100% compliance. Our “do it right the first time” philosophy means you get a reliable, professional team working with you.

Providing Creative Solutions

Time and again, we’ve witnessed this fact: Doing the right thing for the environment is the most cost-effective solution in the long run. Known for our consultative approach, we’ll team with project managers early in the planning stages to identify green solutions that meet your project and budget requirements.

Ensuring 100% Compliance

Throughout the design, installation, and maintenance phases, we bring an advanced level of expertise and regulatory knowledge to our clients’ projects. Starting with the planning process, our clients rely on our guidance and expertise throughout the entire construction process. 

Offering best-management practices

We implement tried-and-true best-management practices, plus we’re on the forefront of the latest advances. Our clients appreciate that we take time to talk with them, educate them, and help them determine whether new approaches, procedures, or leading-edge technology may suit their site’s needs.



171 Postman Road
Dairy Flat
Auckland 0794


45G Duke Street
Hamilton 3204


8:00AM - 5:00PM


0800 787 2966


PO Box 130