Precast Stormwater Products


Twinstar Precast will cast your Stormwater related slabs to your requirements. Stormwater slabs are designed and manufactured according to your need, shape and size.

We cast slabs for:

  • Light Duty, Medium Duty, Heavy Duty or Extra Heavy Duty applications.
  • For shopping Centres, Distribution Centres, Parking Areas, Residential and much more.
  • We offer the service of casting in Cast Iron Grating, as well as Polymer Gratings.
  • Slabs for Junction Boxes can be made in any shape and size to fit your specific Stormwater Junction Box.

Our Experts

Annemerie Coetzee


Andre Claassens

Production Manager

Stromwater Channels

We offer a range of Stormwater Channels including Half Round Channels, Equal Leg or U-Channels, Taper Chute Channels and other stormwater drainage channels.

Channels can be casted to be used as open channels or casted with Angle Iron inserts to accommodate grids

Stromwater Specifications

Twinstar manufactures a few standard stormwater channels but we offer the service of casting channels to suit your specific need. Equal Leg or U-Channels can be casted to a height and width that is custom made to suit your site conditions and flow capacity.

Channels are also casted in Medium Duty of Heavy Duty depending on the application. Extra Heavy Duty Channels to take Heavy Duty Vehicle Traffic can be casted with Angle Iron Supports to fit gratings to accommodate Shopping Centres, Distribution Centres and Transport and Logistic Yards.

Water Channels

  • D7 Channel 750mm Long 320 x 88
  • D8 Channel 915mm Long 410 x 180
  • D9 Channel 500mm Long 450 x 180
  • D10 Channel 500mm Long 500 x 225
  • D11 Channel 500mm Long 660 x 225

Precast V-Drains

V Drains are casted to suit site requirement.
We have a standard V-Drain of 1200mm wide.
Any other V-Drain will be quoted on request and the length will be determined by the size required and the calculated weight.


Equal Leg U Channels

Channels can be casted to be used as open channels or casted with Angle Iron inserts to accommodate grids.

Depending on the application we manufacture a Medium Duty U-Channel or a Heavy & Extra Heavy Duty Channel to accommodate traffic areas.

Channels can be covered with solid slabs or grids.
We offer polymer grids directly from our factory, or alternatively Rectagrid or Mentis Grid can be used.

These grids are not supplied with the channel but Twinstar will supply the dimensions for easy ordering from your supplier

Extra Heavy Duty Channels

Extra Heavy Duty Channels designed for  high volume    traffic areas or  heavy duty   vehicles


Any other sizes can be manufactured on request as we specialise in custom sizes and once-off items

Channel and Kerb Inlets



D7 Channel

D9 Channel

Equal leg channel

Kerb Inlet Slab

Kerb Inlet With Grating

Precast V-Drains

Taper Chute Channels

Half round Channel

Grid Inlets


Grid Inlet & Stormwater Manhole Slabs

Grid Inlet Slab

Grid Inlet with Polymer Grid & Frame

Slab with Double Polymer Grid & Frame

Slab with MD Cast Iron Grid

Stormwater Slab

Junction Slabs


Custom Made Junction Box Slab

Custom Made Junction Box Slab 2

Custom Made Junction Box Slab 3

Stormwater Manhole Slabs


Coverslab with Lid

Field Inlet Slabs

Kerb Inlet Slab

Slab with Lid

Frequently Asked Questions

Do you have branches?

No, our only branch is in Olifantsfontein, Gauteng

Can I order only one item?

Yes, we accept any number of orders. Even once off items.

Can I order only one custom product

Yes, we are ready to handle any custom order. 

Can I get a quote?

E-Mail your request with drawings or dimensions to us. Please include company detail quantity required and delivery address in your request.

Can I order a custom product?

Yes. Twinstar specializes in custom precast concrete products. 

What is your lead time on orders?

Lead time depends on the product and quantity ordered and will be confirmed at quote stage.

Can I supply my own cast-in items?

Yes, you can supply lids, grids, vents etc for us to cast into you product.

Do you have card facilities for payment?

Unfortunately we do not have card facilities. We accept Cash, but prefer EFT payments

Are you registered on the Central Supplier Database?

Yes – Registration Number MAAA0946926