Geobag

What is a geobag?

A geobag is a large geotextile bag made from polyester or polypropylene fibre. The fibre is processed — by spun-bonding into a double-sided ironed and pressed needle-punched nonwoven, or as a woven fabric — and then sewn into a bag of specified dimensions. On site the geo bag is filled with sand, soil or fertilizer to suit the local conditions, forming a heavy, stable unit. Because the geotextile is permeable, water drains out through the fabric while the fill stays inside, so the geobag both contains material and dewaters it. SIGMA supplies the geobag as a sand geobag, a woven geo bag or a non woven geo bag.

Where geo bags are used

Geo bags are widely used for shoreline, riverbank and slope protection, where rows of filled bags armour the bank against erosion and scour, and for marine structures such as groynes, breakwaters and revetments. The same permeable, high-strength fabric makes the geobag ideal for dredge-material containment and for sludge and slurry dewatering — the geotextile bags for dredging retain fine solids while filtered water passes through, reducing volume efficiently. Filled bags also serve as fast, cost-effective flood and embankment protection.

Shoreline protection and vegetated erosion control

For erosion control the geobag is laid in rows or stacked to armour a riverbank, embankment or shoreline against wave action and scour. Because the filled bag is heavy and permeable, it stays put while letting water drain through rather than building up pressure behind it. The geo bag can also be turned into a living, vegetated wall: filled with soil, native seed and plants, the bag is colonised within a few weeks as roots grow through the fabric and into the native soil, forming an ecologically sound erosion-control system with permanent structural strength. The UV-resistant fabric resists the chemical composition of the soil and is not eaten by pests, so the structure holds for the long term.

Geotextile bags for dredging and dewatering

A major use of the geobag is dredge-material containment and sludge dewatering. Slurry or dredged sediment is pumped into the geotextile bags for dredging, where the fine woven or nonwoven fabric retains the solids while filtered water passes out through the bag walls. This dewaters the material and cuts its volume sharply, with no special equipment required — an efficient, cost-effective way to handle high volumes of sediment, sludge or slurry. The same principle scales up to the larger tubular geotube for big dewatering and marine containment jobs.

Fabric, sizing and selection

The defining property of a geobag is the geotextile fabric — its tensile strength, apparent opening size and water flow — which follows the same ASTM methods and woven system as our geotube dewatering fabric. Both a woven geobag and a non woven geo bag are available: the woven fabric gives higher tensile strength and a controlled opening size for structural shoreline and containment work, while the needle-punched nonwoven offers strong filtration for dewatering. The opening (sieve) size is selected to retain the fill while keeping the bag permeable, so it can be tuned for sand, silt or sludge. Finished bag dimensions are custom-made to each project; there is no single public standard for the geo bag size, so it is confirmed per order. Tell us the application, fill and quantity and we will return a geobag price — see the geotube for larger tubular containment.