Dam sealing for water storage and aquaculture

damsealA proven product is DamSeal, our West Australian Bentonite, rich in calcium, particularly suited to sealing dams and ponds when applied correctly. Bentonite has high levels of absorption qualities, which allows the clay to swell and create an impermeable layer.

Bentonite based liners or barriers systems are very effective, long lasting systems for water and wastewater and contaminant management.

The seal is 'plastic' so does not readily puncture.

Barrier systems

Common uses of these systems:

  • Lining/sealant for dams and ponds to reduce water losses through soil
  • Lining/sealant of dams and ponds to control movement of pollutants through dam substrate
  • Adsorbent liners and barriers to control movement of pollutants through soil in ground water.

The system is effective as a barrier system to restrict the movement of water and dissolved chemicals out of storage ponds or through soil profile.

The bentonite barrier system also adsorbs metals, hydrocarbons and other organic and inorganic chemicals. So bentonite based containment systems restrict movement of water and the movement of toxic chemicals.

Damseal with Bentonite A Damseal, our Watheroo Bentonite, is a proven product particularly suited to sealing dams and ponds when applied correctly. Damseal is not only environmentally safe, but because it is 100% West Australian, it is now an extremely cost effective method of sealing water storage. Bentonite may be used in several ways depending on the soil type and whether it is practical to empty the dam. For dry dams on light or loam soils, a mixed blanket is worked into the soil, and on heavy soils, a pure blanket would be required (similar to a clay lining).

Where a dam still has water, the best application method is to broadcast the Bentonite on the water surface. Rates of application for the above methods are reliant on soil structures and specific conditions within the dam. Our guidelines contain information to assist you in selecting the appropriate application for your needs. A soil engineer or Bentonite Products WA is able to provide further assistance on request.

Vineyard Dam before treatment

Vineyard Dam at Narrikup 17/2/2001

Vineyard Dam after treatment

Vineyard Dam at Narrikup 17/11/2001, after DamSeal applied to the base and lower section of the embankment.

Damseal Application


The application of DamSeal to repair leaky dams should ideally be carried out when the dam is dry.

1. Method 1 for effluent ponds or water storage dams

The surface of the soil should be cut back by 300mm and DamSeal spread at the required application rate. The soil which has been cut back can then be respread over the DamSeal and compacted or rolled.

plasticitySlopes on which DamSeal is placed should not exceed a steepness of 3 horizontal to 1 vertical.

2. Method 2 alternative for effluent ponds with granular soils

DamSeal should be thoroughly mixed with insity soil or fill material at the recommended application rate. The DamSeal/soil mix should then be moisture conditioned with moisture content of +2% of optimum and the mix spread and compacted to 95% maximum dry density (AS1289.5.1.1-1993). It is recommended the DamSeal/soil mix be placed in 2 layers not exceeding 150mm.


1. Locate position on the upstream face of the dam directly in line with leakage / seepage on the downstream side of the dam.

2. Apply granulated DamSeal to the surface of the water in the dam directly upstream of the area where seepage or leakage has been noted.

3. As an alternative, mix DamSeal with water to form a slurry. Then using a pipe placed into the dam pour the slurry into the pipe which acts as a "tremie pipe" to allow the slurry to flow to the base of the dam.


Fine Grained Soils


Course Grained Soils.