Quenching a Thirsty Land: A Water Reservoir Project in Sundargarh, Odisha

A new water reservoir in Sundargarh, Odisha, was lined with two Ocean geosynthetics: 12,000 sqm of Ocean HDPE Liner-1.5MM as the impermeable barrier, laid over 12,000 sqm of Ocean NonWoven Geotextile-250GSM as a protective cushion. The reservoir stores rainwater for the community, and the lining keeps that water from seeping into the ground.

Sundargarh faces water scarcity and erratic rainfall. Most of its rain arrives in the monsoon months and runs off quickly, so water has to be captured and held for the dry season. A reservoir that leaks defeats the purpose.

Project snapshot

• Location: Sundargarh, Odisha
• Application: Water reservoir lining
• Barrier: Ocean HDPE Liner-1.5MM, 12,000 sqm
• Cushion: Ocean NonWoven Geotextile-250GSM, 12,000 sqm

The challenge: holding the water

The main job of a reservoir lining is to keep the water in. Traditional reservoirs rely on concrete or compacted clay. Both can crack and leak over time: clay shrinks and cracks when it dries out between fillings, and concrete cracks at joints and wherever the ground settles. Each crack becomes a seepage path, wasting water and, for some stored liquids, contaminating the ground. Factory-made alternatives such as geosynthetic clay liners and HDPE geomembranes avoid most of these problems.

The barrier: Ocean HDPE Liner-1.5MM

Across the base and sides of the reservoir, 12,000 sqm of Ocean HDPE Liner-1.5MM was laid. High-density polyethylene is effectively impermeable, so once the panels are welded into one sheet, seepage losses are reduced to almost nothing and the collected rainwater stays in the reservoir.

• Impermeability: HDPE has a very low permeability coefficient, so leakage through an intact, well-welded sheet is negligible and the reservoir holds its full capacity.
• Durability: The liner resists UV radiation and chemical degradation, and a 1.5 mm (1500 micron) sheet has good puncture resistance. That means a long service life with little maintenance.
• Lower site impact: A thin liner replaces thick layers of imported clay or concrete, so less material is dug, hauled and placed.

The cushion: Ocean NonWoven Geotextile-250GSM

Under the liner, another 12,000 sqm of Ocean NonWoven Geotextile-250GSM was laid. GSM is mass per unit area, so a 250 GSM fabric is a medium-weight, felt-like layer. It does three things:

• Puncture protection: The geotextile cushions the liner against stones and unevenness in the subgrade. Under the weight of a full reservoir, a sharp stone pressed into a bare liner is the most common cause of punctures.
• Drainage beneath the liner: The open fibre structure lets small amounts of water or gas trapped under the liner move away, which reduces the uplift pressure that can lift or stress the sheet.
• Cost: A geotextile is cheaper and quicker to place than a thick bedding layer of sand.

How the lining is built

On a reservoir of this type, the bed and slopes are first trimmed and compacted and cleared of roots and sharp stones. The geotextile is rolled out with overlaps between strips, then the HDPE panels are deployed over it and welded, usually by double-track hot wedge on long seams and extrusion welding at details. Seams are tested by air pressure and vacuum box, and the edges of both layers are buried in an anchor trench at the crest.

Result

• Water storage: The impermeable liner minimises water loss, so more water is available to the community.
• Long service life: The durability of both layers keeps the reservoir working for years.
• Environmental impact: Less material is excavated and hauled, and water that would have been lost to seepage is conserved.

Ocean Non Wovens Pvt. Ltd. manufactures HDPE liners and non woven geotextiles for reservoir, pond and canal lining. Contact us to discuss liner and geotextile grades for your water storage project, or see more on the pond liners page.