Re-lining of Large Pond

This project was to re-line a leaking pond at the foot of the south downs. The original liner had been poorly installed with no protective felt underlay and was leaking possibly due to the fact that every winter for some years the ground water rising from the chalk below lifted it to the surface of the pond for weeks until the springs subsided.

The old liner was removed and the pond deepened slightly and re-modeled to include planting areas in the margins then prepared for the new liner with an anchor trench dug around the perimeter to secure the felt and liner within.

Prior to installing the liner a land drain was installed from the centre of the pond falling to a point outside the curtilage of the pond adjacent to the existing outlet/overflow channel.

Once clear of the pond a 90 degree bend was attached and a riser bringing it to ground level. Now, during periods of excessive ground water a submersible pump could be lowered into the land drain to remove the water and prevent the liner from lifting and damaging itself.

Withe the land drain installed the new felt underlay and liner could be laid out and the works completed including creating marginal planting areas in the corners.

A new pumping system was also set up to circulate and aerate the water around the two ponds.