GardenCadet Wrote:
After watching it loose water at a time when evaporation should have
been low, i have come to the concusion that dropping water levels in my
pond could be due to a small leak (caused possibly by birds). I need to
find this leak and if possible fix it but i have no i dea where to
start. I know roughly the area, but narrowing this down is proving
difficult.

can any one suggest any tips for locating the leak please?


First switch off any pumps that pump water out side the liner and see
if the level drops with the pumps off. If it doesnt drop the the
problem is somewhere in the course followed by the moving water.

If that is unsuccessful and the leak is not deep let the pond's level
drop until stable, the leak is then just above the water line but

If you let the level drop to a stable level and still cant find a hole
look for any folds that could be creating a wick, failing that add an
inch of water and then dribbling in some milk around the edge of the
liner, look for currents in the milky water

As a LAST resort that personally I doubt I would risk, the risk being
that underlay may float out of position or if the walls are soil, the
sides of the pond sight will collapse, put a hose pipe under the liner
and flood the site. Once the water outside the liner is level with the
pond water the liner may start to collapse and the pond level may start
to rise as the liner crushes. Look for a plume of dirty water jetting
into the pond.
If the liner is totally free to move as it pleases, ie non rigid and or
not held in place by plant pots etc then this may not work as the liner
will simple crush with no flow from the outside through the hole.
Assuming the liner is 'constrained', slow the inflow rate to a one that
will just keep the 'flood water' level just above the pond level but I
wouldnt allow the pond level to rise by more than an inch. If you are
near the inch rise in level I'd stop the flooding and actually remove
the water from outside the liner and start agian. As soon as you find
the hole mark it and start sucking water out from under the liner but
that is best done steadily, if you suck the water out too quickly the
liner is likely to seal around the suction line and starve the suction
line. If you pond walls are soil I would simultaneaously start topping
up the pond and let the pond sit, full, for a couple of days to assist
with stabilising the soil. After a couple of days drain the water to
allow you to fix the leak

Note the risk of soil walls collapsing etc is real so this is a LAST
RESORT




--
sean mckinney