On Mon, 25 Aug 2008 09:29:53 EDT, Tony Raven
wrote:

I read that as diving bell the first time round ;-) If I hire someone
how will they do it?

I don't know, but in your search for someone to clear growth from the
bottom of a 3' deep pond, you may find someone with experience of
either clearing vegetation or making canals deeper and equipment for
such tasks. A dragline comes to mind, but I haven't seen any such
devices in operation in years. The bottom will be churned well, no
matter which mechanical means you choose.

I wondered about trying to get a rope round the
roots and then pulling them out with a tractor. Or is there an easier
way without digging them up to remove some of the vigour e.g. pruning
out all the leaves in the central crown and leaving just the floating
leaves?

Rope and cable have a danger of lashing you if they break, so I'd
suggest chain, since it is more likely simply to drop in place if it
breaks.

Sorry, I doubt there is an easy way. The problem is the feeder roots
extending from the tuber or larger roots are most numerous and extend
into the mud by 6 to 8 inches and anchor into about a gallon of mud
for every 6 to 8 inches of tuber, that is my guess, but it is heavy
and depending on the length of the tuber or big root the attached mass
could be more than I could pull with my feet on the bottom and lifting
up. This is all guesswork on my part, since I keep my lilies in 3
gallon buckets and divide them at least the second year, and many are
only allowed one year in a pot. To get them out of the pots, (They
grow till the pot is filled with no clearance between the mud roots
and pot sides.) I take them out of the pond turn the pots upside down
and walk away for a while. When the water drains out the plants fall
out of the pots and I no longer have the hand strength to break them
apart, so I use a hatchet to separate, or chop off the corms or leaf
sprouts along with a bit of the tuber for food and set them in a new
pot for next year.

I hope my guessing is helpful, but I've never seen anyone clear a pond
of water lilies. Another personal thought is the lilies will take
care of themselves settling as the nutrients are used at the present
points of rapid overgrowth. This is a guess based on an incident that
I caused. Once a year fertilizer spikes wasn't available locally, so
I picked a spike from a couple tree fertilizers that looked like they
might be close enough to work on lilies. They releases so much
nitrogen into the lily pot the plants hardly bloomed, however the lily
pads that are normally 6 to 8 inches were over a foot in diameter that
year.

I think you are very fortunate and I would simply add lotus to the
pond and in a few years it will cover the lilies and you could have
something like this:
http://www.koiphen.com/forums/showth...ighlight=lotus

I only had one plant per pot, but you could have a 100' diameter pond
of these beauties.
--
Hal Middle Georgia, Zone 8
http://tinyurl.com/2fxzcb