Hi, I have a 1.2 acre pond that is now full of silt. 5 - 20 cm is water depth, silt is between 2ft - 5ft.

Which machines would you use to empty this?

I would like the removal of silt to take no more than 6 weeks.

I have a field to dump the silt which is 500m away.

Plan is to empty lake and wait a few months for silt to dry out and use an excavator and dumper. Pond is clay lined. Not sure on machine size.

Also have a problem that pond inlet has a lot of flow at times and that will need diverting. would a trash pump be powerful enough? Would be easy if i could dig a diversion channel but there are lots of trees around the pond and the tree roots will get damaged. Diversion length is 200m.

Any advice would be great

Thanks

You're probably out of luck on the 6 weeks. It takes time for that stuff to dry out enough to work with.

My 1/4 acre pond (2 foot of water over 8 foot of silt at the deepest part) had the dam broke in april/may time frame and the 8' of silt was able to be removed in October. It was still very pudding-like, but was manageable. The excavator was a medium sized track loader (8-9 foot track width) that picked up/ pushed the muck through the breech in the dam. It only took a few days to clean the pond out and replace the breech with stored clay, but it took months of favorable weather to dry it out enough to work with.

Hi, sorry I meant 6 weeks for the mechanical excavation part.

I will drain the pond and wait 6 months.

No point in removing anything, if you don't identify and fix the source of this silt.

Yes thats true, the pond has not been desilted since the 70s and I don't think it was done properly either.

There trees all around the pond, I guess some silt is leaves, hopefully I can just treat it every year with lime or calcium.

When it rains heavy the pond does go brown so I would need a silt trap or sediment pond.

Stuff from the trees (organic waste) and silt are two different things.

Silt is dirt, dirt don't decompose.
Organic waste comes from something that used to alive, like leaves, weeds, fish, poop, etc. This stuff breaks down over time. Breakdown time can be sped up, with some help.

You need to figure out what the stuff is, then come up with a plan.

What does it smell like?

I would say it smells a bit like sewage