Lake management...

[Ty Korrigan]

I've a old and regular client with a 27 hectare lake on the Brittany-Normandy border.

It has been drained to prevent the dam collapsing due to a leak.

Meanwhile, as the 'County Council' plus 2 local village councils and insurers lawyers wrangle over who pays, the weeds are a growing and nothing grows faster in rich century old lake silt than poplar and goat willow.

The lake never seems to dry out fully and is criss crossed by small streams.

The crust forms hexagonal plates which move like unstuck tiles.

We tried clearing an area with a Grillo 2 wheel tractor and scissor bar mower attachment.

Cumbersome and bogs down easily plus gets caught up what it has cut when reversing.

Also we cannot cross the streams which also run underground leaving a area of marsh.

I am inclined to go at it with a team equiped with clearing saws.

Another issue is what to do with the brush once cut? 

We cannot burn it and it will form mats which will block the sluice once the lake is re-filled which requires a diver to clear.

I tried to take a '360' series of images.

Any advice welcome.

Cheers

  Ty

 

 

[Mick Dempsey]

What about doing nothing? Assuming it'll get filled before spring.

 

 

27 hectare? You sure?

Edited September 17, 2017 by Mick Dempsey

[Mick Dempsey]

Why would you need a diver? The water runs over the top of the sluice.

 

Anyway this dam was compromised and we had to clear a load of trees on the left, (empty lake on the right) before a 360 repaired it.

 

The client tried clearing the vegetation, then gave up and left it. It must have died off and disappeared unable to survive submerged.

[Ty Korrigan]

30 minutes ago, Mick Dempsey said:

What about doing nothing? Assuming it'll get filled before spring.

 

 

27 hectare? You sure?

Can't fill it until dam is repaired.

It's subject to an 'Arret Prefectorial'

Weight limit over dam reduced to 3.5t which the farmers ignore.

It's been empty 4 years now. 27 hectares includes the marshland surrounding which is the breeding ground for the fish so I am told.

The whole property is worth 500k once the dam is fixed and lake re-stocked.

 Ty

 

Edited September 17, 2017 by Ty Korrigan

[eggsarascal]

I always thought water went over a weir and under a sluice via a gate, or penstock, or similar.

 

 

[Ty Korrigan]

There is a sluice low down in the dam almost at the level of the lake bed. It get's blocked with waterlogged vegetation.

Ty

[Watercourse management]

Roundup?

[Ty Korrigan]

Herbicides are strictly forbidden in this water catchment area.

Client has already been fined for using U.K Roundup marketed as safe around water on the dam itself.

Ty

[matelot]

If it was my lake I'd probably be getting an excavator in to de silt the entire lake. 

 

If you just want the vegetation removed why not fence it and put goats in?

 

I'd also be building a new outlet. Having a diver clear a sluice gate of vegetation has "corporate homicide" written all over it.

[Smig]

What about pigs or small cattle to graze down the vegetation?