What pump would lower a lake 10 m?
What pump would lower a lake 10 m?
(OP)
I'm not a pumping expert but need to figure out whether it would be possible to lower the level of an alpine lake by pumping so that a water intake can be installed.
Facts:
1. The lake is about 700 m long, 200 m wide.
2. The inflow is about 2 m3/s.
3. I need to lower the lake level 10 metres
4. The lake is in a high alpine, remote location where there is no power. There will be 4 wheel drive and heavy equipment road access to the site so I can bring in generators and pumps.
5. I can afford to take a couple of weeks to lower the water, so I figure I need to be able to pump out at 3 m3/s (2 m3/s to deal with inflow, and another 1 m3/s to actually lower the water level).
So any advice on how I might do this, and where I might get more info on the WEB would be appreciated.
Facts:
1. The lake is about 700 m long, 200 m wide.
2. The inflow is about 2 m3/s.
3. I need to lower the lake level 10 metres
4. The lake is in a high alpine, remote location where there is no power. There will be 4 wheel drive and heavy equipment road access to the site so I can bring in generators and pumps.
5. I can afford to take a couple of weeks to lower the water, so I figure I need to be able to pump out at 3 m3/s (2 m3/s to deal with inflow, and another 1 m3/s to actually lower the water level).
So any advice on how I might do this, and where I might get more info on the WEB would be appreciated.





RE: What pump would lower a lake 10 m?
When calculating the number of pumps required you have to include extra units to allow for any breakdowns, any units off-line for servicing as well as off-line when repositioning pumps to a lower level as the lake level falls, this is necessary to keep the suction lift to a minimum and 10 metres is beyond the maximum suction lift.
You need to plan for pumps to be staged to lower levels as the lake level falls and staged to higher levels at completion of the works as you withdraw the pump units.
Other important factors usually overlooked in jobs of this nature are, how much water is there in any surrounding water table (which needs to be included in the total amount to be pumped) and what will be the additional inflow if it should rain during the operation.
Questions
1. Where are you?
2. From your pumping position - what will be the head on the pump unit/s to the disposal point.
3. what is the elevation above sea level of the alpine lake
let's know if this is helpful or if you need any further info.
RE: What pump would lower a lake 10 m?
Alternatively, put diesel driven pumps on a barge, then the change in the suction lift isn't an issue.
I would suggest you look at godwinpumps.com, they do this sort of thing all the time. Having said that, your flowrate is pretty large, depending on the head required, you may be talking 5 or 6 pumps.
RE: What pump would lower a lake 10 m?
We're talking about an alpine lake in southwestern British Columbia, Canada, which is located at about 1100 metres elevation.
The idea of using a pump on a barge to minimize the head is a good one. The ultimate purpose here is to construct an intake for a hydro project. So in order to allow the lake to be used for water storage, the plan is to excavate a 10 metre deep trench out into the lake. Except for some lake bottom muds, most of the excavation will be in competent rock- but we need to lower the lake in order to allow the trenching work to be carried out.
Is it possible to use electric submersible pumps mounted on a small barge, with a generator on the shore (it would only be a few metres away). Like, what kind of pump would be needed to give us the flow capacity (3 m/s or more) that we need?
RE: What pump would lower a lake 10 m?
It should be possible to minimize the head by continually blasting out the trench as the lake level is lowered- which would mean that the maximum head would be maybe 2-3 metres.
RE: What pump would lower a lake 10 m?
Few other points:
Water from surrounding water tables shouldn't be an issue- the lake is in a rock basin. Also, I'm not too worried about unexpected pump breakdowns or an unusual rain storm- if that happened, the lake level would rise somewhat, and we've have to backtrack a bit, but it shouldn't be a big problem.
RE: What pump would lower a lake 10 m?
RE: What pump would lower a lake 10 m?
Maybe you can find a dozen or so trailerable dredges and wrestle them up there.
Mike Halloran
Pembroke Pines, FL, USA
RE: What pump would lower a lake 10 m?
But I'd like to have a better idea from some of you experienced hands whether there is something better, and how difficult (and expensive!) the present system I'm contemplating would be.
RE: What pump would lower a lake 10 m?
May be off the wall, but have you looked at a cofferdam?
Greg Lamberson, BS, MBA
Consultant - Upstream Energy
Website: www.oil-gas-consulting.com
RE: What pump would lower a lake 10 m?
It's possible that we may be able to advance the trench to the lake edge, and then slowly remove the remaining "plug" of granitic rock- basically, remove it one blast at a time, let the water drain out, then do the next blast, etc. until we get to the required depth.
RE: What pump would lower a lake 10 m?
RE: What pump would lower a lake 10 m?
BTW, thanks for all the help; this is great. If you can provide me with any rental pump suppliers in the Vancouver area, please do so.
RE: What pump would lower a lake 10 m?
Sorry, can't help with a rental company as I'm on the otherside of the world but can't see that you should have any problems sourcing this equipment.
However, I would be interested in putting a hire package together but logistics would be a problem
RE: What pump would lower a lake 10 m?
RE: What pump would lower a lake 10 m?
RE: What pump would lower a lake 10 m?
I had forgotten about Canadian Dewatering- I've used them in the city, but never in a remote site like this before. Fortunately, I designed the access road (under construction) for bringing in heavy equipment, so we do have reasonably good access. It is steep, and will soon be vulnerable to snow avalanche activity, but we weren't planning on doing too much more until next spring.
Artis: the stream coming out of the lake drops steeply after about 75 m (this is a pretty rugged mountain environment), so I'm planning on first diverting the stream into a bypass channel, and then cutting out a trench at the existing channel as I lower the lake level- that way, there should never be more than a couple of metres between the lake level and the ultimate intake trench, which will be entirely in rock.
RE: What pump would lower a lake 10 m?
RE: What pump would lower a lake 10 m?
OR,
You could make productive use of the winter, by harvesting the ice and sliding it down the road...
Mike Halloran
Pembroke Pines, FL, USA
RE: What pump would lower a lake 10 m?
RE: What pump would lower a lake 10 m?
Superelevate the road and build a snack shack at the top, and you can probably find people who would pay to ride a "bob-floe" down.
Mike Halloran
Pembroke Pines, FL, USA
RE: What pump would lower a lake 10 m?
I don't think sliding lake ice down the road would work- trust me, if you saw the site, you'd understand. Would be fun, though.
RE: What pump would lower a lake 10 m?
Good luck with it.
RE: What pump would lower a lake 10 m?
Ive done this in the Arctic.. similiar volumes and heads.
And Im pretty good with explosives if you need help there. I live in Alberta so I probably familiar with your site.t