Help - Beavers

[Lowhead]

I have a low head hydro installation on a former millpond behind my house.  Basically I have a screened culvert with an 8 inch PVC pipe penetrating the earthen berm dam that feeds a box on stilts with an ES&D LH1000 turbine in it.  The head is 9.5 feet.  It's been working great since December but recently a family of beavers has taken up residence inside the boulders on the backside of the dam and are determined to plug up my screened inlet.  Every morning I go out and clean out logs, branches, rocks, leaves and mud and by the next morning my output is down to zero.  I don't want to shoot or trap them.  Any idea how I can get them to move out?  I was thinking maybe put a light out there?  If I just shut down the flow for a couple of weeks will they move on?  It isn't 10 feet from the spillway and they've never tried to block that up.  Someone gave me an infrared hunting cam that straps onto a tree.  I'm trying to catch them on video with it.  I couldn't figure out what was causing all this debris suddenly and one day there was this giant thing in the river watching me.  I'll bet he weighed 40-50 lbs.  I took a step towards him to take a picture with my cell and he took a step towards me.  We weren't 10 feet away from each other.  I blinked first and climbed up on the box.  He walked right underneath it so I don't think he's afraid of humans.

Another question that I'm hoping hydrosun can answer.  I also have a 48volt outback PV installation with 18 Kaneka GSA60 panels in parallel.  I'm thinking of running the hydro into my MX60 in parallel with the PV panels.  I'm losing a lot in my 420 foot wire run (strait to the batteries) and don't really car much if the PV panels run optimally.  My site for PV isn't great.  It was the price I had to pay to get a grid tie connection.

[TomW]

Beavers are hardwired to react to the sound of running water by damming up the flow.

Did you contact your local wildlife folks?

There may be audio or electronic non lethal methods to control them.

My casual reading over the years leads me to believe that they are  very tenacious critters when it comes to this damming activity.

I would start at your local wildlife control bureau / department and see what they suggest.

Maybe they will relocate them for you?

Perhaps you can discourage them from hanging around but even that may be illegal in some areas?

Good luck with it.

Tom

[Boss]

We've had beavers on our river over the years, most of the locals do not want them, for any number of reasons. They do kill a lot of trees, and I am a forester, so they don't hold any special place in my heart, but damn they do nice work, indeed beavers are considered to be the Earth's hardest working creatures, and I believe they deserve a lot of respect from man. Obviously I'm torn, so when they start fixing the head-gate to our acequia on the river something must be done, after all, nobody messes with irrigation water in New Mexico. Apparently our little fat floating furry engineers didn't read Milagro Beanfield war http://tinyurl.com/Milagro-beanfield-war.
The trick is to remove the sound of running water.
This is done by submerging the inlet pipe and placing a wire cage around it 

[TomW]

The trick is to remove the sound of running water.
This is done by submerging the inlet pipe and placing a wire cage around it  [/size]

That is an elegantly simple approach. If it fits the location anyway.

I read that book but don't remember the bit about beavers from it?

Tom

[Boss]

That is an elegantly simple approach. If it fits the location anyway.

  BTW I didn't invent this technique, I saw it on Nova, and the scientists applied it to several beaver dams in Canada to keep spillways and roads clear in whatever Canadians call National Parks.

And yes they did the trick with a simulated water leak using a portable PA system, the beavers were filmed during the night trying in vain to fix the speaker system leak, poor little guys.

In the Nova  documentary they used the submersed flex pipe with the cage on the end in a dozen different types of locations. The worst case scenario the beavers spent a great deal of time under water trying to figure out where the leak they could hear was. With the inlet so far from the sound of the water going into the culvert, or outlet pipe they could not figure it out.
At times the beavers did find the water flowing into the cage of interest, but they were unable to get branches to stick to the cage under water.
I don't have any first hand experience with this technique, because I assume the farmers here are too quick with the gun solution.
 

[Lowhead]

I really don't want to trap and kill them.   What I don't understand is since the spillway isn't 10 feet away with water pouring over it all the time they suddenly "hear" running water in my pipe.  My problem is I don't own the pond so I can't extend any pipe into it.  The pond is very shallow - only about 3 at its deepest.  I'd have to extend the pipe about 50 feet just to get it 3 feet underwater.  I should have used 10 or even 12 inch pipe but its' to late now that it's cast into concrete.  I'll bet it's the velocity of the water in the 8 inch pipe.  I'll try to think of a way to eliminate the sound.

Andy

[TomW]

So snag a low end Ipod or similar record the sound at your problem location hang it on a post somewhere else and play the loop as loud as possible thru computer speakers for low power solution or run a wire out and play the loop from the house on a speaker where you want them to work instead of your inlet? Combined with a submerged inlet it sounds like you could beat them at there own game in a non lethal manner maybe?

Disfunctional beavers may result.

Tom

[SeanR]

Hello,

In my 20 years of experience of managing Beavers the only way to not eliminate them would be to extend the pipe in the pond then use a 90 deg elbow pointing up. Then cut the pipe at the level you want to maintain the pond. The beavers seem to expect the running water sound to leave from the edge of the pond not for the water to pour out from the center.

Other than that the only way is to eliminate the beaver, otherwise asking the beaver to stop making a dam to float the wood is the same as asking him to stop eating.

Also with only 3 feet of water expect them to build up the dam many more feet, on the good side more head for your turbine 

I usually trap around 3 to 6 beavers a year on 3 lakes up here in Canada and every year the youngsters get kicked out of the lodge from down stream and come settle at our place. Beaver population is very healthy.

BTW somebody just found one big dam

http://www.vancouversun.com/technology/Canadian+beaver+seen+from+space/2994056/story.html

Sean

[greenkarson]

Finally a topic I probably have the most experience with.  BEAVERS! As a licensed nuisance trapper I've seen it all tried.  In a nutshell unless you want to spend all your time playing games with the beavers they have to go.  I've actually trapped for the railroads here in Canada. The screen fence method out in the water from the intake pipe does not work. They may for a week or so may be even a month but eventually they figer it out and plug it tight.  I trap dozens of these beaver fences every year. As the land owners stand in defeat watching from the shore.
  If you want to keep the beavers there. The only solution I've seen work is run your intake pipe out into the deeper water and keep it way up from the bottom put a small screen just over the end of the pipe.  So the whole thing is as sleek and small as possible maybe even put a 90 degree elbow pointing down.  So there is no surface that can hold Debree Make sure its away from any thing a beaver can start building from stumps, rocks, fallen trees.
 Beavers can be trapped live and relocated.  But actually relocating is illegal in a lot of locations without a permit.
getting them relocated will probably cost you a little money but money well spent. Belevie me You want them gone.

I remove about 90 to 100 beaver a year here in Ontario.

[greenkarson]

Drew up some hi tech drawings to explain what i meant about running the pipe out into the middle of the pond. 

[Boss]

thanks for that read world wakeup story GreenLarken.

[hydrosun]

Andy
Can you describe your electrical system? What voltages are you running the solar panels and the hydro? How many watts from the solar and how many from the hydro?  To run the solar and hydro into the Mx-60 you need similar voltages. The solar needs to be lower than 110 open circuit to give enough headroom to clamp the hydro at open voltage.  That the rule of thumb for crystaline panels, I don't have any info for amorphous panels like the Kaneka.  The solar panels should be rated at close to the expected amperage of the hydro when running at overspeed. This will ensure that no damage will be done to the solar panels when the MX-60 goes open circuit and the voltage rises and the hydro speeds up and the solar panels absorb the power until the MX-60 comes back on.  And last the total wattage from the solar and hydro shouldn't go over the ratings for the Mx-60. At 48 volts that is around 3000 watts. From the info you have already given it sounds like it should work to connect both together. The voltage of the ESD can be adjusted by rewiring but I don't know how it is wired now.
Chris

[ghurd]

I drove a road in Canada.  Somewhere between Clova and Maniwaki QC, IIRC, that was ~440(?) yards of beaver dam.  I have 35mm pics somewhere.

Beaver were eradicated around here 150(?) years ago.
Naturally, being natural, someone thought it was naturally a good idea to reintroduce them about 35 years ago.

They were "A Cute Oddity".  For maybe 3 years.  We all played nice.

They were "Determined".  For maybe 5 additional years.  We all played nice.

Starting about 20 years ago, sighting one in a previously uninfested area struck terror into the land owner's heart.
And it still does.
'Extraordinary times call for extraordinary measures'
We all tried to play nice.

Thankfully smallpox is not a cute fuzzy quadruped.
If that is an overstatement (it is) then maybe Dutch Elm Disease?
Reintroduce the mosquito?

I suppose suggesting a 22Mag on a full moon would be illegal most places, because most places they would be a protected quadruped.
I suppose suggesting to give them some wide berth concerning aquatic fleas, each biting a non-aquatic mammal at least once before departing, is not required.

"I really don't want to trap and kill them."
Then you already lost the war.

Just my experience.
G-

[XeonPony]

Back at Claholm falls in BC we just used good ol dynomite! fixis the issue real fast, best applied during the day while they're home

That or as the guy above said a 22 makes a good fix.

[Lowhead]

I think the beavers are going to have to be relocated - to another life!  I can't do the suggested pipe extension since I don't own the pond, just the dam.  I think the state has a program to remove nuisance beavers but only if they are flooding property.  It's illegal in MA to relocate them.  The dynamite thing isn't an option - they seem to be living inside the dam itself.  I'm probably not going to get much sympathy from the state and I'm trying to fly a bit under the radar anyways since they own the pond.   I'll give the iPod thing a try but I don't hold out much hope for that.

Chris, the 18 Kaneka GSA60's are all wired in parallel to the MX60 for 1020 watts.  Each has a 6 amp circuit breaker in the combiner box.  Their open circuit voltage is 92V but the nominal operating voltage is 67.   Kaneka's are capable if being wired in series for up to 530V so (I think) they should be able to handle the open circuit voltage of the turbine.  I'm running a grid tied Outback GVFX3648.  The LH1000 is not the high voltage version.  With 9 feet of head it should be capable of about 800-900 watts.  So far I'm only getting about 540 watts from it (before beavers) so I need to make some adjustments.  I have a 420 foot run strait to the batteries (8 Trojan T105's).  The cable consists of 6 positive wires (4sq mm each) and 6 negative wires.  This is solar wire that I got a good deal on.  It's supple enough to string through the trees and is direct burial rated for the last 50 feet that comes in underground.  I know it's a bit undersized.  I was planning to add more when I could afford it and then my source dried up.  The hydro voltage I measure at the house is 52V.  I'm thinking I have two options - boost voltage or add more wire.  I was going to add another MX60 but then I read some of your posts about running the hydro in parallel with the PV.  I don't really care if the PV doesn't run optimally.  I bought it used just to get a legal grid tie (hydro with FERC is a major hassle) and I don't have a great site anyways.  I think I can set the MX so it doesn't go open circuit and set it with the Upick mode.  The max system output of 1900 watts seems to be well within the operating parameter of the MX60. 

Thanks everybody.

Andy

[picmacmillan]

i have a bit of experience in this department..had to dust off 5 of them in 1 hour and 15 minutes here recently...and like you when i first moved to the north(ontario) i didnt want to kill them...but they can eat a 14" tree in one hour...myltiply that by 5 or so beavers per den and you can imagine the devastation....i have pictures to prove my dilemma....they have now destroyed over 20 acres of bush....to trap them will cost you money(here its 75 bucks each), unless its right beside the road and then the township will do it....calling the ministry, well i dont think that will go anywhere...they have bigger fish to fry....and relocating them has got to be costly?? besides where do they relocate them to?? even the fish and wildlife guys dont want crown land devastated by our buck toothed friends..... as many posters have suggested...tylenol .22 works well....and if you dont have a scope cut the subtle tactics and use the ole 12 gauge.....just my opinion ..    pickster...oh and one more thing not sure anyone has piped up on is...their feces leaves the water in a bad way..you can get beaver feaver(not sure the technical term)...and they say once you get that..you will wish you were dead..that alone is a good enough reason to not share youre water with them..

[Lowhead]

It seems that beaver trapping season ended on April 15 in MA.  I need to get a special "out of season" permit from my conservation committee if I can prove they are threat to human health, safety or will cause property damage by raising the water lever 1 foot or more.  Has anybody had any experience with these culvert protection fences? http://www.beaversolutions.com/culvert_protection_fences.asp  I might be able to sneak the cylindrical one under water where nobody will notice it.

[hydrosun]

Andy
I think you can just hook the hydro into the MX-60 with the solar panels. You'll want to adjust the PM alternator for maximum magnet strength for the highest voltage. And have the wiring in series wye for highest voltage.  The MX-60 will automatically set the input voltage to get the most power from the combination of the power sources.  I used to set the MX-60 not to sweep but it still would go open circuit once a day anyway. So now I leave the settings alone and it adjusts for daytime solar and overnight hydro only for maximum power.
  Do you know what the voltage is at the hydro turbine? That will show how much power is being lost in the wire. The MX-60 will help by raising the voltage and lowering the amperage. But only up to the open circuit voltage of the solar panels. I'm guessing it will run at about 75 volts during the day and maybe around 90 at night when the solar panels don't add any power.  
  Another reason for less than expected power is a mismatch in speed at the turbine because of how the hydro is wired and the voltage connected directly to the battery. You could temporarily disconnect the turbine from the batteries to get the open circuit voltage. Then you would know that it would put out the most power at 1/2 that voltage. But I'm always nervous doing that as it could blow the bridge diode.  Doing it with the solar panels connected would be safer but might mask the true voltage.
  I've also read that not getting the turbine housing properly sealed will cause a loss of available head. I haven't worked on these low head units but I think the alternator is the same as on the turgo that I have used.
Chris

[greenkarson]

Andy
    Please don't waste your time and money on the beaver fence.  This was the fence i was referring to in my first post i trap dozens of these fences every year.  If i had more time i would drive around and take some pics to show you how they are a waste of time.  I've seen these promoted all over the place. Even seen a documentary on TV here in Ontario about a group of beaver lovers going around putting these on coverts.  They were talking about how beavers would never have to be trapped again.  I laughed to myself the next day while i was securing my trap to the last little bit of fence post left sticking up out of a brand new trapezoid shaped beaver dam(a good solid dam reinforced with a fence to hold every thing in place)
    Its possible the beaver are living in the dam most likely in the bank near the end of the dam.  If you don't want to get rid of them yourself and don't want to pay to get rid of them you could wait until fall again and find a fur trapper they may trap them for free.

Karson

[XeonPony]

http://www.healthlinkbc.ca/healthfiles/hfile10.stm < Giardia (Beaver fever) can be filtered out mechanicaly at 1 micron & smaller (I use a .3 Silver-Ceramic filter).

If you catch it move the fridge, TV, and bed into the bath room as you will be geting to know the porcelin throne very well!

Another stealthy way is a good bow, get practicing!

[greenkarson]

i'v uploaded a pic to show you the best way to live with beavers.

[Lowhead]

I have a compound bow but just target practice arrows.  I think I'll have to visit the archery store.

Thanks for the suggestions Chris.  You've given me confidence to hook it into the MX without vaporizing my array or charge controller.  I'll run it open circuit and measure the voltage first.  I actually just bought a new rectifier so I'm not worried about blowing out the one that's in there.   During the extreme flooding we had here a month or so ago it got wet and the wire connections are now turning green so I was going to swap it out anyways.  It wasn't expensive from ES&D and I'm pretty sure if I had to I could get another at the alternator repair shop.  I think it's a Ford part.  So if I understand this right I need to adjust the magnet gap for the highest voltage (but still less than the 140V max of the MX60 when open circuit?).  That's a great idea to re-visit the Delta/Wye connections.  ES&D set it at the factory for a 48V system which probably isn't optimal for use with the MX.  Running at 75 volts for 1/2 the day and 90V the rest will be a big improvement.  If I remember right I measured 54 volts at the PMA when I first set it up.  My original plan (when I thought I could get more wire for cheap) was to add a 3rd set of 6 wires so that I could run 3 phase AC back to the house and rectify there.  This way is cheaper and easier.

I believe it is the same alternator as the stream engine.  I've double clamped the draft tube to the turbine housing and checked for leaks.  Since this unit works with mostly suction head it's important there are none and I'm pretty sure I've eliminated them.  I set the magnet gap back in December when it was freezing out (and I had a cast on my hand at the time) so I know it isn't optimal right now.  That's one thing I know I need to take care of - as soon as I get rid of the beavers.

Andy

[hydrosun]

Andy
You want to adjust the magnets and wire connections to have the open circuit voltage as high as you can get up to 180 volts.   The solar panels will clamp it to about 90 volts to protect the MX-60. When connected to the MX-60, it will slow the rpm and voltage to about half. The reason I worry about the diodes is the voltage can spike higher than the steady voltage and short the diodes to ground. I've had that happen on Harris hydro when the wire was accidentally broken.  So it might be simpler to just hook it up to the MX-60 adjust the magnet closest to the stator, and see what voltage the MX-60 chooses. If it is in the 80 to 90 volt range you're done.  Or if the night time watts is higher than what you are getting now.

 If you measured 54 volts at the turbine and 52 at the battery then you won't gain much from going to a higher voltage. Is that correct?
Chris

[Lowhead]

Thanks.  The 54 volts is from memory so I have to go out and measure it again this weekend.  Since I'm running at about 1/2 the power, I expect my losses to be higher when I get it adjusted to the 900 watts I should have with 9.5 feet of head.  I really need to install a permanent ammeter at both the turbine and the house and start logging my readings.

Andy

[Ungrounded Lightning Rod]

My problem is I don't own the pond so I can't extend any pipe into it.

Have you asked whomever owns the pond for permission?  Or maybe offered a few bucks a year to rent the right to do so?  (You could also promise to pull it back out if it causes a problem and/or if/when the beavers leave.

  The pond is very shallow - only about 3 at its deepest.  I'd have to extend the pipe about 50 feet just to get it 3 feet underwater.

How about extending it just a few feet and taking advantage of the beavers' lower interest in clogging up leaks in the body, rather than the edge, of their pond?

How about extending it just a bit, widening its inlet opening, and putting a fence around and over it, so the sound is mostly at the dam itself - and let them pile branches on the dam while they leave the inlet alone or pile a few on the fencing.

[ruddycrazy]

If the beavers want to dam let em go just extend your pipe further upstream, like ULR said was good advise, ask the land owner. Then agian if you do have real cold winters beaver pelts would make for a good pair of slippers.....

[TomW]

If the beavers want to dam let em go just extend your pipe further upstream, like ULR said was good advise, ask the land owner. Then agian if you do have real cold winters beaver pelts would make for a good pair of slippers.....

I "think" he said it was government owned?

If so, good luck getting permission.

Tom

[Lowhead]

Yes, the pond is owned by the MBTA (Massachusetts Bay Transportation Authority).  They don't actually want to own it - especially since their half of the dam needs work and they consider it a liability.  I'm trying to buy it but they have to put it out for public auction or give it away to the town and it's been dragging on for a couple of years.  I'm not willing to pay more than a few token $'s for it.

[DamonHD]

Well, they might be *more* prepared to give you an easement or whatever the correct legal leeway would be, if they see you making renewables and trying to avoid killing wildlife unnecessarily, ie that you are trying to DoTheRightThing(TM).

Rgds

Damon

[Ungrounded Lightning Rod]

Yes, the pond is owned by the MBTA (Massachusetts Bay Transportation Authority).  They don't actually want to own it - especially since their half of the dam needs work and they consider it a liability.  I'm trying to buy it but they have to put it out for public auction or give it away to the town and it's been dragging on for a couple of years.  I'm not willing to pay more than a few token $'s for it.

Bureaucrats.  Hmmm...

Meanwhile, there are issues with the beavers.  You might want to contact whatever department in your area is in charge of animal-borne contagious diseases.  (Here in CA it's called "vector control".)  Thanks to Giardia they can light a fire under the MBTA to do something about the beavers, if they can't deal with it themselves.

Then there's the issue of possible dam breakage and their liability for it, especially if they haven't been maintaining the dam.  Ought to be a department in charge of that, also.  Likely the transit agency will be even less interested in doing the repair work given the current economy.  Selling the property will help that twice - by unloading the maintenance issues and bringing in some bux.

I'd probably start with bringing the dam maintenance cost and risk issues up with the bureaucrat who's sitting on the paperwork for the bidding process.  Just as a buddy and being extra careful not to make any threats or sound like I'm offering a bribe.  (Maybe they already got that idea and that's why it's going slow, trying to encourage you to pony up?  B-b )  Then I'd go to vector control and ask them to check out the beavers.

Pinging the drainage-issues agency might help by giving them an order to get the maintenance done, but it probably has too much risk that they'll tell you to pull out your turbine.

[ghurd]

"Massachusetts"?  To me that means fairly crowded and overly controlled (the people, not the beaver).
Maybe my "magnet retaining device" would not be exactly suitable under the circumstances.
http://www.otherpower.com/images/scimages/2050/PICT0404.JPG

However, like ULR said, if they are living in the dam, they will weaken it.
Under "fairly crowded", that could cause down stream issues.
As could the Giardia.

Damon- the things are like 70 pound rats that breed like rabbits.
A friend's lawn goes up to Girard Lake (AKA Upper Liberty Lake).  He was on the midnight shift.
Went to work and all was fine.
Got home from work and a 12~14" dia, 30'(?) tall Poplar was gone.  Everything but some leaves and the stump was missing.
It was about at the center of this link, which happens to be taken when the lake drained due to dam issues.
http://maps.google.com/?ie=UTF8&ll=41.207954,-80.701586&spn=0.000999,0.002411&t=h&z=19

The only people who want to avoid killing this particular wildlife unnecessarily, are the people who do not have to directly deal with them.
G-

[greenkarson]

Another point about nuisance beaver here in Ontario.  May be different where you are.  Is that if the beaver are actually living within your property boundaries but go up or down stream and do property damage.  You can be held liable for not dealing with the nuisance animals on your property.   May not be the same where you are.  But something to consider anyways.

Karson

[Lowhead]

The town/county line runs right through the center of the river and pond.  I own the southern half of the dam and the "T" owns the northern half but they own the whole pond - in fact they own the river for 1/2 mile upstream.  This goes back to 1798 when the Governor of MA granted the mill rights every 1/2 mile along the river.  The beavers are living in the dam on my half so the "T" won't be interested in any maintenance issues on my side.  The beavers can't possibly raise the level of the pond any since there is a wide spillway that controls the level and they aren't trying to dam that - just my little 3 foot wide culvert.  I can probably get permission from the board of health regarding the giardia but it would be a stretch.  It isn't a pond that anyone swims in or uses for their water supply.  It's only 3 acres and 3 feet deep.  I assume it used to be deeper but has silted up in the 90 years since the mill went out of business.  I tried to get some sort of easement or power sharing going (FERC stuff) with the T but they have bigger problems to deal with and it just isn't a priority, even though the river could power their parking lights and probably a few car charging stations.  The local library had a copy of the auction brochure from when the mill went bust.  There was a 15 inch Leffel turbine driving an 80Kw Westinghouse generator.  The mill had closer to 20 feet of head with a long tailrace that has since been filled in.

I took the turbine out last weekend to replace the rectifier and rewire it as Chris suggested.  It turns out it was already set up that way.  There didn't seem to be any recent beaver activity.  It might be wishful thinking that they got tired of my disassembling all their work each morning and moved on.  I'll be putting it back in this weekend and moving the feed over to the MX60.    The hydro feeds through it's own 20 amp breaker.  Any reason why I shouldn't feed the output of that right to the PV+ busbar in the Midnight Epanel (before the GFI breaker)?

Andy