Leave it to beaver - Page 4 - PeachParts Mercedes-Benz Forum

Zeus · #46 04-16-2008, 10:19 AM

Lol, saw this on the msn.ca home page today...your problem could be, er, bigger Bot...

http://technology.sympatico.msn.cbc.ca/Big+dam+Alberta+beavers+build+850metre+barrier/News/ContentPosting.aspx?isfa=1&newsitemid=beaver-park&feedname=CBC-TECH-SCIENCE&show=False&number=0&showbyline=True&subtitle=&detect=&abc=abc&date=True

Jordan G · #47 04-16-2008, 10:21 AM

Quote:

Originally Posted by Botnst

Mean is 120 cfs, annual high is 400. We get about 50 inches of rain/year, mostly in late spring through summer. I have seen evapotranspiration tables but damned if I know where.

Drainage area is probably 800 acres or more of very deep, sandy soil so rain penetrates very quickly. Most of the 800 acres is in timber, though there are a few small farms, pastures, and gravel roads. There are also several farm ponds on intermittent tributaries.

Work your magic on that!

I'm building your model in HY-8 right now......but I'll need a little more info.

Do you know the approximate ht of dam, top width of dam and bottom/top width of the rest of the channel? I was orginally thinking a corrugated metal pipe - but WVO makes a good point - you'll need to push the thing thru the the damned dam - so maybe smaller diameter steel pipe (capped off when driving?) is better, as it would be tough to drive a large diameter CMP.

And forgive me for not being sensitive to Mr. Beaver.....but is the intent to discharge ALL of the water immediately.....or slowly so they relocate?

I'm interested to hear how this works out.....you'd think they'd just plug the silly pipe up but who knows.....

Chad300tdt · #48 04-16-2008, 10:26 AM

Here's a link with a few dam ideas.

http://www.gov.ns.ca/natr/wildlife/Nuisance/beavers.htm

t walgamuth · #49 04-16-2008, 10:30 AM

They don't understand pipes!

Tom W

Chad300tdt · #50 04-16-2008, 10:34 AM

Here's a snippet from the above link that I didn't know.

"This system (pipes) works on the principle that beaver build dams in response to the sound of running water. They may hear the water going through this pipe but cannot locate the leak source."

Jordan G · #51 04-16-2008, 10:37 AM

^^^ that answers my question.....it said in there that beavers operate under the sound of falling water for discernment on leaks......so I wouldn't put the pipes on the channel invert....but up higher on the dam so you have some splashing downstream.

Reading b/w the lines....I think I'd go with PVC too, so you can perforate the upstream end too and cap the end - making a built-in strainer and more difficult to plug IF they figure it out.

Building the hydraulic model is fun though - but golly, you'd probably be ok with 3 or 4 8" dia. PVC pipes sticking out 5' from the upstream face of the dam - spaced evenly across the width of the dam?

It won't pass of ton of flow being perforated but it's probably enough to piss them off.

Of course, how far does a beaver relocate too? Does he just move 100' upstream?

Jordan G · #52 04-16-2008, 10:38 AM

Quote:

Originally Posted by t walgamuth

They don't understand pipes!

Tom W

Those stupid beavers.

Having said that, I just took my professional engineers exam and I'm not sure I understand pipes either.

Kpmurphy · #53 04-16-2008, 10:43 AM

how about some pictures of the dam
that would be cool

WVOtoGO · #54 04-16-2008, 11:15 AM

Quote:

Originally Posted by Jordan G

I'm building your model in HY-8 right now......but I'll need a little more info.

Do you know the approximate ht of dam, top width of dam and bottom/top width of the rest of the channel? I was orginally thinking a corrugated metal pipe - but WVO makes a good point - you'll need to push the thing thru the the damned dam - so maybe smaller diameter steel pipe (capped off when driving?) is better, as it would be tough to drive a large diameter CMP.

And forgive me for not being sensitive to Mr. Beaver.....but is the intent to discharge ALL of the water immediately.....or slowly so they relocate?

I'm interested to hear how this works out.....you'd think they'd just plug the silly pipe up but who knows.....

We never found the need to cap them.
(That would just mean that someone has to get rather wet to pull the cap off.)
Have someone hold it at the angle you think it should be and PUSH.
If it dead centers a big log and looks like it may bend the pipe, just pull it out a bit and try another angle/location. This didn't happen too often though.

BTW - You'll know it when you've pushed far enough.

Botnst · #55 04-16-2008, 12:42 PM

Quote:

Originally Posted by Jordan G

I'm building your model in HY-8 right now......but I'll need a little more info.

Do you know the approximate ht of dam, top width of dam and bottom/top width of the rest of the channel? I was orginally thinking a corrugated metal pipe - but WVO makes a good point - you'll need to push the thing thru the the damned dam - so maybe smaller diameter steel pipe (capped off when driving?) is better, as it would be tough to drive a large diameter CMP.

And forgive me for not being sensitive to Mr. Beaver.....but is the intent to discharge ALL of the water immediately.....or slowly so they relocate?

I'm interested to hear how this works out.....you'd think they'd just plug the silly pipe up but who knows.....

The dam is about 3 ft tall, 4 ft at the base with a 1 ft top. The sides are unequal with nearly vertical on the outer face and gently sloping on the inner. The material is about 3/4 mud and the rest vegetative matter varying from fibrous vegetation to 6" stems.

The bottom is nearly flat -- it's a floodplain. However, the surface is probably more than half-full of rooted & floating aquatics and the dead & dying timber. Also, the dam itself is extremely sinuous and so the dam length is anybody's guess -- maybe 400 ft? The total area of the beaver pond is probably 3 - 4 acres with a slope from dam to upper part of pond of maybe 300 ft.

The intent is to save the timber, f**k the beavers. I was gonna shoot the little bastids -- a relocation is comparatively merciful.

Mistress · #56 04-16-2008, 12:45 PM

The Army Corp of Engineers should start consulting beavers when they have to build and or inspect damns and levees.

Jordan G · #57 04-16-2008, 01:56 PM

Quote:

Originally Posted by Botnst

The dam is about 3 ft tall, 4 ft at the base with a 1 ft top. The sides are unequal with nearly vertical on the outer face and gently sloping on the inner. The material is about 3/4 mud and the rest vegetative matter varying from fibrous vegetation to 6" stems.

The bottom is nearly flat -- it's a floodplain. However, the surface is probably more than half-full of rooted & floating aquatics and the dead & dying timber. Also, the dam itself is extremely sinuous and so the dam length is anybody's guess -- maybe 400 ft? The total area of the beaver pond is probably 3 - 4 acres with a slope from dam to upper part of pond of maybe 300 ft.

The intent is to save the timber, f**k the beavers. I was gonna shoot the little bastids -- a relocation is comparatively merciful.

Gotcha, wow, that's much bigger than I was foolishly picturing (I was thinking a 20' wide dam or so) - and HY8 might not be the best model for this....but playing around with the numbers for a 120 cfs storm discharge:

8" dia PVC pipes, set 1'0" above the bottom of the dam and spaced every 5' would drop the pond surface elevation around a foot and pass the mean storm event right on through.

Having said that - driving in 80 pipes in mud sounds like a colossal pain in the a$$ but that's a pretty decent watershed, over a square mile.

I obviously reserve the right to be horrifically wrong.

WVO - comparatively speaking - how damn big was your dam? It's tough to argue with real-world applications.

Botnst · #58 04-16-2008, 03:51 PM

Remember that the beaver's dam is not efficient from a human standpoint. The sucker leaks along it's entire length and when a slug of water from a thunderstorm hits, the dam is overtopped along it's whole length. To maintain it's integrity the whole beaver family works on it 24/7, though mostly at night. Also, the beavers are constantly thickening and elevating it. So over time, the dam will flood a larger and deeper area. In a flat floodplain such as I am describing the beavers often build networks of dams cascading into each other with enclosed pools at slightly different elevations. So it is, no question, a multivariate problem.

I think your solution isn't too far off, though completely unrealistic. I'd rather sit in a tree at night with a .22 than dig that many trenches with a shovel and pick-axe.

I assume that the number of pipes decreases with the pipe diameter as some sort of power function. What if I went to a 10" or 12" pipe? How about if we assumed that the dam is only 75% efficient? 50% efficient?

How much do I have to pay you for this? I might have to change my screen name.

B

Jordan G · #59 04-16-2008, 04:31 PM

Quote:

Originally Posted by Botnst

Remember that the beaver's dam is not efficient from a human standpoint. The sucker leaks along it's entire length and when a slug of water from a thunderstorm hits, the dam is overtopped along it's whole length. To maintain it's integrity the whole beaver family works on it 24/7, though mostly at night. Also, the beavers are constantly thickening and elevating it. So over time, the dam will flood a larger and deeper area. In a flat floodplain such as I am describing the beavers often build networks of dams cascading into each other with enclosed pools at slightly different elevations. So it is, no question, a multivariate problem.

I think your solution isn't too far off, though completely unrealistic. I'd rather sit in a tree at night with a .22 than dig that many trenches with a shovel and pick-axe.

I assume that the number of pipes decreases with the pipe diameter as some sort of power function. What if I went to a 10" or 12" pipe? How about if we assumed that the dam is only 75% efficient? 50% efficient?

How much do I have to pay you for this? I might have to change my screen name.

B

Yah - I had considered that (not in the numbers though). In the model, it's treating the dam like a concrete headwall - not some permeable, living thing. Sorry, I wasn't gonna break out the flownets to figure out the equipotential drops.

. I suppose we could just modify the discharge because it's almost like a base flow that could be taken out.

Absolutely - 12" makes a difference - you could get the same result with a pipe every 13-15' on center. Still a royal pain though. I just went with 8" because it's easier to work with and easy to obtain. Generally speaking - using manning's equation Q = (1.486/n )(A)(R^.67) (S^.5) so maybe not the gains you'd expect but still...

Frankly, if it were me - I think I'd put in 20 pipes, smoke a cigar and have Mrs. B. rub your back (Mrs. G in my case).

Or buy a laser scope and invite Howie over. No payment required for haphazard analysis.

Botnst · #60 04-16-2008, 05:30 PM

The laser solution is back on the table! $400 for the gun is far cheaper than PT & drugs.

I'm going back up in a month to break the dam again. This time I'll try inserting a half-dozen pipes (I think I broke the dam in 6 places previously).