A box in the woods?

[Stash]

Came across an unexpected sight along Sawyer River Trail a few weeks ago. A fairly new looking box suspended from galvanized pipes above a frozen stream. Maybe 16" x 16" by 16'. Looks like some sort of screen or fencing on the bottom.

Picture here: Box in the woods

I'm wondering if it is some sort of beaver trap? The picture is taken from a bridge on the trail/road just upstream from the box. On the other side of the bridge and a bit further upstream is a very large beaver dam that, if it ever lets go, would take out the bridge and road. Possible they want to relocate the beavers and remove the dam? Wouldn't think that would in a wilderness area.

Any ideas?

 

[RollingRock]

I've seen similar construction around Cone Pond by the Hubbard Brook Experimental Forest. I'm thinking this is some sort of study for water quality and acid rain.

 

[Spaderman]

Box in the woods

It's for the beaver dam. In order to maintain some water flow downstream, they build these boxes. They are set up on existing dams. The box extends far enough upstream that the beaver cannot "dam it" with sticks thus allowing water to flow thru the box so the downstream habitats aren't disturbed by the lack of water from the beaver building the dam. It's also part of flood control as the water level is kept from getting too high & flood areas out such as hiking trails. However, if you have a smart beaver, he'll figure it out & dam the upstream end. In order to avoid this, you may see a heavy wire mesh/re-bar type box around the upstream box to keep it clear of sticks from the beaver.

Now you know probably more than you need to regarding the box. In case you're wondering, no, I don't work for the Parks Dept. or Forestry Dept.. I've shared a pond next to my house with a beaver or two for the past 20 yrs. & they've always peaked my interest. For them, "It's one dam project after another!"

Spaderman

 

[Stan]

Thank you for that information Spaderman. There are a couple near the trailhead of Livermore Trail in Waterville Valley. I thought they might be for something like that or perhaps to keep debris from clogging up the culverts. I didn't see any sign of beaver in the area.

 

[SAR-EMT40]

It's for the beaver dam. In order to maintain some water flow downstream, they build these boxes. They are set up on existing dams. The box extends far enough upstream that the beaver cannot "dam it" with sticks thus allowing water to flow thru the box so the downstream habitats aren't disturbed by the lack of water from the beaver building the dam. It's also part of flood control as the water level is kept from getting too high & flood areas out such as hiking trails. However, if you have a smart beaver, he'll figure it out & dam the upstream end. In order to avoid this, you may see a heavy wire mesh/re-bar type box around the upstream box to keep it clear of sticks from the beaver.

Now you know probably more than you need to regarding the box. In case you're wondering, no, I don't work for the Parks Dept. or Forestry Dept.. I've shared a pond next to my house with a beaver or two for the past 20 yrs. & they've always peaked my interest. For them, "It's one dam project after another!"

Spaderman

But, the end thats visible is closed, so how does it allow water to flow? Is the bottom missing?

Keith

 

[Stash]

But, the end thats visible is closed, so how does it allow water to flow? Is the bottom missing?

Keith

If you look on the bottom you'll see what looks like wire fencing. I believe at least part the bottom is open except fort the fencing. Spaderman's explanation certainly makes sense to me.

 

[SAR-EMT40]

If you look on the bottom you'll see what looks like wire fencing. I believe at least part the bottom is open except fort the fencing. Spaderman's explanation certainly makes sense to me.

It certainly did to me also except I couldn't see how the water would flow. I get it now. Pretty cool.

Thanks,
Keith

 

[Little Rickie]

I think as long as it leaks water around/through the dam it serves the purpose. It the flow was obvious the beavers would block it.

 

[psmart]

This is also know as an "beaver pipe" or "beaver baffler". Beavers will attempt to block any palce in their dam they sense flowing water. With a beaver pipe, the flow comes up through the screened area at the bottom of the pipe where they cannot block it with sticks and mud.

BTW, This area is not in Wilderness, so it's subject to normal management practices for beaver.