Wash out once the beaver are gone?

My experience - which is admittedly limited - is yes.
The creeks rise up with flood waters and the dam is gone!
I keep and eye on that spot as I have seen a new pair of beavers return to within 25 - 100yds and rebuild.

Disintegration takes time. You can help them out a little.

Most will erode but I had a few that lasted years without maintenance . They had trees growing out of them. Landowner finally blew them with dynamite but the beaver build new dams within a few feet of the originals.

Depends what kind of creek and water flows and pressure etc. If just slow water dams, they can last decades after the beaver are removed. One on my land has been there over 30 years. Minor creek, makes a nice pond. So I left it.

This ^^ was my normal practice.

This is five days after. You can see where the water was on the tree. I did nothing except remove the beaver.

Depends on construction and the body of water. Areas that are more hilly and push a lot of water during flash floods disappear faster. Areas that have clay based soil, the dams may as well be made of concrete.

This!

I've seen fresh stick dams in narrow creeks get popped like a champagne cork in a good rain and a can show you clay dams that haven't seen a beaver in years. I bet the one a saw made of piled rip rap is still there as well.

Since the bulk of our terrain is flat to rolling and our soils are fine grained clay the typical dam here is rarely taller than hip high outside the main channels and are long meandering constructions more often than not made up of swamp grasses and mud with the sticks and logs reserved for the channels and big holes. Over time our fine grained (lots of mica) clay encases these low dams and they become permanent even if breached.

Here,old dams that are not maintained for a few years can open up if there is sufficient water flow.Often they will just percolate the water thru.The dam will remain-grassy with willow etc growing on it but wont hold much water for long.The old pond becomes a beaver meadow with lots of standing dead chicots which are important to many species of wildlife.
In areas that are untrapped,many of these dead areas will be seen in succession as the beaver move upstream as feed is depleted.These areas cannot sustain a new beaver colony for quite a few years.Sometimes a beaver or two will move in for a while in summer and do some work on the dam,but they usually leave by September,or get picked off by wolves because they need to venture too far on land to collect suitable feed for winter.

Boco, are chicots, Kentucky Coffee trees? Kentucky Coffee trees get a wide pod, with very hard seeds, that are very, very hard to crack, that are used as a coffee substitute.

Keith

I doubt it, Kentucky coffee tree is only found from southern michigan down to northeast Oklahoma

Chicots- https://www.workplacesafetynorth.ca...rces/Forestry_chicot_safety_brochure.pdf

Loggers: Beware the chicot danger zone- https://www.workplacesafetynorth.ca/news/news-post/loggers-beware-chicot-danger-zone

Chicot is an Indian word for "just one more thing in the beaver swamp trying to kill me"

As stated above, depends on the soil type, well packed clay types being the dams most resistant to increased water flow especially if they have been baked in the sun several weeks. Another factor is the amount and type of vegetation in the mix. Green cut sticks & limbs peeled and imbedded in the dam seem to last forever. Moss and other water based vegetation usually begins to decompose fairly quickly here in the South. In this country, the greatest threat to dam and lodge stability is damage by feral hogs in search of food as water levels recede during hot, dry summer months. By the following winter they are usually built back, unless the area's beaver population has been greatly reduced, especially downstream, by predation or ADC trappers. Summer predation here is usually done by alligators, bobcats and coyotes, in that order. Water levels are usually lower at that time in creeks, rivers, ponds and lakes, and the beaver kits are much more vulnerable both in the water and as they begin following the adults on shore to start learning to forage on land. I don't know of any carnivore that doesn't relish beaver meat. Beaver carcasses are my all time favorite for predator draw stations. I just have to hide them from turkey vultures, Mexican buzzards(the ones with grey/bluish heads), and sometimes bald eagles. Since I set approaching trails with snares, incidental by-catch problems are fairly uncommon.