# Tag Info

19

Once a dam has been constructed in a river, the natural flow of water will be disrupted. You correctly state that initially there will be a period required for the dam to fill. Until then, little of no water will flow beyond the dam. Dams are created for one or more of three reasons: To supply potable water to a population of humans for domestic or ...

14

You're correct that simply putting a dam in place, once its lake is filled, doesn't change the average flow downstream by more than a few percent (those few percent can be lost to increased evaporation). However, Many dam systems are used to abstract water from the river for irrigation and other uses, sometimes on a very large scale. This does reduce the ...

7

My first thought would be to use Manning equation as an approximation. It does not take into account the effect of a dam burst providing excess water and immediate flooding, although for larger scales (in terms of river reach) this is likely less important. Detailed hydrologic models may not be the right answer by the way, especially for the tradeoff of ...

4

The .06 microseconds figure doesn't sound accurate The moment of inertia for a solid sphere is $$I = \frac{2mr^2}{5},$$ where $m$ is the mass of the sphere and $r$ is its radius. Applied to the Earth, this gives us $$I = \frac{2\cdot5.972\times10^{24} \text{ kg} (6371000 \text{ m})^2}{5} = 9.70\times10^{37} \text{ km-m}^2.$$ A simplified estimate of moment ...

3

Okay have a look at this article it may be some use, it's the Journal of GeoEngineering, Vol. 8, No. 1 April 2013 Pgs 27-32 so you may be able to get a hard copy if the link fails, it talks about clay core dams and seepage calculations thereof, including phreatic pathway estimation. If I remember correctly rock fill in earth dams is treated as earth for the ...

3

You need to calculate the change in the moment of inertia of the Earth and use conservation of angular momentum (the rotation period is proportional to the moment of inertia). Most of the water will ultimately come from the oceans, effectively removing a thin layer of water. Jerry Mitrovica discusses this effect (in reverse) in a Nautilus interview: Is ...

1

Obviously removing the silt will increase the erosion along the banks of the pond(the neighbors will probably not like this). It sounds to me like this pond is badly constructed if the erosion is eating away peoples property. the best option might be to fill in the area and use it for something else,a park-playground or simply let it become a wetland with ...

1

Cut a notch into the dam so the water drains to the level you want. The marsh will shrink to a smaller size.

1

That is what lakes and ponds do , fill with silt. Serious earth moving equipment is needed to slow Mother Nature. Our community has recently removed some silt with draglines, bulldozers , trucks , etc. I don't know the cost but certainly significant . They concentrated on certain areas to facilitate flow as we have a dammed stream that made roughly a 300 and ...

1

" Who's studied the glacial dam breaking South and having cleared the Hudson River valley, forming the Verrazano Narrows, NY Harbor, Staten and Long Island, and washing through to the Atlantic Continental Shelf?" There's a USGS group at Woods Hole that's done a bit of work on this back in 2004: A catastrophic meltwater flood event and the formation of the ...

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