Suggestions to limit pond silting...

[ultrarunner]

A friend has a very small irrigation pond... maybe 10' by 30' and no more than 3' deep.

Last winter and every winter that has a lot of rain fills his pond with silt and then he has to physically dig it out...

It's only a problem in years with lots of rain.

I was thinking he needs to make an opening in the dam so in wet weather the silt can flow right on through...

In the summer... the flow from the spring is only a trickle so no problem with silting...

Would something like this even work?

 

[SandburRanch]

A friend has a very small irrigation pond... maybe 10' by 30' and no more than 3' deep.

Last winter and every winter that has a lot of rain fills his pond with silt and then he has to physically dig it out...

It's only a problem in years with lots of rain.

I was thinking he needs to make an opening in the dam so in wet weather the silt can flow right on through...

In the summer... the flow from the spring is only a trickle so no problem with silting...

Would something like this even work?

In most instances this falls back to the old saying that "an ounce of prevention is worth a pound of cure".

So rather than looking at the pond look up stream for ways to prevent the erosion. Without a picture of the situation it would be difficult to advise but in general, trees, shrubs and grasses are a must have. Your friends soil conservation service may be a good place to start.

 

[ultrarunner]

In most instances this falls back to the old saying that "an ounce of prevention is worth a pound of cure".

So rather than looking at the pond look up stream for ways to prevent the erosion. Without a picture of the situation it would be difficult to advise but in general, trees, shrubs and grasses are a must have. Your friends soil conservation service may be a good place to start.

There are several properties with storm culverts that flow in the direction of the pond... some years with low rain fall the water in non-existent...

They have a well near the pond put in 40 years ago down 130 feet... it will pump a huge volume for about 4 minutes and then it is like turning off a switch... 24 hours later he can get another 3 or 4 minutes...

To meet demands he stores water in three 1650 gallon tanks...

 

[powerpace]

Your pond should be bigger with a clay bottom if possible. This will hold water longer. It sounds like your depending on runoff for you water supply to the pond. A good pond would allow water seepage from the bottom to fill. This depends on the water table.
My pond has runoff in the winter and seepage in the summer. It only drops about a foot between winter and summer.
I did have to divert water that was bringing silt into the pond. It flows into a lower field instead of into the pond then into the field.
The pond is a quarter acre about six feet deep at the dam and overflow. Surrounded by grass and Pussywillows to prevent silting.
I do have some shallow ditches that flow into the pond that are gravel for the last dozen feet to prevent erosion.

 

[Hollow]

He can run a pipe through the bottom of the dam with a threaded elbow on the pond side and run a pipe up to the water level. Then once a year drain the pond and let a few big rains wash the silt through. With that much flow it shouldn't take long to fill the pond back up.

 

[ultrarunner]

I was thinking something 6 or 8" that can flow freely in wet weather...

This is in CA where it can be several months to half a year without significant rain...

Seems to only be a problem a couple of times a year when there is a real "Gully Washer"

 

[AGGIE00]

My pond, which is about an acre, has sand all around and upstrem of it. Water sheetflows into it across about 120ft and creates enormous gullys in one rain. We are in the process of building a bulkhead out of driven posts with rr ties behind. I will lay in filter fabric behind the rr ties to prevent undermining with the sand. this gives something for the water to spill over and have a deeper edge.

 

[Fossil Farm]

Depending on how much room he has, digging a small sediment basin upstream of his "pond" would help drop a fair amount of sediment before reaching his pond. His pond is now acting as a sediment basin and his downstream neighbors should be very appreciative. When water with sediment hits a "calm" area - his pond - it will drop out the sediment. If an additional calm area is added prior to his pond, the sediment will drop out there and he can monitor and clean out the area as needed. If possible it should be twice as long as wide and if he can put in a baffle or two (like a piece of steel or plywood) to force the water to take a longer path through the sediment basin it will be much more effective. Guess it just depends on how often he needs the water if it is worth putting in a sediment basin. Just be sure there are no underground utilities to cut before digging. Also, if the watershed above the pond is large, it will always be a problem. Typically for a 1 acre pond, more than 10 acres of ground area flowing into it can start to be a problem. If he does not own that land, then it is harder to control the quality of water flowing into the pond. A clay bottom or liner will help retain the water for a longer period of time as mentioned previously.

 

[jinman]

My pond, which is about an acre, has sand all around and upstrem of it. Water sheetflows into it across about 120ft and creates enormous gullys in one rain. We are in the process of building a bulkhead out of driven posts with rr ties behind. I will lay in filter fabric behind the rr ties to prevent undermining with the sand. this gives something for the water to spill over and have a deeper edge.

You know, I was thinking of almost exactly the same type structure to trap the silt before it gets to the pond.:thumbsup: However, if he gets enough silt to fill the pond, he's going to have that silt to contain no matter what. Essentially, what I'm saying is that he needs a catch pond for water and another upstream for silt (Fossil Farm's idea). If there are a lot of "upstreams" coming from several directions, then it gets really difficult. Anyway you look at it, if the silt happens, you end up having to haul silt. Certainly, structures that slow the flow will allow the silt to deposit before the pond. Anything that filters the flow will help. Getting the silt to deposit in a place that is more accessible than the pond may be the long-term solution. It's hard to say without pictures and elevations involved.