Helpful Info. Dam building

[Silent Bob]

Since next weekend I am building a dam out at my lol..Shangra La...here are two PDF's on dams, that might be useful for developing your onsite water sources.

 

[flatheadlakeprepper]

Since next weekend I am building a dam out at my lol..Shangra La...here are two PDF's on dams, that might be useful for developing your onsite water sources.

Silent Bob.....thanks for posting the information. I did a quick review and it should be pointed out that this information regarding check dams is for low head, relatively small impoundment structures.

We tend to worry about and consider the potential for dam failure as the biggest cause of problems with small catchments. Although a dam failure can be the most catastrophic event that might threaten downgrading infrastructure or buildings, there is an often overlooked issue with dams and that is loss of capacity due to sediment deposition. Typical sediment loads for streams, creeks, rivers, etc. is highly variable, but is truly much greater than almost anyone imagines. On average, a good back of the envelop number is that within a decade, most personal catchment basins will have lost 25% of the originally available volume due to sediment deposition and 40-50% within 20 years. The result is that catchments are often undersized and lack sufficient volume to meet the intended goals and usage in very short order. Bottomline, if your designing for a specific volume of water to meet a need, two things should be considered. First, add a minimum of 25% to the desired volume and catchment size to offset the first decade's sedimentation. Second, consider upstream ways to intercept sediment that can be easily cleaned to minimize the amount of sediment available for transport into and deposition within the catchment. Just some ideas and things to consider. Hope it helps

 

[Brent S]

Silent Bob.....thanks for posting the information. I did a quick review and it should be pointed out that this information regarding check dams is for low head, relatively small impoundment structures.

We tend to worry about and consider the potential for dam failure as the biggest cause of problems with small catchments. Although a dam failure can be the most catastrophic event that might threaten downgrading infrastructure or buildings, there is an often overlooked issue with dams and that is loss of capacity due to sediment deposition. Typical sediment loads for streams, creeks, rivers, etc. is highly variable, but is truly much greater than almost anyone imagines. On average, a good back of the envelop number is that within a decade, most personal catchment basins will have lost 25% of the originally available volume due to sediment deposition and 40-50% within 20 years. The result is that catchments are often undersized and lack sufficient volume to meet the intended goals and usage in very short order. Bottomline, if your designing for a specific volume of water to meet a need, two things should be considered. First, add a minimum of 25% to the desired volume and catchment size to offset the first decade's sedimentation. Second, consider upstream ways to intercept sediment that can be easily cleaned to minimize the amount of sediment available for transport into and deposition within the catchment. Just some ideas and things to consider. Hope it helps

I have three bodies of water in a small creek on the front of my property that flow into each other. It took about 8yrs before the first one was filled with sediment, so your calculations are pretty accurate. I rented a backhoe recently to clean it out and hopefully will get another 8 to ten yrs. One of these days I'll put a wheel of some sort in it to run a car alternator just for fun.
I read an interesting article on the three gorges dam in china. Sediment removal is a 24/7 project. They said when they stopped the flow of water in that system there was a measurable wobble in the earth. That's one heck of a project.

 

[DrHenley]

I read an interesting article on the three gorges dam in china. Sediment removal is a 24/7 project. They said when they stopped the flow of water in that system there was a measurable wobble in the earth. That's one heck of a project.

From what I understand, the epidemic of copper thefts and shortages of copper for making bullets a few years ago were caused by the massive use of copper in building that dam.

 

[Brent S]

From what I understand, the epidemic of copper thefts and shortages of copper for making bullets a few years ago were caused by the massive use of copper in building that dam.

It also bought up most of the worlds raw materials for making steel and concrete. The prices of steel went up dramatically and never came completely back down. All I am sure of is I wouldn't want to live downstream from that resevouir.

 

[Clyde]

Since next weekend I am building a dam out at my lol..Shangra La...here are two PDF's on dams, that might be useful for developing your onsite water sources.

I can't build a damn thing!

 

[flatheadlakeprepper]

Ok. Since dam building and sediment deposition are topics I actually know a great deal about, I thought it might be beneficial to post some ideas on various aspects of reducing the sediment deposition problem. I could post the information within this thread or I could start a new thread. Not sure which would be the best to do. Any suggestions? The problems of in channel sediment loading and the bigger problem for the dam builder is loss of sediment transport capability (sediment deposition) are affected by the size of the channel (flow or discharge), the terrain, the driving runoff event, and the vegetative cover within the drainage basin. Each of these could have its own prescription or remedy and could warrant its own post or thread. Again, any suggestions or requests?

 

[Brent S]

Since next weekend I am building a dam out at my lol..Shangra La...here are two PDF's on dams, that might be useful for developing your onsite water sources.

what kind of dam are you going to do? When I first came to Ga. you could make one 24.9 ft deep without a permit. Now, if you restrict your pee stream they want a permit and ecological study!

 

[Silent Bob]

what kind of dam are you going to do? When I first came to Ga. you could make one 24.9 ft deep without a permit. Now, if you restrict your pee stream they want a permit and ecological study!

Brent,

As you know from my past talks, our lovely little city made the national news. Right now I know of no other municipality which is dumping gray water (reuse program) back and mixing it back into the fresh water. The next phase is to run the pipe right back into our main water reservoir lake. We've done just about everything to help conserve water, which includes extreme water conservation and we have a reverse osmosis plant that can pretty much do everything, an investment that will pay in later years, begun to work with the city of Dallas to evaluate building a larger man-made reservoir that will be three times the size of the two existing lakes that can serve not only our MSA, but the growing metroplex. The Corps of Engineers have begun working with the water authorities on how best to deal with the environmental impact studies and while it will be at least 10 years before we see a return, its the right step for the community and beyond. I've been a pro-advocate of some other crazy measures, so met some really smart people in the water business. While striking up the conversations, I met a great guy who helped designs nationally these reservoirs and is a lead advisor to many state water conservation boards (ironically one for the state of Colorado), so he was immeasurable helpful not only in helping design my ideas, but helped me push through the bureaucratic mess that most state laws either prevent or slow down growth in this area.

On the BOL, the first phase was to construct the man-made pond which he helped designed and the second phase was building the dam, yes sediment consideration was evaluated when designing the dam. Since the majority of the pond is fed off during spring run off, we decided that we would risk the sediment issue for now...possibly at a later date, we will build something, but I wanted to take advantage of this year's run-off to help fill the pond, so that possibly later I could begin stocking it with state game-fishery approved fish. I've been working with the local fish-game warden on this issue too. Its a gamble for me, since I have little experience in this sector, so hopefully it will begin to develop and offer us some possibilities toward self-sufficiency later.

 

[Brent S]

Brent,

As you know from my past talks, our lovely little city made the national news. Right now I know of no other municipality which is dumping gray water (reuse program) back and mixing it back into the fresh water. The next phase is to run the pipe right back into our main water reservoir lake. We've done just about everything to help conserve water, which includes extreme water conservation and we have a reverse osmosis plant that can pretty much do everything, an investment that will pay in later years, begun to work with the city of Dallas to evaluate building a larger man-made reservoir that will be three times the size of the two existing lakes that can serve not only our MSA, but the growing metroplex. The Corps of Engineers have begun working with the water authorities on how best to deal with the environmental impact studies and while it will be at least 10 years before we see a return, its the right step for the community and beyond. I've been a pro-advocate of some other crazy measures, so met some really smart people in the water business. While striking up the conversations, I met a great guy who helped designs nationally these reservoirs and is a lead advisor to many state water conservation boards (ironically one for the state of Colorado), so he was immeasurable helpful not only in helping design my ideas, but helped me push through the bureaucratic mess that most state laws either prevent or slow down growth in this area.

On the BOL, the first phase was to construct the man-made pond which he helped designed and the second phase was building the dam, yes sediment consideration was evaluated when designing the dam. Since the majority of the pond is fed off during spring run off, we decided that we would risk the sediment issue for now...possibly at a later date, we will build something, but I wanted to take advantage of this year's run-off to help fill the pond, so that possibly later I could begin stocking it with state game-fishery approved fish. I've been working with the local fish-game warden on this issue too. Its a gamble for me, since I have little experience in this sector, so hopefully it will begin to develop and offer us some possibilities toward self-sufficiency later.

How big of a reservoir will it be? My neighbor dug out a giant hole in the fron creek, 12' deep and probably 100' square. He had a job locally that needed fill dirt, so he got paid to make a really nice pond. My ponds in the front start with a stream section about five ft wide and 60' long and five ft deep. That part catches most of the sediment, and then flows into a pond about 30x6o' which is about 6 ft deep. Then it crosses under the driveway and I have a small pond about 12' round, which I plan to raise brim in this spring. I wish I could do more with the large stream on the back of the property but don't own both sides and have a grumpy neighbor, so it stays natural.
I will say one thing for sure. You're on the right track. No matter where you go, water is the number one thing you will need, so incorporating it in the initial plan is wise. I hope you're feeling better friend, brent.