Small Dam & Micro-Hydro Building

[Eddie]

Not much sediment here. Big holes fill up with limestone gravel, and you harvest it with the backhoe in dry years. It's a renewable resource.

The swimming hole LD mentioned? I call it Gene's Hole after the guy I bought the stead from. It is a swimming hole because he cleaned it out periodically.

That's it in the first attachment.

The second attachment is the low water bridge Gene built. More environmental impact from that than my dam.

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[Eddie]

Second attachment didn't upload. Let me try again.

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[RE]

Not much sediment here. Big holes fill up with limestone gravel, and you harvest it with the backhoe in dry years. It's a renewable resource.

The swimming hole LD mentioned? I call it Gene's Hole after the guy I bought the stead from. It is a swimming hole because he cleaned it out periodically.

That's it in the first attachment.

The second attachment is the low water bridge Gene built. More environmental impact from that than my dam.

I only see 1 attachment.

RE

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[Eddie]

My DSL sucks.

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[Eddie]

Very muddy Mangalitsas.

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[RE]

Second attachment didn't upload. Let me try again.

We need to replace that low water bridge with a Suspension Bridge. 

I held Bridge Building Model competitions many times in my teaching years.  I've always wanted to scale up to around this size.  We built big enough ones to run RC Carz over small creeks.

Here's a Wheel Chair or Ewz size one.

One sturdy enough for an SUV would be a great challenge! 

RE

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[Eddie]

Another shot of Gene's Hole.

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[Farmer McGregor]

Very muddy Mangalitsas.

Happy as pigs in slop!

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[Farmer McGregor]

Another shot of Gene's Hole.

Nice puddle!
I love puddles.
Water is so awesome and precious.
It's greening up there. Nice.

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[Eddie]

Here's a video shot of the spot I want to dam.

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[Eddie]

Spring is here.

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[Eddie]

Last but not least, the Pig Palace. (Drapes optional).

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[RE]

Here's a video shot of the spot I want to dam.

Looks GREAT with all that water running! 

RE

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[RE]

I am starting a new thread specifically for this topic.  If it's OK with Eddie, I will split the posts off from his Toothstead thread related to this topic and merge them into this topic.

First the video.

<a href="http://www.youtube.com/v/fMGkwBBh7_I" target="_blank" class="new_win">http://www.youtube.com/v/fMGkwBBh7_I</a>

OK, after viewing Eddie's brief video, I see difficulties but also have a tentative plan of action.

First difficulty is the VOLUME of water currently moving through the proposed location and the speed at which it is currently moving.  This will make any construction very difficult.  But, as we know, the water there doesn't ALWAYS come in such volume so fast, so you need to wait for a time with low water to do the main construction.  Ideally of course would be full DROUGHT when nothing is running at all, as was the case when we had the first Convocation in 2014.  Then you could do all your construction without worrying about what to do with the water during construction.

BUT, you never know exactly when that moment will come?  So unless you have all your materials on hand and prepared and ready for the day or days that the creek runs dry, and then get out there and get it done PDQ before another Atmospheric River shows up and dumps 10" of rain in East Texas, this construction plan doesn't work.

So, you must plan for at least some water flowing during construction, and figure out what to do with that water.  Following is a Plan of Action I think works.  I am ready to be hammered with the usual Diner Negative Waves on this. lol.

Before constructing the main, real Dam, about 5-10' upstream from it you build a temporary sandbag dam.  Around this temp dam you create/dig a channel which will divert the water that is flowing around your actual permanent dam construction site.

Once your dried out permanent site is ready, now you begin construction of this Dam.  Eddie already said he doesn't want a big Earthen dam, so if it to be done with Concrete, I don't see the bagged concrete working here, so wooden or foam forms will have to be used and the mixed concrete poured into those forms.  I think a Gate should be incorporated into that structure.  In times of High water, it would blow any sediment down river (although Eddie says there is not much sediment to worry about).  In low water times, it would keep steady water moving down river.

The bigger problem I think are the High Water periods, given the current volume of water moving through this channel and the speed it is moving.  The Spillway you build next to the Dam itself has to be able to handle that amount of flow rate so the dam itself does not get over-topped.  Even at the flow rate I am looking at here, that is a pretty big spillway, and it has to be all reinforced concrete, or it's going to fail with enough flow rate.  I think in the big rainstorms that TX has been getting lately, this might even only be half what comes down that creek in a Big One.  One Big One, and down goes the dam, a lot of money, a lot of labor, and maybe damage downstream to neighbors when it fails, meaning a lawsuit from somebody.

The spillway HAS to be built to accommodate the absolute MAX you think is within reason.  Could you get a week of torrential rains?  These days, yes you could.  The dam has to be built to withstand that, it cannot be allowed to over-top.

The Dam itself can be built a few ways, but it's not the main issue.  The main issue is being able to handle BOTH periods of High Water and Low Water.  We do not live in a consistent environment anymore.  You need to plan for the extreme events.

RE

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[Eddie]

Good points.

I expect the water diversion issue will be a non issue at some point, we'll have a seriously dry late summer and fall that will dry the creek to a trickle that won't interfere much.

I think it's better to build a dam that's low and strong and bulletproof that it is to get fancy and install a gate, which really won't do much in full flood anyway. It isn't unusual to have full size live trees get washed out of the banks of my creek and swept away in a flood. I've seen it. No gate will hold up to that.

The dams I've seen that last are just long, low, straight check-dams.

I wish I could estimate the flow through there right now. I'd like to know, but the turbine people talk about filling up buckets, which is not going to work. When you don't have a lot of head, flow becomes crucially important for power generation.

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