Liquidsquid: Those are some beautiful spots. I can see removal of gravel being an ongoing chore for me if I end up damming this thing up somehow.
Dg84s: I'd say we are in very similar scenarios with perhaps our geographic and geological differences being about the only ones. I do have some exposed bedrock in the creek bed but much of it is covered with gravel/silt/sand. My hopes were to clean this thing out with a mini backhoe FEL (which I can rent for about $250 for the weekend) and try to also get a little more width. I'm in the same boat as far as I don't want to invest thousands of dollars into this thing to only have to continue to invest more time and money constantly with no real hopes of it being sustainable, having to redo things every time it floods. I too am wanting to dam it up cheaply and effectively and just see what happens for a while and as you may have seen the guys have offered some great suggestions. I like yours as well regarding the sandbag idea. Relatively inexpensive and if it's not effective you can take it back out with a little hard work which I'm not afraid of. I wouldn't like the aesthetic aspect of it for long term use since this area can be seen from my driveway and road but in keeping with the cost & time vs purpose idea of monitoring what happens with some heavy rains/floods it could be very useful. The only drawback I could see in my situation is as others have mentioned, if there was eventually some cutting of the existing dam around the sandbags.
Hey guys I hope to start my widening and deepening of the area and hope to dam it up afterwards in a couple of weeks. I appreciate all the past ideas and advice. Any "last minute" advice or further thoughts/ideas?
Heres a few more pics from today after some heavy rain today
That stream looks about right to support a lake of 15 to 40 acres or more. I think you will experience nothing but constant washouts, fish loss, and the addition of upstream undesirable fish. If it was mine, I would look elsewhere for a better pond site. A "proper" dam on that stream would cost many, many, thousand $, and flood way beyond your property. Just my opinion, YMMV.
Do some research into "digger" ponds. I read about them in a book called Earth Ponds by Tim Matson. The dam is actually built upstream of where you want the pond to be so the scouring action of fast moving water falling over the dam keeps a basin open.