Engineer or Dam builder Needed

So I have been sitting pondering this for way too long. It is the first major step in setting up my homestead farm. Water, all of my dreams rely on water. Having it would make me the richest of men, being able to provide my family with the food I have grown. Able to keep animals knowing they can always get a drink not to mention somewhere for the kids to cool off and play. So I'm calling out to all engineers or dam builder's I need help, I need free advice please. (I have also made a 2 minute YouTube video so you can see the whole lot)

So here are my problems: I have a fairly decent size dam as pictured above, this is full after rain. About 4 years ago there was a flood which burst the dam wall. To fix it the previous owner used decomposing granite to create a new back wall, now whenever we get some rain it leaks straight out generally takes about 2 months. With the dam wall bursting it created a huge washout that goes through the middle of the property. This is where the dam water leaks to. I probably need to fix this first, I just have no idea about this one I think I may have to keep saving and get heavy equipment in and scrape the bottom of the dam and put it over the wall.

Picture above is the washout. I have also made a 2 minute YouTube video so you can see the whole lot. What I'm wanting to do is maybe turn washout into another dam. But I need to do it cheaply and preferably myself. I had maybe thought of sand bagging the back of the washout (zone 3 )to create a wall. I can get the bags for about twenty cents each and fill them with dirt and start stacking them one meter wide by about two meter high. As I get close to the top I was thinking I could use about 15 to 20 pvc pipes as over flow. Run the pipes back to ground level into where the over flow keeps going through state land, as to not make it any worse.

Please ReSteem for me this would help resolve my issue quicker as I may wait a while for help and I want to act on this now before the summer rains.