The two spillways on opposite ends of the dam were designed to take the excess water that the overflow drain could not handle. They are a vast improvement over the single spillway we had originally on the south end of the dam that was really little more than a crease in the hillside, much too close to the dam itself.
As Libby said several times on our visit last Friday, it must have been both awesome and terrifying to see the overflow overwhelm the dam’s capacity.
The photo above shows the top of the northern spillway. That gouge in the ground drops four feet before heading down the hill. Had the erosion continued another ten feet (to the right), the dam would have been breached and likely the lake would have been emptied.
Here is another view of the top of the north spillway:
I’m trying to imagine the force of the water as it did this. Awesome and terrifying, indeed.
Here is a view of the north spillway from below:
Even sure-footed, crazy Flike was careful as he made his way down this slope. Most of that exposed bedrock you see had been buried before; only the smooth tops of two parts of it had been exposed. Now it serves as the side of the spillway.
This northern spillway is still somewhat intact. The berm/retaining wall (on the left in the photo immediately above) is still in place, though another big water event would likely chew through it.
The south spillway is pretty much gone altogether.
This is looking down from the top of the south spillway. The drop off you see in the foreground is about five feet from the slab of bedrock to what’s left of the soil and gravel that had comprised the spillway itself and its berm.
Here is another view from the top:
All of that gravel you see down in the pecan plantation is from the spillway and its berm. The flow had pushed rocks the size of tabletops down the hill. Fortunately, none of the plantings (pecans and a few cypress) in the area were damaged. That lonely looking little tree you see on the right was growing in the dry-side of the berm. Conventional wisdom says to remove these as they can fall and pull the earthen wall down with them. I thought otherwise, believing that its roots might actually help hold the wall together. You can see that it survived, though its retention powers were no match for the deluge.
This photo shows the southern spillway from below. See the lonely tree at about 9:00? Notice also, the grass at the lower right and how it is all laying down, pointing downhill. That is from when the water went over the top of the dam and flowed down the face of it, which is something you never want to happen.
Fortunately, the dam is still standing and holding back the water. Barring any big water events before the repairs can be made, there should be no utter disaster. Other than to my bank account, that is.
The man who built the dam had come out over the weekend to survey the damage. To his eye, it didn’t seem too bad. (He has an experienced eye. When I had called him, he wasn’t available, his wife telling me that he was out inspecting other ill-fated dams in the county.) He gave me a quote on what he thought it would cost to put things right, and the number came in much, much lower than I had expected (so I will be able to buy groceries for a few more months). He said he won’t be able to get out to do the repairs for a couple of weeks, so I’m crossing my fingers that the rain in the forecast for the next ten days won’t be significant.