Yes, it is a problem. You cannot compact water-saturated clay.

Since you are building in a ravine, your pond will almost certainly require a well-compacted core trench. Any significant water in the bottom of the core trench will make it impossible to achieve proper compaction.

I like your idea of an upstream temporary dam. A gravity drain is much easier to keep running than a pump. The 4" corrugated flexible drain tile pipe is only $0.75/foot at our local Menards. With only a 5' drop that pipe would handle about 180 gpm of flow from your spring.

One option would be to run that kind of pipe around one side of your pond construction site to a point in the ravine downstream of your dam location. When you are done with most of the construction on the opposite side, lift the inlet side of the pipe to let the water drain out, and then move the pipe to the other side of your pond construction site.

Even outside of the core trench, wet ground on the job site just slows everything down. Building a good water bypass should quickly pay for itself by saving hours of low-productivity time on the heavy equipment.

Further, you do need some water to moisten the clay to the proper water content prior to the compaction of each lift. Your upstream pond could be the source when the construction crew needs water on site.



Crazy idea alert!

Many people on Pond Boss would love to have a small pond upstream of their main pond. There are multiple benefits.

The first is to use it as a silt settlement pond. As soon as your main pond fills with water, it will start losing some depth over time due to silt and muck. You can design your upstream pond to catch a significant portion of that silt. Ten years in the future, you could cheaply clean out the upstream pond and then let it protect your main pond for another ten years.

The second use could be even more beneficial. You could use the upstream pond as a forage pond. Grow out minnows in the first two years of life for your main pond, open the valve on a 4" or 6" pipe, and drain that abundant forage into your main pond.

A few years later you could put in a few pairs of brooder BG and when the spawned BG have grown to the optimum size for your bass, flush them into the main pond. (Just an example, since I don't know your fish goals.)

Good luck on your pond project. A nice pond in a 20' deep ravine sounds like it could be a real beauty!

P.S. There are lots of very knowledgeable Pond Boss people in E. Texas. You should be able to get tons of local, expert advice when you start asking questions about fish stocking, etc.