Pond Boss Forums POND CONSTRUCTION Building a dam I think I have a leak around the overflow pipe

You don't need an entire unit of SeekLeak - waste of money for a project that small, I'd just alternate compacted hydrated clay and bentonite layer after layer and you'll be fine. Might be a good project in July/August when water level drops. The bad thing about a spillway leak is they will, due to physics and the fact water is a universal solvent, get worse annually. The good thing is they only leak when the pond is full...if one considers that a good thing. Way better than a dam or hydrostatic basin leak, anyhow. We already improved that leak for you, thankfully. At the end of the day, I wouldn't lose much sleep over it - but address when it's convenient. 50# bag of sodium bentonite powder will likely be enough - $13.