What's Below has a different means to solve a leaky lake. It is not expensive because it is a very quick repair when compared to all other types of repairs available.
Mud hole instead of a lake is what we had to start.
Sodium bentonite treatments in the lake water and on the bank. The bentonite is a chipped clay that expands when wet. After about a week the bentonite will blanket the area to seal the leaky soil.
After treatments by What's Below, it is now a beautiful lake.