Ed,
Excellent photos depicting the toe drain work...almost looks like we use the same photographer.
Is the toe drain trench filled with gravel, kinda like a reverse septic field (or more accurately, like a french drain)? Also, it looks like your toe drain is located at the base, likely a number of feet behind the centerline (or core, if required)of the dam....correct?
V interesting...new for me. My reaction would have been that if there is enough anticipated seepage to warrant a toe drain, there may be reason to re-consider the construction engineering and integrity of the dam...or the entire project. It seems kinda creepy to think that one would see a constant trickle/flow out of toe drain embedded in an earthen dam holding back a substantial mass of water. How is it's need calculated?...and...how is it's performance predicted?
